Caracter|zac|n Geoqu|m|ca de |os Sha|esen Co|omb|aMlCuLL lL8nAnuC !lMLnLZ !ACCMLCelogo, M.Sc.Asesor Crupo de Ceologla de Cuencasvlcepresldencla 1ecnlcaAgencla naclonal de Pldrocarburosarte 1Conceptos Genera|esQue Es Una Roca Generadora?Cualquier roca quequetiene la capacidad de generar y expulsar suficientes hidrocarburos para formar acumulaciones comerciales de petrleo y/o gas (Hunt, 1996).Rocas Generadoras /Definiciones BsicasQue Es El Kergeno?Es la fraccin remanente (insoluble) de la materia orgnica, despus que una muestra de roca pulverizada ha sido atacada con solventes orgnicos (Petersy Cassa, 1994).Que Es El Bitumen?Es la fraccin orgnica de un sedimento que es extrable con solventes orgnicos (Tissoty Welte, 1984).Rocas Generadoras /Definiciones BsicasCondiciones Ideales Para LaFormacin De Rocas Generadoras EfectivasAlta Productividad Biolgica dentro o hacia el sitio del depsitoCondiciones anxicasen el ambiente de depsitoTasas de sedimentacin medias a bajasSedimentacin preferencial de rocas de grano finoDe acuerdo con estas condiciones,los ambientes mas favorables para lapresencia de rocas generadoras son:LagosDeltasAmbientes marinos de plataformaConsideraciones Generales Sobre Las Rocas GeneradorasUna roca generadora esta definida como cualquier roca capaz de generar y expulsar petrleo para formar acumulaciones de aceite y gas (HUNT, 1996).La capacidad general de una roca para generar petrleo o gas esta controlada por tres factores principales; calidad, cantidad y grado de evolucin trmico de la materia orgnica (Tissotet al, 1984). Los dos primeros factores a su vez estn controlados por caractersticas propias del ambiente de depsito como la productividad biolgica, el nivel de preservacin, la tasa de sedimentacin de la materia orgnica y el tamao de grano de los sedimentos (Damaisonet al, 1980). A escala global en los ecosistemas marinos pueden identificarse diferentes tendencias en la productividad biolgica (Allenet al,1990): la productividad primaria decrece desde la lnea de costa hacia las condiciones de mar abierto; latitudes medias y latitudes ecuatoriales son mas productivas que latitudes tropicales y las productividades mas bajas se presentan en las zonas polares y enreas tropicales ridas. Por su parte en los ecosistemas continentales la productividad de las plantas terrestres esta controlada bsicamente por el clima. La materia orgnica derivada de plantas esta constituida principalmente por turba, la cual es incorporada a las corrientes de los ros y transportada hasta los lagos y las reas marinas. Consideraciones Generales Sobre Las Rocas GeneradorasConsideraciones Generales Sobre Las Rocas GeneradorasLa productividad orgnica vara significativamente de ecosistemas continentales a marinosContinentalesPlantas terrestresAlgasMarinosPlantas terrestres y fitoplanctonFitoplanctonDelticoPlataformaLlanura AluvialLagoLa preservacin de la materia orgnica depositada en ecosistemas continentales o marinos esta ntimamente ligada a las condiciones de anoxadel ambiente. El trmino anxicoes frecuentemente usado en el sentido de un ambiente agotado en oxgeno(Tissot et al, 1984, Allen et al, 1990, Hunt, 1996,). En general los condiciones anxicas se desarrollan en aquellos ambientes donde la demanda de oxgeno excede la oferta del mismo.Consideraciones Generales Sobre Las Rocas GeneradorasAmbientes Anxicos Formadores de Rocas Madre1. GRANDES LAGOS ANXICOSEjemplo: Lago TanganikaDemaison& Moore(1980)

Lagos Profundos de clima hmedo y caliente.

Tanganika: profundidad mxima de ~1500my condiciones anxicasdesde los 50m de profundidad.Consideraciones Generales Sobre Las Rocas Generadoras2. CUENCAS MARINAS RESTRICTASEjemplo: Mar Negro

Presencia de barreras fisiogrficas.

Balance hidrolgico positivo (clima hmedo).

Haloclinapermanente (150-250m de profundidad.Consideraciones Generales Sobre Las Rocas GeneradorasAmbientes Anxicos Formadores de Rocas MadreDemaison& Moore(1980)Ambientes Anxicos Formadores de Rocas Madre2. CUENCAS MARINAS RESTRINGIDASEjemplo: Mar Negro

Mayores concentraciones de materia orgnica coinciden con reas anxicasy nocon reas de alta bioproductividad.Consideraciones Generales Sobre Las Rocas GeneradorasDemaison& Moore(1980)Ambientes Anxicos Formadores de Rocas Madre3. Zonas de UpwellingEjemplo: Margen W de Suramrica (Peru)

Alta productividad primaria

Demanda vs. suministro de oxgenoConsideraciones Generales Sobre Las Rocas GeneradorasDemaison& Moore(1980)Ambientes Anxicos Formadores de Rocas MadreConsideraciones Generales Sobre Las Rocas Generadoras4. DEPRESIONES RESTRINGIDAS EN MAR ABIERTOEjemplo: Cuenca de Orca (GOM)

Depresin de 400km2y 2400m de profundidad formada por halocinesis.

Haloclinapermanente y fondo anxico.5. OCEANOS ABIERTOS ANXICOSEjemplos: Mar de Oman, reas del ndico

reas ricas en nutrientes y/o con deficiencia de oxgeno controladas con condiciones particulares de corrientes ocenicas o climticas.Eventos Anxicos GlobalesOCEANIC ANOXIC EVENT (OAE)

Fases de deposicin generalizada en diferentes partes del mundo de shalesnegros ricos en materia orgnica.

Principales eventos: OAE 1a(AptianoTemprano), OAE 1b(AlbianoTemprano), OAE 2(CenomanianoTardo/TuronianoTemprano), OAE 3(edad Coniaciano/Santoniano).

Periodos de intenso sea-floor spreadingy vulcanismo, clima caliente y homogneo (mares ~10-15C> hoy) y nivel de mar alto, favoreciendo la implantacin de condiciones anxicasestables.

Productividad alta??Consideraciones Generales Sobre Las Rocas GeneradorasConsideraciones Generales Sobre Las Rocas GeneradorasOAE 2-CenomanianoTardo/TuronianoTempranoLa tasa de sedimentacin puede influenciar la presencia de rocasgeneradoras de formas opuestasConsideraciones Generales Sobre Las Rocas GeneradorasBajo condiciones xicas, una alta tasa de sedimentacin favorece la preservacin de la materia orgnica, al reducir el tiempo durante el cual la materia orgnica esta expuesta a la degradacin1Cuando estas tasas son muy elevadas, la materia orgnica empieza a ser diluida en la gran cantidad de materia mineral y el resultado esuna roca de muy baja concentracin de materia orgnica (Damaisonet al, 1980).122Edad de las Rocas Madres vs. Reservas Mundiales de HCConsideraciones Generales Sobre Las Rocas Generadoras0.21.09.00.38.00.48.01.225.02.629.02.812.50.05.010.015.020.025.030.0ProterozoicCambrian-OrdovicianSilurianLower/Middle DevonianUpper Devonian-TournaisianViscan-SerpukhovianPennsylvanian-Lower PermianUpper Permian-Middle JurassicUpper JurassicNeocomianAptian-TuronianConiacian-EoceneOligocene-Miocene% Reservas por Edadde laRoca MadreDiagnesis, CatagnesisY MetagnesisDe La Materia OrgnicaDIAGNESIS:Proceso que ocurre en condiciones de poco enterramiento (algunos cientos de metros) y bajas temperaturas ( Bitumen-------> petrleo + gas + residuoEsta fase varia entre valores de 0.5 y 2.0 %RoMETAGNESIS:Es el ultimo estado de alteracin trmica significativa de la materia orgnica. Durante esta etapa la Generacin de metano disminuye y comienzan a formarse estructuras de grafito. La metagnesisocurre en el rango de temperatura de 200-250 C. Diagnesis, CatagnesisY MetagnesisDe La Materia OrgnicaDiagnesis, CatagnesisY MetagnesisDe La Materia OrgnicaTomado de HUNT (1996)VIDAActividad bacterial y reacciones qumicasa baja temperaturaMETAGENESISDIAGENESIS50 C200 C250 CKergenoBITUMENPETROLEOGRAFITOMETANOCATAGENESISDiagnesis,CatagnesisY MetagnesisDe La Materia OrgnicaD I A G N E S I SC A T E G N E S I SM E T A G N E S I SLIGNINA-CARBOHIDRATOS-PROTEINAS-LIPIDOSPolomerizacinCondenzacinAcidosFlvicosy HmicosKERGENOCRAQUEOACEITE Y GASCARBONORESIDUALGAS HUMEDOACEITE LIVIANODEGRADACINTRMICABIOMARCADORESPEQUEOSCAMBIOSCRAQUEOTissot& Welte, 198450C200CTipos de KergenoElKergeno Tipo I se refiere a aquel con un alto contenido inicial de hidrgeno. Este tipo de kergeno tiene un predominio de lpidos debido principalmente a la acumulacin selectiva de material algal. Es relativamente raro y es especialmente comn en ambientes lacustresde agua dulce (estratificados) o hipersalinos.Materia orgnica amorfa con colonias de Botryococcus(ambiente lacustrino)en muestras de la Formacin Carbonera (Piedemonte LLAO) (Tomado de Giraldo, 2002)LagosTipos de KergenoElKergeno Tipo II es el mas frecuente en muchas rocas generadoras del mundo. En general posee altos contenidos de hidrgenos y bajos contenidos de oxgeno. Este tipo de Kergeno normalmente se relaciona con sedimentos marinos donde ocurre la mezcla de materia orgnica derivada de fitoplancton, zooplancton y bacterias.Materia orgnica amorfa en muestras del Grupo Villeta, Quebrada Calamb-VSM.(Tomado de Giraldo, 2002)Plataforma marinaMateria orgnica leosa y amorfa en la muestras de la Formacin Carbonera (sector de Tauramena) (Tomado de Giraldo,2002)ElKergeno Tipo IIIse refiere a aquel que posee un bajo contenido inicial de hidrgeno y alto contenido de oxgeno. Este tipo de Kergeno normalmente se asocia a materia orgnica derivada de platas continentales (superiores) y es comparativamente el menos favorable para la Generacin de depetrleo. Tipos de KergenoMarino DelticoTipos de KergenoAdems de los tres tipos "clsicos" de kergeno, otros han sido propuestosTipo IV:es un kergeno que presenta contenidos muy bajos de hidrgeno, siendo compuesto predominantemente por inertinitacon poco a ningn potencial generador. Este tipo de kergeno es resultado de la oxidacin/retrabajamentode otros kergenos.Tipo II-S:se relaciona con sedimentos marinos carbonticos donde la ocurrencia de sulfato-reduccin asociada a la deficiencia de hierro resulta en un exceso de S que acaba incorporndose al kergeno (relacin S/C>0,04).Tipo I-S:esta relacionado a depsitos lacustre hipersalinos donde la asociacin de intensa sulfato-reduccin con una deficiencia de hierro resulta en un exceso de S que tambin acaba incorporndose al kergeno.arte 2At|as de Geoqu|m|ca Crgn|ca de Co|omb|aDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIACACUAN-PUTUhAYD ASINCeneraIItIesWeIIs and SeepsCrude DII uaIIty0eposItIonaI EnvIronmentsChromatographySource Pock CharacterIzatIonSource Pock uaIIty and haturIty hapsPetroIeum Systems (Crude-Pock CorreIatIons)CACUAN-PUTUhAYD ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIACeneraIItIes6The source rock geochemIcal InformatIon Interpreted for the CagunPutumayo 8asIn Includes TDC and PockEval PyrolysIs data from 2912 samples taken In 64 wells; addItIonally JJ5 organIc petrography samples from 56 wells were Interpreted.Crude oIl and extracts InformatIon from 124 bulk analysIs samples, 40J lIquId chromatography samples, JJ0 gas chromatography samples,582 bIomarker samples and 90 Isotopes samples were also Interpreted.TD 9715ftSea levelSCHEMATC CROSS SECTON PUTUMAYO BASNNWSEPaleozoicJurassicPaleogeneUpper CretaceousColor code according to the commission for the Geological Map of the World (2005)Lower CretaceousNeogene010000 ftCAGUAN - PUTUMAYO BASN LOCATON AND BOUNDARESPacific OceanCaribbean SeaVENEZUELABRAZLPERUECUADORPANAMACOLOMBACaliNeivaVillavicencio24S.F.R.ECUADORPERUP a c i f i c O c e a n737274757677782101234210123473727475767778BOUNDARESNorthwest: Eastern Cordillera Foothills fault system East: Structural high, including the Serrana de Chiribiquete (SCH) South: Ecuadorian-Peruvian nternational border Northeast: Sierra de la Macarena (SM) San Josedel GuaviareSCH02Paleozoic sedimentary rocks forming structural highsBasement highFlorenciaSMFrom Barrero et al., 2007From Barrero et al., 2007From Mojica et al., 2010BourcePeservolrBeolBondstoneBosementBholeDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIACACUAN-PUTUhAYD ASINWeIIs and SeepsThe number of wells and/or surface locatIons wIth geochemIcal InformatIon In the Cagun Putumayo 8asIn Is 116.DIlseeps are located at the northern and western parts of the basIn, as well as the oIl fIelds 7MOCOAFLORENCA6500007000007500008000008500009000009500001000000105000011000001150000300000350000400000450000500000550000600000650000700000750000800000850000050100kmsDIl and gas fIeldsWells wIth geochemIcal InformatIonDIl seepsCas seepsUndetermIned seepsCItIes/TownsOritoCapellaCostayacoHormigaLoroMaryBurdine/MaxineAlea|ap datum: |agna SIrgasCoord. orIgIn: 8ogotEASTERN CORDILLERAECUADORPERCACUAN-PUTUhAYD ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIACrude DII uaIIty Normal and lIght oIls wIth AP gravItIes rangIng from 10 to 40 and sulfur content between 0 and J are present In the basIn. There Is no straIght relatIonshIp between sulfur and AP gravIty, but oIls above J0 AP have sulfur values below 1, and oIls below J0 show hIgher dIspersIon In sulfur content wIth values up to J. ThIs suggests that In the basIn there are oIls wIth dIfferent thermal maturItIes,the more mature have hIgher AP gravIty and lower sulfur content; but there are also crudes that havIng sImIlar AP gravItIes have dIfferent sulfur contents, whIch mIght IndIcate bIodegradatIon, IncreasIng sulfur content, and/or dIfferent source rocks, consIderIng that oIls sourced from shales usually have lower sulfur content than oIls from carbonates (FIgure A). The sulfur content of most crude oIls Is lower than 1, and Its NI/7 ratIo below 0.5, suggestIng that they are produced from rocks deposIted In a marIne suboxIc envIronment wIth low terrIgenous organIc matter Input (FIgure C). There Is no dIrect relatIonshIp between depth and crude oIl qualIty, IndIcatIng that sImIlar qualIty oIls can be found at dIfferent stratIgraphIc levels, probably related to vertIcal mIgratIon In faulted reservoIrs. 8ut addItIonally there Is the fact that dIfferent AP gravIty oIls can be found at sImIlar depths, reflectIng dIfferent preservatIon (bIodegradatIon) and/or thermal maturItIes (FIgure 8).8LECEN0ABCCABALLOS Fm.PEPNO Fm.UNKNOWNVLLETA Fm.01020304050API Gravity0 1 2 3% S u I f u rMaturity051015202530354045505560API Gravity2000018000160001400012000100008000600040002000 0D e p t h ( F e e t )Biodegraded OilHeavy OiINormaI OiILight OiICondensates012Ni / V0 1 2 3% S u I f u rAnoxic MarineLacustrine or ContinentaI0eposItIonaI EnvIronmentsDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIACACUAN-PUTUhAYD ASIN The Phytane/nC18 vs PrIstane/nC17 graph IndIcates that most of the oIls have orIgIn from terrestrIal organIc matter (Type kerogen) deposIted In an oxIdIzIng envIronment and have suffered low bIodegradatIon. There are also some samples In the mIxed kerogen range suggestIng a source wIth terrestrIal and marIne organIc matter (Type and kerogens) deposIted In more reducIng condItIons (FIgure A). The PrIstane/Phytane vs Dleanane/CJ0 Hopane (Dleanane ndex) graph shows that most of the oIls have low oleanane Index values (0.2) and Pr/Ph values (2) whIch IndIcates that these oIls are generated from source rocks deposIted In shelf marIne envIronments. There are some samples wIth low oleanane Index values but hIgh Pr/Ph (2) IndIcatIng that these oIls were generated from source rocks deposIted In marIne deltaIc envIronments. The oleanane Index has been also used as an age IndIcator of the source rock, wIth hIgh oleanane values for oIls generated In CenozoIc rocks and low oleanane values In oIls from older rocks (FIgure 8). The PrIstane/Phytane vs CJ5/CJ4 Hopane (Homohopane Index) graph shows that most oIl samples have Pr/Ph values below 2 and CJ5/CJ4 Hopane below 1, IndIcatIng that these oIls were generated from sIlIcIclastIc rocks deposIted In a shelf marIne envIronment. AddItIonally there are some samples wIth low homohopane Index but hIgher Pr/Ph values (2) IndIcatIve of sIlIcIclastIc rocks deposIted In marIne deltaIc envIronments (FIgure C).LECEN0ABCCABALLOS Fm.MACARENA Fm.PEPNO Fm.RUMYACO Fm.UNKNOWNVLLETA Fm.0.1110100Phytane / nC180.1 110100P r i s t a n e / n C1 7Biodegradati onMaturityOxidixingReducingTerrestri alTypeKerogenTypeKerogenAlgal,ReducingEnvironmentMixedKerogen-012345Pristane / Phytane00.20.40.60.8 1O I e a n a n e / C3 0H o p a n eMarine Deltaic(CENOZOC)Shelf MarineMarine Deltaic(CRETACEOUS)012345Pristane / Phytane00.5 11.5 22.5 3C3 5/ C3 4H o p a n eMarine CarbonaticShelf MarineMarine DeltaicCACUAN-PUTUhAYD ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIA0eposItIonaI EnvIronments The lIquId chromatography data from oIls In the basIn are plotted In the ternary dIagram above, and theIr dIstrIbutIon IndIcate that oIls are well preserved havIng low bIodegradatIon (low NSD compounds). n summary, the crude oIls In the basIn correspond predomInantly wIth generatIng facIes deposIted In sIlIcIclastIc envIronments rangIng from marIne to deltaIc wIth an Important terrestrIal organIc matter Input. These rocks were deposIted durIng the Cretaceous consIderIng theIr low oleanane Index values correspondIng to the 7Illeta and Caballos formatIons. These crude oIls are of good qualIty wIth AP gravItIes above 25 and sulfur content below 1 for most of them, and are well preserved (low bIodegradatIon). Hydrocarbons have been found In reservoIrs correspondIng to the Caballos, 7Illeta and |acarena formatIons of Cretaceous age and the CenozoIc PepIno and PumIyaco formatIons. (saturates, aromatIcs and NSD compunds)10LECEN0CABALLOS Fm. PEPNO Fm. UNKNOWNVLLETA Fm.050100100500100500%NSO%AROMATIC%SATURATEChromatographyCrude oIl of the DrIto16 well shows predomInance of low molecular weIght paraffIns and PrIstane/Phytane ratIo close to 1.ThIs crude shows predomInance of trIcyclIcs over hopanes IndIcatIng hIgh thermal maturIty. The dIasteranes abundance suggests that the oIl was generated from clayrIch rocks but also Increased thermal maturIty.C 1 8C 1 7C 1 6C 1 5C 1 4C 1 3C 1 2C 1 1C 1 9C 2 1C 2 0C 2 2P r i s t a n eP h y t a n eC 1 0C 9C 2 3C 2 4C 2 5C 2 6WeII Orito - 16ChromatogramFragmentogram m/z 191Fragmentogram m/z 217DPCANIC CEDCHEhISTPY ATLAS DF CDLDhIA11CACUAN-PUTUhAYD ASINTricycIicsHopanesDiasteranesCACUAN-PUTUhAYD ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIAChromatographyCrude oIl of the UnIcornIo1 well shows a bImodal chromatogram wIth hIgh molecular weIght paraffIns abundance and very hIgh PrIstane/Phytane ratIo (5.0), IndIcatIng generatIon from organIc facIes deposIted In deltaIc envIronments.The predomInance of hopanes over trIcyclIcs IndIcates low thermal maturIty of the oIl. The low dIasteranes abundance suggests that the oIl was generated from claypoor rocks.WeII Unicornio - 1Pr/Ph = 5.2ChromatogramPrPhDiasteranesHopanesTricycIicsFragmentogram m/z 191Fragmentogram m/z 21712Source Pock CharacterIzatIonDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIACACUAN-PUTUhAYD ASIN13 The data obtaIned from pyrolysIs PockEval of rock samples the depletIon effect caused by the hIgh thermal maturIty of these rocks. The data also IndIcate that the CenozoIc rocks (|Irador, PumIyaco and Toroyaco formatIons) all have poor generatIon potentIal (FIgure A). The Dxygen ndex vs Hydrogen ndex dIagram (7an Krevelen dIagram) shows that rock samples from the Cretaceous Caballos, 7Illeta and |acarena formatIons have type oIlprone kerogen. There are also samples from these formatIons wIth type gasprone characterIstIcs. n the case of the CenozoIc unIts (|Irador, Arrayn, PumIyaco and Toroyaco formatIons) theIr samples are IndIcatIve of type gasprone kerogen to type 7 kerogen. The PaleozoIc samples have very low H values and correspond maInly wIth type 7 kerogen (FIgure 8). for Hydrogen ndex (H) and S2 peak, IndIcate that samples from the Cretaceous Caballos, 7Illeta and |acarena formatIons have good generatIon potentIal (H 200mg HC/g TDC and S2 5 mg HC/g rock). TakIng Into account that these unIts are deeply burIed In the basIn, the poor generatIon values obtaIned from some samples could reflectThe Tmax maturIty parameter vs Hydrogen ndex graph shows that many samples from the Cretaceous to CenozoIc unIts mentIoned, have reached early maturIty to oIl generatIon peak condItIons In the basIn (FIgure C).LECEN0ABCARRAYAN Fm.CABALLOS Fm.MACARENA Fm.MRADOR Fm.PALEOZOCRUMYACO Fm.TOROYACO Fm.UNKNOWNVLLETA Fm.0102030405060708090S2 (mgHC / gROCK)0100200300400500600700800900H y d r o g e n I n d e x ( m g H C / g T O C )Poor Generation Potential and/or High thermal maturityExcellent Generation Potential Low thermal maturity050100150200250300Oxygen Index (mg CO2 / gTOC)01002003004005006007008009001000H y d r o g e n I n d e x ( m g H C / g T O C )V370390410430450470490510530550Tmax (oC)02004006008001000H y d r o g e n I n d e x ( m g H C / g T O C )IIIIII0.5%RoImmatureMatureOvermature1.35%RoCACUAN-PUTUhAYD ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIASource Pock CharacterIzatIon DrganIc content (TDC) and S2 peak values IndIcate source rock oIl generatIon potentIal, thIs graph shows that there are samples from Cretaceous unIts (Caballos, 7Illeta and |acarena formatIons) wIth good to excellent oIl generatIon potentIal (S2 up to 50 mg HC/g rock and TDC up to 9). n the case of the CenozoIc unIts (|Irador, Arrayn, PumIyaco and Toroyaco formatIons) theIr samples IndIcate poor oIl generatIon potentIal (FIgure A).The vItrInIte reflectance (Po) InformatIon shows that the sedImentary sequence Is Immature or close to early maturIty In the basIn. ThIs behavIor does not correspond wIth the Tmax values IndIcatIve of early to oIl generatIon peak, and would not explaIn the oIl accumulatIons and crude oIl qualIty found In the basIn (FIgure 8). n summary, the best source rocks at the basIn, wIth good to excellent oIl generatIon potentIal Intervals are the Cretaceous rocks of the Caballos, 7Illeta and |acarena formatIons. The CenozoIc rocks of the |Irador, Arrayn, PumIyaco and Toroyaco formatIons have poor oIl generatIon potentIal. Tmax maturIty data IndIcates that the Cretaceous oIlprone formatIons are mature and the sources for the hydrocarbons In the basIn.14LECEN0LECEN0ABARRAYAN Fm.CABALLOS Fm.MACARENA Fm.MRADOR Fm.PALEOZOCRUMYACO Fm.TOROYACO Fm.UNKNOWNVLLETA Fm.0246810%TOC01020304050S 2 ( m g H C / g R O C K )ExcellentVery GoodGoodFairPoorUNKNOWNACAE-1ACAE-10ACAE-2ALEA-1AZUL GRANDE-2BAGRE WEST-1BURDNE-1CAFELNA-1CAMAN-1CAMAN-2CAMAN-4CALDERO-1CARBE-1CARBE-4CENCELLA-1CHGUACO-1CONDOR-1CONEJO-1DOLORES-1EVELYN-1GARZA-1GAVLAN WEST-1GAVLAN WEST-2GAVLAN-1AGUAMUES-1HORMGA-1XLAS CHCAS-1LOSADA S.E.-1LUCLLE-1MANDUR-1MANDUR-3MANDUR-5MRAFLOR-1NANCY-1ORTO SUR-1ORTO-20ORTO-80PNUNA-1PUERTO ASS-1PUTUMAYO-1QULL-1QULLACNGA-1QULLACNGA-2RO MOCOA-1RO PESCADO-1RO SEVLLA-1SETUKO-1SUCUMBO-2TAMBOR-1TAPR-1TEMBLON-1XTOROYACO-1TUCAN-1UMBRA-2VENADO-10.1110%Ro120001100010000900080007000600050004000300020001000 0D e p t h ( F e e t )ImmatureOvermature(Gas Window)O i I W i n d o wCaballos Fm. 7Illeta Fm. VItrInIte PefIectance (XPo)650000700000750000800000850000900000950000100000010500001100000115000030000035000040000045000050000055000060000065000070000075000080000085000023561112131618192021 222425282932330.2 %Ro0.4 %Ro0.6 %Ro0.8 %Ro3000003500004000004500005000005500006000006500007000007500008000008500006500007000007500008000008500009000009500001000000105000011000001150000123456789101112131415161718192021 22242526272830313334360.4% Ro0.5% Ro0.6% Ro0.7% Ro0.8% Ro0.9% RoSource Pock uaIIty and haturIty hapsDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIA151. ACAE-22. AZUL GRANDE-23. BAGRE WEST-14. BURDINE-15. CAFELINA-16. CALDERO-17. CARIBE-48. CONDOR-19. CONEJO-110. DOLORES-111. EVELYN-112. GARZA-1LECEN013.GAVILAN WEST-214. HORMIGA-1X15. LAS CHICAS-1 16. LUCILLE-117. MANDUR-118. MANDUR-319. MIRAFLOR-120. NANCY-121. ORITO SUR-122. ORITO-2023. PINUNA-124. PUERTO ASIS-125. QUILILI-126. QUILLACINGA-127. RO MOCOA-128. RO PESCADO-129. RO SEVILLA-130. SETUKO-131. SUCUMBIO-232. TEMBLN-1X33. TOROYACO-134. TUCN-135. URIBE-136. VENADO-1CACUAN-PUTUhAYD ASIN|ap datum: |agna SIrgasCoord. orIgIn: 8ogotCACUAN-PUTUhAYD ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIACaballos Fm. 7Illeta Fm. Hydrogen Index6500007000007500008000008500009000009500001000000105000011000001150000300000350000400000450000500000550000600000650000700000750000800000850000121622333550mg HC/g TOC150mg HC/g TOC250mg HC/g TOC350mg HC/g TOC650000700000750000800000850000900000950000100000010500001100000115000030000035000040000045000050000055000060000065000070000075000080000085000012162223 330mg HC/g TOC40mg HC/g TOC80mg HC/g TOC120mg HC/g TOC160mg HC/g TOC200mg HC/g TOCSource Pock uaIIty and haturIty haps161. ACAE-22. AZUL GRANDE-23. BAGRE WEST-14. BURDINE-15. CAFELINA-16. CALDERO-17. CARIBE-48. CONDOR-19. CONEJO-110. DOLORES-111. EVELYN-112. GARZA-1LECEN013.GAVILAN WEST-214. HORMIGA-1X15. LAS CHICAS-1 16. LUCILLE-117. MANDUR-118. MANDUR-319. MIRAFLOR-120. NANCY-121. ORITO SUR-122. ORITO-2023. PINUNA-124. PUERTO ASIS-125. QUILILI-126. QUILLACINGA-127. RO MOCOA-128. RO PESCADO-129. RO SEVILLA-130. SETUKO-131. SUCUMBIO-232. TEMBLN-1X33. TOROYACO-134. TUCN-135. URIBE-136. VENADO-1|ap datum: |agna SIrgasCoord. orIgIn: 8ogotCaballos Fm. 7Illeta Fm. DrganIc hatter Content (TDC) 6500007000007500008000008500009000009500001000000105000011000001150000300000350000400000450000500000550000600000650000700000750000800000850000691216223133350.6% wt0.9% wt1.2% wt1.5% wt1.8% wt65000070000075000080000085000090000095000010000001050000110000011500003000003500004000004500005000005500006000006500007000007500008000008500006 12162223 330.2% wt0.8% wt1.4% wt2% wt2.6% wtSource Pock uaIIty and haturIty haps1. ACAE-22. AZUL GRANDE-23. BAGRE WEST-14. BURDINE-15. CAFELINA-16. CALDERO-17. CARIBE-48. CONDOR-19. CONEJO-110. DOLORES-111. EVELYN-112. GARZA-1LECEN013.GAVILAN WEST-214. HORMIGA-1X15. LAS CHICAS-1 16. LUCILLE-117. MANDUR-118. MANDUR-319. MIRAFLOR-120. NANCY-121. ORITO SUR-122. ORITO-2023. PINUNA-124. PUERTO ASIS-125. QUILILI-126. QUILLACINGA-127. RO MOCOA-128. RO PESCADO-129. RO SEVILLA-130. SETUKO-131. SUCUMBIO-232. TEMBLN-1X33. TOROYACO-134. TUCN-135. URIBE-136. VENADO-1DPCANIC CEDCHEhISTPY ATLAS DF CDLDhIA17CACUAN-PUTUhAYD ASIN|ap datum: |agna SIrgasCoord. orIgIn: 8ogotCACUAN-PUTUhAYD ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIAPetroIeum Systems (Crude-Pock CorreIatIons)18 The PrIstane/Phytane vs Dleanane/CJ0 Hopane (Dleanane ndex) graph shows that oIls from the Caballos, 7Illeta, PepIno and PumIyaco reservoIrs have low oleanane Index values (0.2) and Pr/Ph values (2), and correlate well wIth rock extracts from the 7Illeta and Caballos formatIons, suggestIng that these unIts are the sources for the hydrocarbons found In those reservoIrs at the basIn. AddItIonally the low oleanane values correlate well wIth the Cretaceous age of the sources (FIgure 8). (FIgure A). The Phytane/nC18 vs PrIstane/nC17 graph shows good correlatIon between the crude oIls found In the Caballos, 7Illeta and PepIno reservoIrs wIth rock extracts from samples of the Caballos and 7Illeta formatIons. ndIcatIng that the oIls have orIgIn from terrestrIal organIc matter and to a mInor extent from mIxed kerogen (type ), but addItIonally that the crudes and rocks have sImIlar thermal maturItIes The steranes ternary plot shows good correlatIon of crude oIls from the Caballos, 7Illeta, PepIno and PumIyaco reservoIrs wIth rock extracts from Caballos and 7Illeta FormatIons, and that these rocks were deposIted In an estuarIne to marIne envIronment whIch Is conformable wIth terrIgenous Input and shelf marIne deposItIonal envIronment IndIcated by other parameters (c.e. PrIstane/Phytane, Dleanane ndex, Homohopanes ndex, PrIstane/ nC17) (FIgure C).LECEN0ABC100908070605040302010001020304050607080901000102030405060708090100%C29 Steranes%C28 Steranes%C27 SteranesLACUSTRNETERRESTRALSUPERORPLANTSMARNEPLANKTONESTUARNESCRUDE- CABALLOS Fm.CRUDE- PEPNO Fm.CRUDE- RUMYACO Fm.CRUDE- VLLETA Fm.ROCK- CABALLOS Fm.ROCK- RUMYACO Fm.ROCK- VLLETA Fm.0.1110100Phytane / nC180.1 110100P r i s t a n e / n C1 7Biodegradati onMaturityOxidixingReducingTerrestri alTypeKerogenTypeKerogenAlgal,ReducingEnvironmentMixedKerogen-012345Pristane / Phytane00.20.40.60.8 1O I e a n a n e / C3 0H o p a n eMarine Deltaic(CENOZOC)Shelf MarineMarine Deltaic(CRETACEOUS)PetroIeum Systems (Crude-Pock CorreIatIons) The Homohopanes ndex (CJ5/CJ4 Hopane ratIo) vs dIasteranes/steranes graph shows good correlatIon between the crude oIls from the Caballos, 7Illeta and PepIno reservoIrs wIth rock extracts from the Caballos and 7Illeta formatIons, IndIcatIng also that these crudes were formed from rocks deposIted In suboxIc envIronments wIth varIable clay content (FIgure A). The Ts/(Ts+Tm) vs dIasteranes/steranes graph shows good correlatIon between crude oIls from the Caballos, 7Illeta and PepIno formatIons wIth rock extracts from the Caballos and 7Illeta formatIons. n thIs graph there Is better correlatIon of Caballos formatIon crudes wIth 7Illeta formatIon extracts than wIth Caballos formatIon extracts, and of 7Illeta formatIon oIls wIth Caballos and 7Illeta extracts. AddItIonally thIs graph suggests that oIls were formed from claypoor rocks.Crude Pock correlatIons from samples at the basIn suggest the followIng: Cood correlatIon between crudes from the Caballos, 7Illeta and PepIno reservoIrs and extracts from the 7Illeta and Caballos formatIons (low dIasteranes/steranes, low Ts/Tm, CJ5/CJ4 hopane ratIo 1, low oleanane Index, PrIstane/Phytane 2, and predomInance of C27/C29 steranes). ThIs IndIcates the presence of several actIve petroleum systems at the basIn named as follows: Caballos (!), Caballos (!), 7Illeta (!), 7Illeta PepIno (!) and Caballos PepIno (!).7Illeta DPCANIC CEDCHEhISTPY ATLAS DF CDLDhIA1CACUAN-PUTUhAYD ASINLECEN0AB024681012Diasteranes / Steranes00.40.81.21.6 2C 3 5 / C 3 4 H o p a n e R a t i oDECREASNG CLAY CONTENT (CARBONATES) OR HGH REDUCNG CONDTONS (ANOXC)NCREASNG CLAY CONTENT (SHALES) ORLOW REDUCNG CONDTONS (OXC)CRUDE- CABALLOS Fm.CRUDE- PEPNO Fm.CRUDE- RUMYACO Fm.CRUDE- VLLETA Fm.ROCK- CABALLOS Fm.ROCK- RUMYACO Fm.ROCK- VLLETA Fm.024681012Diasteranes / Steranes00.40.81.21.6 2T s / ( T s + T m )NCREASNG CLAY CONTENTDECRESNG CLAY CONTENT (CARBONATES)DPCANIC CEDCHEhISTPY ATLAS DF CDLDhIACATATUhD ASINCeneraIItIesWeIIs and SeepsCrude DII uaIIty0eposItIonaI EnvIronmentsChromatographySource Pock CharacterIzatIonSource Pock uaIIty and haturIty hapsCas CharacterIzatIonFrom Barrero et al, 2007FluvialU r i b a n t e G r .STRATGRAPHCUNTSFluvialStreamAguardienteCapacho Fm.La Luna Fm.Coln Fm.Mito-Juan Fm.Catatumbo Fm.Barco Fm.Los Cuervos Fm.Mirador Fm.Carbonera Fm.Len Fm.Guayabo Fm.N E O G E N EP A L E O G E N EC R E T A C E O U SJ U R A S S CMercedesTibRo NegroGirn Gp.La Quinta Fm.LTHOLOGYENVRONMENTCeneraIItIesThe source rock geochemIcal InformatIonInterpreted for the Catatumbo 8asInIncludes TDC and PockEval PyrolysIsdata from 1195 samples taken In JJ wells;addItIonally J4J organIc petrography samples from 21 wells were Interpreted.Crude oIl InformatIon from 146 bulkanalysIs samples, 2J5 lIquId chromatographysamples, 275 gas chromatography samples,242 bIomarker samples and 170 Isotopessamples were also Interpreted.CATATUhD ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIA21Pacific OceanCaribbean SeaVENEZUELABRAZLPERUECUADORPANAMACOLOMBABarranquillaSanta MartaValleduparCucutaBucaramangaVENEZUELAB.S.M.F.03CATATUMBO BASN LOCATON AND BOUNDARES7891011727173747572717374757891011BOUNDARESNorth: Geographic Border with Venezuela South: Eastern Cordillera Cretaceous rocks West: Santader Massif igneous and metamorphics East: Geographic Border with VenezuelaB.S.M.F. Bucaramanga-Santa Marta Fault SystemFrom Barrero et al., 2007Catatumboflexure zoneEasternflexure zoneSCHEMATC CROSS SECTONCATATUMBO BASNWEBasementLower CretaceousCenozoicUpper CretaceousColor code according to the commission for the Geological Map of the World (2005)10Km1000m0scale approx..Modified from Yurewicz, et al., 1998From Barrero et al., 2007CATATUhD ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIAWeIIs and SeepsThe number of wells and/or surface locatIons wIth geochemIcal InformatIon In the Catatumbo 8asIn Is 56.Seeps are located at the northwestern and eastern parts of the basIn. DIl fIelds are mostly located to the east of the basIn.22CUCUTA112000011400001160000118000013400001360000138000014000001420000144000014600001480000150000001020KmsDIl and gas fIeldsWells wIth geochemIcal InformatIonDIl seepsCas seepsUndetermIned seepsCItIes/TownsPuerto BarcoRo de OroTib - SocuavoYucaSardinataPetroleaCarboneraRo ZuliaVENEZUELAEASTERN CORDILLERA|ap datum: |agna SIrgasCoord. orIgIn: 8ogotTBPUERTOSANTANDERCrude DII uaIItyCATATUhD ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIA23 Normal and lIght oIls wIth AP gravItIes rangIng from 25 to 45 and sulfur content between 0 and 1.2 are present In the basIn. There Is a straIght relatIonshIp between sulfur and AP gravIty, showIng that hIgh AP gravIty mature oIls have low sulfur content regardIng low AP gravIty less mature oIls. (FIgure A). The sulfur content of most crude oIls Is lower than 1, and Its NI/7 ratIo below 1, suggestIng that they are produced from rocks deposIted In a marIne suboxIc to anoxIc envIronment wIth marIne organIc matter Input (FIgure C). There Is no dIrect relatIonshIp between depth and crude oIl qualIty, IndIcatIng that sImIlar qualIty oIls can be found at dIfferent stratIgraphIc levels, probably related to vertIcal mIgratIon In faulted reservoIrs. 8ut addItIonally there Is the fact that dIfferent AP gravIty oIls can be found at sImIlar depths, reflectIng dIfferent preservatIon (bIodegradatIon) and/or thermal maturItIes (FIgure 8).The oIls of the Catatumbo 8asIn are of excellent qualIty, wIth hIgh AP gravIty and low sulfur content and Its hIgh thermal evolutIon explaIns the hIgh AP gravIty.LECEN0ABCAGUAS BLANCAS Fm.BARCO Fm.BARCO - LOS CUERVOS Fm. COGOLLO Fm. LA LUNA Fm.MTOJUAN Fm.UNKNOWNURBANTE Gr.051015202530354045505560API Gravity2000018000160001400012000100008000600040002000 0D e p t h ( F e e t )Biodegraded OilHeavy OiINormaI OiILight OiICondensates2030405060API Gravity00.40.81.21.6 2% S u I f u rMaturity012Ni / V0 1 2% S u I f u rAnoxic MarineLacustrine or ContinentaICATATUhD ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIA0eposItIonaI EnvIronments24 The Phytane/nC18 vs PrIstane/nC17 graph IndIcates that most of the oIls have orIgIn from mIxed terrestrIalmarIne organIc matter (Type kerogens), have suffered low bIodegradatIon and are thermally mature. There are some samples In the terrestrIal kerogen range suggestIng a source wIth terrestrIal organIc matter (Type kerogen) deposIted In more oxIdIzIng condItIons (FIgure A). The AP CravIty vs C29a88/C29a88+aaa graph, shows that oIls wIth hIgher AP gravIty has hIgher C29 IsomerIzatIon and close to equIlIbrIum (stabIlIty boundary) as a result of theIr hIgh thermal maturIty (FIgure 8). The PrIstane/Phytane vs CJ5/CJ4 Hopane (Homohopane Index) graph shows that most oIl samples have Pr/Ph values below 2 and CJ5/CJ4 Hopane above 1, IndIcatIng that these oIls were generated from rocks wIth varIable carbonatIc Input deposIted In a shelf marIne envIronment. AddItIonally there Is one sample wIth low homohopane Index but hIgher Pr/Ph values (2) IndIcatIve of sIlIcIclastIc rocks deposIted In marIne deltaIc envIronments (FIgure C).LECEN0ABAGUAS BLANCAS Fm.BARCO Fm.ESCANDALOSA Fm.MTOJUAN Fm.UNKNOWNURBANTE Gr.YURUMA SUPEROR Fm.LA LUNA Fm.COGOLLO Fm.0.1110100Phytane / nC180.1 110100P r i s t a n e / n C1 7Biodegradati onMaturityOxidixingReducingTerrestrialTypeKerogenTypeKerogenAlgal,ReducingEnvironmentMi xedKerogen-0102030405060API Gravity00.10.20.30.40.50.60.70.8C2 9 / C2 9

Maturi tyStability boundaryMarine CarbonaticShelf MarineMarine Deltaic012345Pristane / Phytane00.5 11.5 22.5 3C3 5/ C3 4H o p a n e0eposItIonaI EnvIronmentsCATATUhD ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIA25 n summary, the crude oIls In the basIn correspond predomInantly wIth generatIng facIes deposIted In marIne carbonatIc and sIlIcIclastIc envIronments, wIth low terrestrIal organIc matter Input. These rocks were deposIted durIng the Cretaceous consIderIng theIr low oleanane Index values and t correspond to the La Luna and Capacho formatIons and the UrIbante Croup. These crude oIls are of good qualIty wIth AP gravItIes above 25 and sulfur content below 1 for most of them, and are well preserved (low bIodegradatIon).The PrIstane/Phytane vs Dleanane/CJ0 Hopane (Dleanane ndex) graph shows that most of the oIls have low oleanane Index values (0.2) and Pr/Ph values (2) whIch IndIcates that these oIls are generated from source rocks deposIted In shelf marIne envIronments. There Is one sample wIth low oleanane Index values but hIgh Pr/Ph (2) IndIcatIng that these oIls were generated from source rocks deposIted In marIne deltaIc envIronments. The oleanane Index has been also used as an age IndIcator of the source rock, wIth hIgh oleanane values for oIls generated In CenozoIc rocks and low oleanane values In oIls from older rocks. he CJ5/CJ4 Hopane ratIo above 1.0, suggests that the deposIt envIronment of the source rocks was anoxIc (carbonatIc), whIchLECEN0BARCO Fm.MTOJUAN Fm.UNKNOWNURBANTE Fm.012345Pristane / Phytane00.20.40.60.8 1O I e a n a n e / C3 0H o p a n eMarine Deltaic(CENOZOC)Shelf MarineMarine Deltaic(CRETACEOUS)CATATUhD ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIAChromatographyThe crude oIl of the TIbuJ66 well Is characterIzedby showIng In gas chromatography, predomInanceof low molecular weIght paraffIns (hIgh thermalmaturIty) and PrIstane/Phytane ratIo 1.0..The hIgh degree of thermal evolutIon of the oIl has reduced the hopanes and steranes abundance and Increased the trIcyclIcs In the oIl51015202530counts10000200003000040000500006000070000FID1 A, (GEOQ1107\2897755.D)N - C 1 1N - C 1 2N - C 1 3N - C 1 4N - C 1 5N - C 1 6N - C 1 7P r i s t a n eN - C 1 8P h y t a n eN - C 1 9N - C 2 0N - C 2 1N - C 2 2N - C 2 3N - C 2 4N - C 2 5N - C 2 6N - C 2 7N - C 2 8N - C 2 9N - C 3 0WeII Tib - 366Chromatogrammin20.0025.0030.0035.0040.0045.0050.0055.0060.0065.0070.0075.00200040006000800010000120001400016000Time-->AbundanceIon 191.00 (190.70 to 191.70): C-TIB366.D20.0025.0030.0035.0040.0045.0050.0055.0060.0065.0070.0075.00500100015002000250030003500AbundanceIon 217.00 (216.70 to 217.70): C-TIB366.DTime-->Fragmentogram m/z 191Fragmentogram m/z 21726TricycIicsHopanesDiasteranesSource Pock CharacterIzatIon27CATATUhD ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIA The data obtaIned from pyrolysIs of rock samples the depletIon effect caused by the hIgh thermal maturIty of these rocks. The data also IndIcate that most of the CenozoIc rocks (|Irador, Los Cuervos, Leon and Cuayabo formatIons), have poor generatIon potentIal wIth the exceptIon of the 8arco and Carbonera formatIons whIch have samples wIth good generatIon potentIal (FIgure A). The Dxygen ndex vs Hydrogen ndex dIagram (7an Krevelen dIagram) shows that rock samples from the Cretaceous UrIbante Croup and La Luna, Capacho and Catatumbo formatIons, along wIth the CenozoIc 8arco and Carbonera formatIons have type oIlprone kerogen. Some samples of these unIts also have type kerogen values. The Cretaceous |ItoJuan FormatIon and the CenozoIc unIts (|Irador and Los Cuervos formatIons) have samples predomInantly of type gasprone kerogen to type 7 kerogen. (FIgure 8). for Hydrogen ndex (H) and S2 peak, IndIcate that most samples have poor generatIon potentIal (H 200mg HC/g TDC and S2 5 mg HC/g rock), and there are few samples wIth good generatIon potentIal (H 200mg HC/g TDC and S2 5 mg HC/g rock).n the case of the Cretaceous rocks should be consIdered that these unIts are deeply burIed In the basIn, and the poor generatIon values obtaIned from some samples could reflectThe Tmax maturIty parameter vs Hydrogen ndex graph shows that many samples from the Cretaceous to CenozoIc unIts mentIoned, have reached early maturIty to overmature condItIons In the basIn, beIng the Cretaceous unIts more mature than the CenozoIc unIts, explaInIng the hIgh thermal maturIty IndIcated by the oIls found In the basIn (FIgure C).LECEN0ABC370390410430450470490510530550Tmax (oC)0200400600H y d r o g e n I n d e x ( m g H C / g T O C )IIIIII1.35%Ro0 . 5 % R oImmatureMatureOvermatureBARCO Fm.CARBONERA Fm.CATATUMBO Fm.COGOLLO Fm.COLN Fm.COLON/LA LUNA Fm.CAPACHO Fm.GUAYABO Fm.LA LUNA Fm.LA LUNA/COGOLLO Fm.LEN Fm.LOS CUERVOS Fm.MRADOR Fm.MTO JUAN Fm.OSTREA Fm.UNKNOWNURAMTA Fm.URBANTE Gr.010203040S2 (mgHC / gROCK)0100200300400500H y d r o g e n I n d e x ( m g H C / g T O C )Poor Generation Potential and/or High thermal maturityExcellent Generation Potential Low thermal maturity050100150200250Oxygen Index (mg CO2 / gTOC)0100200300400500H y d r o g e n I n d e x ( m g H C / g T O C )VCATATUhD ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIASource Pock CharacterIzatIon28 DrganIc content (TDC) and S2 peak values IndIcate source rock oIl generatIon potentIal, thIs graph shows that there are samples from Cretaceous unIts (UrIbante Croup, La Luna, Capacho and Catatumbo formatIons) and CenozoIc unIts (8arco, Los Cuervos and Carbonera formatIons), wIth good to excellent oIl generatIon potentIal (S2 up to J5 mg HC/g rock and TDC up to 9). n the case of the Upper Cretaceous |ItoJuan FormatIon and the CenozoIc Cuayabo and Leon formatIons theIr samples IndIcate poor oIl generatIon potentIal (FIgure A). CThe vItrInIte reflectance (Po) InformatIon shows that the sedImentary sequence deposIted In the basIn Is mostly mature to overmature whIch Is In good agreement wIth the AP CravIty and hIgh thermal maturIty of the oIls found (FIgure 8). n summary, the best source rocks at the basIn, wIth good to excellent oIl generatIon potentIal Intervals are the Cretaceous rocks of the UrIbante Croup, and La Luna, Capacho and Catatumbo formatIons. The CenozoIc rocks of the 8arco and Carbonera formatIons also have good to excellent generatIon potentIals. Thermal maturIty data (Tmax and Po) IndIcates that the Cretaceous oIlprone formatIons are the more mature sources for the hydrocarbons In the basIn, and that the CenozoIc 8arco and Carbonera formatIons are also In an earlIer maturIty stage In the basIn. (S2 5 mg HC/g rock and TDC 1)eneratIon potentIal Is reduced by hIgh thermal maturIty, especIally In unIts lIke La Luna and Capacho formatIons and the UrIbante Croup.LECEN0LECEN0AB0246810%TOC010203040S 2 ( m g H C / g R O C K )ExcellentVery GoodGoodFairPoorBARCO Fm.CARBONERA Fm.CATATUMBO Fm.COGOLLO Fm.COLN Fm.COLON/LA LUNA Fm.CAPACHO Fm.GUAYABO Fm.LA LUNA Fm.LA LUNA/COGOLLO Fm.LEN Fm.LOS CUERVOS Fm.MRADOR Fm.MTO JUAN Fm.OSTREA Fm.UNKNOWNURAMTA Fm.URBANTE Gr.CARBONERA-4KCARBONERA-5KCERRTO-1CERRO GORDO-1CERRO GORDO-3ESPERANZA-3LEONCTO-2MUCURERA-3PETROLEA-108PETROLEA-90PETROLEA-91RO DE ORO-14KRO ZULA-14SARDNATA-3KTBU-178KTBU-2KTBU-408KTBU-87TBU-91KSARDNATA-10.1110%Ro120001100010000900080007000600050004000300020001000 0D e p t h ( F e e t )ImmatureOvermature(Gas Window)O i I W i n d o wSource Pock uaIIty and haturIty haps7ItrInIte Peflectance (Po)Hydrogen ndex La Luna FormatIonDrganIc |atter Content (TDC)1120000114000011600001180000134000013600001380000140000014200001440000146000014800001500000134567891112130.1% Ro0.8% Ro1.5% Ro2.2% Ro2.9% Ro112000011400001160000118000013400001360000138000014000001420000144000014600001480000150000012345691011121314150mg HC/g TOC40mg HC/g TOC80mg HC/g TOC120mg HC/g TOC160mg HC/g TOC112000011400001160000118000013400001360000138000014000001420000144000014600001480000150000012345691011121314150% wt2.5% wt5% wt7.5% wt2CATATUhD ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIA1 .CARBONERA-4K2. CARBONERA-5K3. CERRITO-14. CERRO GORDO-35. ESPERANZA-36. MUCURERA-37. PETROLEA-1088. PETROLEA-919. RO DE ORO-1410. RO ZULIA-14LECEN011. SARDINATA-3K12. TIBU-178K13. TIB-2K14. TIB-91K15. ZULIA EAST-1|ap datum: |agna SIrgasCoord. orIgIn: 8ogotCATATUhD ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIACas CharacterIzatIon30 8IogenIc gasT Crude oIl gasesTolTc Crude and condensate gasesTT(m) 0ry gases assocIated to sapropelIc organIc matter.TT(h) Cases assocIated to humIc organIc matterh |Ixed gaseshd 0eep |IgratIonhs Shallow |IgratIonLECEN001020304050C2 + (%)-20-25-30-35-40-45-50-55-60-65-70-75

CC H 4( p p t )BMTOMsTT(m)MdTCTT(h)Ro12%20%30%Migration?Mixed ShaIIowDeepCARBONERA Caa BravaCERRTO-1PETROLEA-29RO ZULA-29SARDNATA N3KSARDNATA S32KTBU -4KTBU 191KTORTEROS04812C2 / C3 (moI/moI)-16-14-12-10-8-6-4-2 0 2 4 C1 3C2-C1 3C3( % P D B )Open system trendNSO secondary crackingHydrocarbons secondarycrackingPrimarycrackingGas secondary crackingClose systemtrend0.9 - 1.11.3 - 1.51.8 - 2.0Ro %-20-30-40-50-60-70EarlyLateBTOiITT(m)TT(h) m m a t u r e / t e r t i a r yD i a gT e r t i a r y b a s i nM a t u r e / M e s o z o i cO v e r m a t u r e / P a l e o z o i c0.51.22.03.01.22.03.0 Ro(%)

CCH4(ppt) The samples analIzed In the Catatumbo 8asIn Include gases assocIated to samples from coal mInes (Torteros and Caa 8rava Carbonera). The C2+() vs d1JC Ch4 (ppt) dIagram (Schoell, 198J), suggests that the well samples correspond to thermogenIc gases, sourced from organIc matter at dIfferent maturIty levels. These gases IndIcate deep to shallow mIgratIon. Dn the other hand the gas samples taken from the El Tortero and Caa 8rava Carbonera mInes, correspond to humIc organIc matter sources. The C2/CJ vs d1JC CJ dIagram, suggests that the gas samples analIzed were orIgInated by prImary crackIng.CAUCA- PATA ASINCeneraIItIesWeIIs and Seeps0eposItIonaI EnvIronmentsSource Pock CharacterIzatIonSurface CeochemIstry DPCANIC CEDCHEhISTPY ATLAS DF CDLDhIACAUCA- PATA ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIACeneraIItIesNWWSEECROSS SECTONCAUCA-PATA BASNCretaceousPaleogeneNeogeneTaken from Barrero-Lozano D., et al. 2006VENEZUELABRAZLPERUECUADORPANAMACOLOMBABogotCaliPasto22P a c i f i c O c e a n.Z.F.G.S.F.RECUADORCAUCA - PATA BASN LOCATON AND BOUNDARES12345674757677797874757677797812345623BOUNDARESWest: Cauca fault system (C.F.S.), Western Cordillera volcanic and sedimentary rocks (23)East: Cordilera (22)Romeral fault system (R.F.S.), Central04PopayanC. F . S.G.F.Z. Garrapatas fault system Ro Guabas/AguaClara, Chapungo/NogalesP.Morada/ChimborazoMosquera/GuachinteDiabasico/AmaimeSTRATGRAPHCUNTRidge and plateau basaltsCollision relatedoceanic basinRemnantoceanic basinFirst obliquecollisionMolasseThe source rock geochemIcal InformatIon Interpreted for the Cauca Patia 8asIn Includes TDC and PockEval PyrolysIs data from J26 samples; addItIonally 96 organIc petrography samples were Interpreted.Crude oIl InformatIon from 54 lIquId chromatography samples, J95 gas chromatography samples, 24 bIomarker samples, 66 Isotopes and 12J9 surface geochemIstry samples were also Interpreted.32From Barrero et al., 2007From Barrero et al., 2007From Barrero et al., 2007WeIIs and SeepsTwo seeps are reported at the southern part of the basIn and one In Its northern part.33DPCANIC CEDCHEhISTPY ATLAS DF CDLDhIACAUCA - PATA ASINPOPAYANCALPERERAARMENA6500007000007500008000006500007000007500008000008500009000009500001000000105000002550Kms|ap datum: |agna SIrgasCoord.orIgIn: 8ogotCENTRALCORDI LLERAWESTERNCORDI LLERADIl seepsCas seepsCItIes/Towns0eposItIonaI EnvIronments34DPCANIC CEDCHEhISTPY ATLAS DF CDLDhIACAUCA- PATA ASIN The Phytane/nC18 vs PrIstane/nC17 graph that the rock extracts from outcrop samples and two seep samples In the basIn have orIgIn from terrestrIal organIc matter (Type kerogen) deposIted In an oxIdIzIng envIronment. Another oIl seep sample wIth very hIgh Phytane/nC18 value suggests generatIon from marIne organIc matter (Type kerogen) In very reducIng condItIons (FIgure A). The PrIstane/Phytane vs Dleanane/CJ0 Hopane (Dleanane ndex) graph shows that half of the rock extracts have low oleanane Index values (0.2) and Pr/Ph values (2) whIch IndIcates that these oIls are generated from source rocks deposIted In shelf marIne envIronments, and the other half have low oleanane Index values but hIgh Pr/Ph (2) IndIcatIng that these extracts were generated from source rocks deposIted In marIne deltaIc envIronments. The oleanane Index has been also used as an age IndIcator of the source rock, wIth hIgh oleanane values for oIls generated In CenozoIc rocks and low oleanane values In oIls from older rocks (FIgure 8). The PrIstane/Phytane vs CJ5/CJ4 Hopane (Homohopane Index) graph shows that all the rock extracts have CJ5/CJ4 Hopane values below 1 and varIable Pr/Ph (from 1 to 5), IndIcatIng that these extracts were generated from sIlIcIclastIc rocks deposIted In shelf marIne and marIne deltaIc envIronments. (FIgure C).LECEN0ABCCHAPUNGO SEQUENCECHMBORAZO Fm.OL SEEPUNKNOWNPEA MORADA Fm.0.1110100Phytane / nC180.1 110100P r i s t a n e / n C1 7Bi odegradationMaturityOxidixingReducingTerrestrialTypeKerogenTypeKerogenAlgal,ReducingEnvironmentMixedKerogen-012345Pristane / Phytane00.20.40.60.8 1O I e a n a n e / C3 0H o p a n eMarine Deltaic(CENOZOC)Shelf MarineMarine Deltaic(CRETACEOUS)012345Pristane / Phytane00.5 11.5 22.5 3C3 5/ C3 4H o p a n eMarine CarbonaticShelf MarineMarine Deltaic0eposItIonaI EnvIronments The steranes ternary dIagram (C27, C28 and C29) shows that the rock extracts from the ChImborazo and Pea |orada formatIons have a hIgher proportIon of C27 steranes, IndIcatIve of more marIne organIc matter Input, and extracts from the Chapungo sequence have a hIgher proportIon of C29 steranes IndIcatIve of more terrestrIal organIc matter Input. n summary, rock extracts from the Paleocene ChImborazo FormatIon are characterIzed by showIng PrIstane/Phytane 2.0, CJ5/CJ4 hopanes 1.0, and Dleanane/CJ0 Hopane 0.2 and predomInance of C27/C29. ndIcatIve of rocks deposIted under marIne deltaIc condItIons wIth terrIgenous Input. Pock extracts from the Paleocene Pea |orada formatIon and Cretaceous Chapungo sequence are characterIzed by showIng PrIstane/Phytane 2.0, CJ5/CJ4 hopanes 1.0, and Dleanane/CJ0 Hopane 0.2. ndIcatIve of rocks deposIted under marIne condItIons wIth low terrIgenous Input.35DPCANIC CEDCHEhISTPY ATLAS DF CDLDhIACAUCA - PATA ASINLECEN0CHMBORAZO Fm.PEA MORADA Fm.CHAPUNGO SEQUENCEUNKNOWN050100100500100500%C29%C27%C28DPCANIC CEDCHEhISTPY ATLAS DF CDLDhIASource Pock CharacterIzatIonCAUCA- PATA ASIN36 The data obtaIned from pyrolysIs of outcrop samples (FIgure A). The Dxygen ndex vs Hydrogen ndex dIagram (7an Krevelen dIagram) shows that rock samples from the Cretaceous Chapungo Sequence and CenozoIc ChImborazo, CuachInte, |osquera and EsmIta formatIons have type oIlprone kerogen. There are also samples from these formatIons wIth type gasprone characterIstIcs along wIth samples of the CenozoIc CInta de PIedra, Pea |orada and FerreIra formatIons (FIgure 8). for Hydrogen ndex (H) and S2 peak, IndIcate that most of the samples collected In the basIn have poor generatIon potentIal (H 200mg HC/g TDC and S2 5 mg HC/g rock) however samples wIth good generatIon potentIal (H 200mg HC/g TDC and S2 5 mg HC/g rock) were obtaIned from the Cretaceous Chapungo Sequence, and from the CenozoIc ChImborazo, CuachInte, |osquera and EsmIta formatIons The Tmax maturIty parameter vs Hydrogen ndex graph shows that many samples from the Cretaceous to CenozoIc unIts mentIoned are mature to overmature In the basIn (FIgure C). There Is no clear correlatIon between stratIgraphIc posItIon and thermal maturIty, because younger and older rocks have sImIlar maturItIes, whIch suggests that there Is some process In the basIn affectIng In the same way the whole stratIgraphIc sequence, possIbly related to the extensIve presence of IntrusIve rocks In the basIn. LECEN0ABC0102030405060708090100S2 (mg HC / gROCK)0100200300400500600H y d r o g e n I n d e x ( m g H C / g T O C )Poor Generation Potential and/or High thermal maturityExcellent Generation Potential Low thermal maturityAGUA CLARA Fm.CHMBORAZO Fm.DABASCO Gr.MOSQUERA Fm.PEA MORADA Fm.RO GUABAS SECTONCHAPUNGO SEQUENCEUNKNOWNCNTA DE PEDRA Fm.ESMTA Fm.FERRERA Fm.GUACHNTE Fm.050100150200250300Oxygen Index (mg CO2 / gTOC)0100200300400500600H y d r o g e n I n d e x ( m g H C / g T O C )V370390410430450470490510530550Tmax (oC)0200400600H y d r o g e n I n d e x ( m g H C / g T O C )IIIIII1.35%Ro0 . 5 % R oImmatureMatureOvermatureSource Pock CharacterIzatIon37DPCANIC CEDCHEhISTPY ATLAS DF CDLDhIACAUCA - PATA ASIN DrganIc content (TDC) and S2 peak values IndIcate source rock oIl generatIon potentIal, thIs graph shows that there are samples from Cretaceous (Chapungo sequence) and CenozoIc unIts (|osquera, FerreIra, and EsmIta formatIons) (FIgure A).The vItrInIte reflectance (Po) InformatIon shows that most of the samples are Immature or close to early maturIty In the basIn. However some samples are In the oIl generatIon wIndow and even overmature In accordance wIth Tmax data. n thIs graph It Is Important to notIce that due to the fact that the samples were taken from outcrops, the depth Is a relatIve depth correspondIng to the stratIgraphIc posItIon of the samples In the fIeld column and not burIal depths (FIgure 8). n summary, the best source rocks at the basIn, wIth good to excellent oIl generatIon potentIal Intervals are the Cretaceous rocks of the Chapungo Sequence and the CenozoIc rocks of the |osquera, FerreIra and EsmIta formatIons. |aturIty data from outcrop samples IndIcate that the oIlprone formatIons are mature for hydrocarbons generatIon, and that good qualIty oIls could be expected from the hIgh thermal maturIty reached by some potentIal source rocks In the basIn.wIth good to excellent oIl generatIon potentIal (S2 up to 50 mg HC/g rock and TDC up to 9). AddItIonally thIs graph shows that samples from the Cretaceous Pio Cuabas FormatIon and CenozoIc |osquera and CInta de PIedra formatIons, although have good to excellent TDC values (up to 10 wt), do not have good S2 values ( 5 mg HC/g rock), IndIcatIng that the kerogen In these formatIons Is not labIle and approprIate for lIquId hydrocarbons generatIon LECEN0ABAGUA CLARA Fm.CHMBORAZO Fm.DABASCO Gr.MOSQUERA Fm.PEA MORADA Fm.RO GUABAS SECTONCHAPUNGO SEQUENCEUNKNOWNCNTA DE PEDRA Fm.ESMTA Fm.FERRERA Fm.GUACHNTE Fm.0246810%TOC010203040S 2 ( m g H C / g R O C K )ExcellentVery GoodGoodFairPoor0.1110%Ro120001100010000900080007000600050004000300020001000 0D e p t h ( F e e t )ImmatureOvermature(Gas Window)O i I W i n d o wDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIACAUCA- PATA ASINSurface CeochemIstry ComposItIonal data from surface geochemIstry samples IndIcate that most of the hydrocarbons In the basIn are thermogenIc, formed maInly durIng oIl generatIon wIndow wIth mInor presence of hIgh maturIty hydrocarbons (gas generatIon wIndow). (FIgure A). sotopIc data from these type of samples IndIcate thermogenIc orIgIn of the gases wIth mIxIng between dIfferent thermal maturIty hydrocarbons, generatIon from type and kerogens, and to a mInor extent mIcrobIal oxIdatIon (FIgure 8).There are very few samples of mIcrobIal gas to consIder bIogenIc gas an Important process In the basIn.38LECEN0AB0123450.51.52.53.54.5C2/(C3+C4)1101001000C1/ ( C2+ C3)MicrobiaI gasDry gasMixed deep gasCondensateMixedOiIUNKNOWN-100-90-80-70-60-50-40-30-20-95-85-75-65-55-45-35-25

13C Methane (o/oo)110100100010000100000C 1 / ( C 2 + C 3 )BacterialPredominantly methyltype fermentationPredominantlyCO2 reductionMicrobialoxidationMixedType KerogenType KerogenThermogenicCESAP PANCHEPIA ASINCeneraIItIesWeIIs and SeepsSource Pock CharacterIzatIonSource Pock uaIIty and haturIty hapsSurface CeochemIstry DPCANIC CEDCHEhISTPY ATLAS DF CDLDhIACESAP PANCHEPIA ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIASCHEMATC CROSS SECTONCESAR - RANCHERA BASNWEBasementCretaceousCenozoicUpper CretaceousColor code according to the commission for the Geological Map of the World (2005)01234secTimeCESAR RANCHERA BASN LOCATON AND BOUNDARESPacific OceanCaribbean SeaVENEZUELABRASLPERUECUADORPANAMACOLOMBABOUNDARESSW: Bucaramanga-Santa Marta Fault (B.S.M.F) E-SE: Pre-Cretaceous rocks of the de Perij (22); Colombian-Venezuelan boundary.SerranaNE: Oca Fault (O.F.)NW: Pre-Cretaceous rocks of the Sierra Nevada de Santa Marta (23) Caribbean SeaRiohachaSanta MartaBarranquillaValledupar2205VENEZUELAB.S.M.F72717374759101112727173747591011122322P A L E O G E N E N E O G E N ERESERVOIRS O U R C ELITHOLOGYT R A PRANCHERIACESARCRCR????????STRAT. UNITSCESARRANCHERIASTRAT. UNITSGENERATIONMIGRATIONLa JaguaBarco Fm.Delicias Fm.Molino Fm.Laja/La LunaAguas BlancasLagunitas Fm.Ro negro Fm.La Quinta Fm.Cachiri Gp.VolcanoclasticsCerrejn Fm.Manantial Fm.Hato NuevoManaure Fm.Laja/La LunaAguas BlancasLagunitas Fm.Ro negro Fm.La Quinta Fm.Cachiri Gp.Palmito Sh.Tabaco Ss.Conjunto CalcreoConjunto ConglomerticoC R E T A C E O U SJ U R A .HIATUSHIATUSLimestonesSandstonesShalesConglomeratesCoalsCeneraIItIesThe source rock geochemIcal InformatIon Interpreted for the Cesar Pancheria 8asIn Includes TDC and PockEval PyrolysIs data from 417 samples taken In 4 wells and 81 samples from outcrops; addItIonally 91 organIc petrography samples from 4 wells and 62 samples from outcrops, and 417 surface geochemIstry samples were also Interpreted.0ue to the lack of crude oIl geochemIcal data, crude oIl InterpretatIon can not be made for the basIn.40From Barrero et al., 2007From Barrero et al., 2007From Barrero et al., 2007WeIIs and SeepsThe number of wells and/or surface locatIons wIth geochemIcal InformatIon In the Cesar Pancheria 8asIn Is 18.CESAP-PANCHEPIA ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIA41VALLEDUPAR10200001040000106000010800001100000112000011400001160000118000015200001540000156000015800001600000162000016400001660000168000017000001720000CERREJON-1CESAR A-1XCesar F-1XCESAR H-1XCH31COMPAE-1EL MOLINO-1EL PASO-1EL PASO-2EL PASO-3EL PASO-4LOS VENADOS-1M75MM194MOLINO 1-XMS63PAPAYAL-1RIO MARACAS-102550Kms|ap datum: |agna SIrgasCoord. orIgIn: 8ogotWells wIth geochemIcal InformatIonDIl seepsCItIes/TownsFONSECALA JAGUADE BRCOCESAP PANCHEPIA ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIASource Pock CharacterIzatIonLECEN042ABC The data obtaIned from pyrolysIs of rock samples (FIgure A). The Dxygen ndex vs Hydrogen ndex dIagram (7an Krevelen dIagram) shows that rock samples from the Cretaceous LagunItas, Aguas 8lancas, La Luna and |olIno formatIons have type oIlprone kerogen. The CenozoIc Los Cuervos FormatIon also has type kerogen, but there are samples from thIs formatIon and the Cretaceous |olIno FormatIon wIth type gasprone kerogen In the basIn. (FIgure 8). for Hydrogen ndex (H) and S2 peak, IndIcate that samples from the Cretaceous Aguas 8lancas, La Luna and |olIno formatIons and the CenozoIc Los Cuervos FormatIons have good generatIon potentIal (H 200mg HC/g TDC and S2 5 mg HC/g rock).The Tmax maturIty parameter vs Hydrogen ndex graph shows that many samples from the Cretaceous to CenozoIc unIts mentIoned, have reached early maturIty overmature condItIons In the basIn. |aturIty Increases wIth burIal depth beIng the Early Cretaceous rocks (Pio Negro, LagunItas and Aguas 8lancas formatIons) more mature, wIth samples of the LagunItas, La Luna and |olIno formatIons at the oIl generatIon peak (FIgure C).AGUAS BLANCAS Fm.LA LUNA Fm.LAGUNTAS Fm.MOLNO Fm.RO NEGRO Fm.UNKNOWNLA QUNTA Fm.LOS CUERVOS Fm.010203040S2 (mgHC / gROCK)0100200300400500600H y d r o g e n I n d e x ( m g H C / g T O C )Poor Generation Potential and/or High thermal maturityExcellent Generation Potential Low thermal maturity050100150200250300Oxygen Index (mg CO2 / gTOC)0100200300400500H y d r o g e n I n d e x ( m g H C / g T O C )V370390410430450470490510530550Tmax (oC)0200400600H y d r o g e n I n d e x ( m g H C / g T O C )IIIIII1.35%Ro0 . 5 % R oImmatureMatureOvermatureSource Pock CharacterIzatIonLECEN0LECEN043CESAP-PANCHEPIA ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIAAB DrganIc content (TDC) and S2 peak values IndIcate source rock oIl generatIon potentIal, thIs graph shows that there are samples from Cretaceous (LagunItas, Aguas 8lancas, La Luna, and |olIno formatIons ) and CenozoIc unIts (Los Cuervos FormatIon) (FIgure A).The vItrInIte reflectance (Po) InformatIon shows that many samples In the basIn are mature or overmature at the Cesar A1X and Compae1 well locatIons to the south of the basIn, and less mature at the El |olIno1X and El PasoJ wells to the north. (FIgure 8). n summary, the best source rocks at the basIn, wIth good to excellent oIl generatIon potentIal Intervals are the Cretaceous rocks of the LagunItas,Aguas 8lancas, La Luna and |olIno formatIons and the CenozoIc rocks of the Los Cuervos formatIon. |aturIty data IndIcate that the oIlprone formatIons are mature for hydrocarbons generatIon, and that good qualIty oIls could be expected from the hIgh thermal maturIty reached by potentIal source rocks In the basIn.wIth good to excellent oIl generatIon potentIal (S2 up to 50 mg HC/g rock and TDC up to 9). AddItIonally thIs graph shows that samples from the Cretaceous LagunItas FormatIon and CenozoIc Los Cuervos FormatIon, although have good to excellent TDC values (up to 10 wt), do not have good S2 values ( 5 mg HC/g rock), IndIcatIng that the kerogen In these formatIons Is not labIle and approprIate for lIquId hydrocarbons generatIon AGUAS BLANCAS Fm.LA LUNA Fm.LAGUNTAS Fm.MOLNO Fm.RO NEGRO Fm.UNKNOWNLA QUNTA Fm.LOS CUERVOS Fm.0246810%TOC010203040S 2 ( m g H C / g R O C K )ExcellentVery GoodGoodFairPoorCESAR A-1XCOMPAE-1EL MOLNO-1XEL PASO-30.1110%Ro120001100010000900080007000600050004000300020001000 0D e p t h ( F e e t )ImmatureOvermature(Gas Window)O i I W i n d o wCESAP PANCHEPIA ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIASource Pock uaIIty and haturIty haps7ItrInIte Peflectance (Po)Hydrogen ndexLa Luna FormatIon10200001040000106000010800001100000112000011400001160000118000015200001540000156000015800001600000162000016400001660000168000017000001720000COMPAE-1EL MOLNO-1X 0.46% Ro to 0.61% Ro 0.61% Ro to 0.75% Ro10200001040000106000010800001100000112000011400001160000118000015200001540000156000015800001600000162000016400001660000168000017000001720000COMPAE-1253mg HC/g TOC44|ap datum: |agna SIrgasCoord. orIgIn: 8ogotSource Pock uaIIty and haturIty hapsDrganIc |atter Content (TDC)La Luna FormatIon10200001040000106000010800001100000112000011400001160000118000015200001540000156000015800001600000162000016400001660000168000017000001720000CH31M75MM194MS63COMPAE-10% wt1% wt2% wt3% wt4% wt45CESAP-PANCHEPIA ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIA|ap datum: |agna SIrgasCoord. orIgIn: 8ogotCESAP PANCHEPIA ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIALECEN0Surface CeochemIstry ComposItIonal data from surface geochemIstry samples IndIcate that hydrocarbons are thermogenIc, formed maInly durIng late oIl generatIon wIndow (condensates) wIth mInor presence of hIgh maturIty hydrocarbons (gas generatIon wIndow) wIth some mIxIng between dIfferent thermal maturIty hydrocarbons. sotopIc data IndIcates thermogenIc generatIon from probably type and type kerogensThere Is no evIdence of mIcrobIal gas In the basIn.46ABUNKNOWN0123450.51.52.53.54.5C2/(C3+C4)1101001000C1/ ( C2+ C3)MicrobiaI gasDry gasMixed deep gasCondensateMixedOiI-100-90-80-70-60-50-40-30-20-95-85-75-65-55-45-35-25

13C Methane (o/oo)110100100010000100000C 1 / ( C 2 + C 3 )BacterialPredominantly methyltype fermentationPredominantlyCO2 reductionMicrobialoxidationMixedType KerogenType KerogenThermogenicCHDCD ASINCeneraIItIesWeIIs and SeepsSource Pock CharacterIzatIonSurface CeochemIstry DPCANIC CEDCHEhISTPY ATLAS DF CDLDhIACHDCD ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIACeneraIItIes48WESCHEMATC CROSS SECTONCHOCO BASNOceanic CrustPaleoceneNeogeneColor code according to the commission for the Geological Map of the World (2005)sec0123Pacific OceanCaribbean SeaVENEZUELABRAZLPERUECUADORPANAMACOLOMBACHOC BASN LOCATON AND BOUNDARESBOUNDARESN-NW: Geographic border of Panam South: Garrapatas fault zone (G.F.Z.) NW: Serrana de Baud (SB) SW: Present Pacific coastline East: Cretaceous rocks of the Western Cordillera (WC) and partially the Murind fault (M.F.) Mande quartzdiorite (M.B.), the PANAMA06MedellinbaguPacific OceanU.F.S..Z..FG345757677797880678757677797880345678SBM.B.WCM.F.QuibdThe source rock geochemIcal InformatIon Interpreted for the Choco 8asIn Includes TDC and PockEval PyrolysIs data from 168 samples taken In 2 locatIons; addItIonally 68 organIc petrography samples from 2 locatIons, and JJJ surface geochemIstry samples were Interpreted. 0ue to the lack of crude oIl geochemIcal data, crude oIl InterpretatIon was not made for the basIn.From Barrero et al., 2007From Barrero et al., 2007From Mojica et al.,, 2010U2 S 0 0V U N G U l U O4 S 0 0S 0 04 2 0 0B A N J U A NC O N G L .L A V O J A P P Al B 1 V l N AB l L P P AO L l Gl P O1 0 0 0C O N U O 1 O2 . S - S - A v L P A G L 2 . 7 S2 - 8 - A v L P A G L S . SC A N A B G O P U A BL A L O U l BB 1 A . C L C l L l A??P L P l O UG P O U P| O P V A 1 l O NLl1HOLOGYU1 H l C K N L B B ( m }1 O CB C lP L 1 P O L L U VB Y B 1 L VBANUB1ONLBP L l O C L N LP L L l B 1 O C L N L2 S 0 0V U N G U l U OU P P L P V l O C L N L4 S 0 0S 0 04 2 0 0B A N J U A NL O W L P V l O C L N LC O N G L .L A V O J A P P Al B 1 V l N AB l L P P AO L l Gl P OP A L L O C L N L - L O C L N LA 1 P A 1 O1 0 0 0C O N U O 1 OCONGLOVLPA1LB0 . 2 S 7 - 0 . 7 0 7 - A v L P A G L : 0 . S 7 70 . 2 2 7 - 1 2 . 6 7 - A v L P A G L : 2 . 8 7C P L 1 A C L O U BC A N A B G O P U A BL A L O U l BB 1 A . C L C l L l A??V A N U L B A 1 H O L l 1 HLlVLB1ONLB,VUUPOCKB,CHLP1B.BlL1B1ONLBANULl1HlCBANUB1ONLBUAPKVUUB1ONLB,VAPLBANUCHLP1B.UlABABLB,BABAL1BANUBABlC1U||B,Wl1HUl||LPLN1BLUlVLN1APYBLUBBANUB1ONLBlN1LPBLUULUWl1HVUUB1ONLB.LlVLB1ONLBANUVUUB1ONLBlN1LPBLUULUWl1HlVPUPLBANUB1ONLB.BlL1B1ONLBANUCLAYB1ONLBWl1HBLUBO|CONGLOVLPA1LBANUBANUB1ONLB.CONGLOVLPA1LBCLAYB1ONLBLlVLB1ONLBBANUB1ONLB,CONGLOVLPA1lCBANUB1ONLBANUBlL1B1ONLB.BABALCONGLOVLPA1L,BANUB1ONLBANUVUUB1ONLB.LlVLB1ONLB,BANUB1ONLBANUVUUB1ONLB.LlVLB1ONLBANUVAPLBlN1LPBLUULUWl1HCHLP1ANUVUUB1ONLB.BANUB1ONLlN1LPCALA1lONBlN1HL1OP.Atrato Sub8asInSan Juan Sub8asInWeIIs and SeepsThe number of wells and/or surface locatIons wIth geochemIcal InformatIon In the Choco 8asIn Is 2.DIl seeps are maInly located at the southern and eastern parts of the basIn.CHDCD ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIA4QUBD60000065000070000075000095000010000001050000110000011500001200000125000013000001350000BUCHADO-102550Kms|ap datum: |agna SIrgasCoord. orIgIn: 8ogotWells wIth geochemIcal InformatIonDIl seepsCas seepsUndetermIned seepsCItIes/TownsPACIFICOCEANWESTERNCORDI LLERAPANAMBAHASOLANOTSMNAROSUCOCHDCD ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIASource Pock CharacterIzatIonLECEN050ABC The data obtaIned from pyrolysIs of rock samples l (FIgure A). The Dxygen ndex vs Hydrogen ndex dIagram (7an Krevelen dIagram) shows that rock samples from the Paleogene ro FormatIon have type and oIlprone kerogens. n the case of the Neogene tsmIna and Conglomerado de la |ojarra formatIons theIr samples are IndIcatIve of type gasprone kerogen to type 7 kerogen. (FIgure 8). for Hydrogen ndex (H) and S2 peak, IndIcate that samples from the Neogene tsmIna and Conglomerados de la |ojarra formatIons have poor generatIon potentIal (H 200mg HC/g TDC and S2 5 mg HC/g rock) but consIderIng the hIgh thermal maturIty reached accordIng to Tmax data, theIr present values could be evIdence of organIc content depletIon, and samples from the Paleogene ro FormatIon have good to excellent generatIon potentIal (H 200mg HC/g TDC and S2 5 mg HC/g rock). The Tmax maturIty parameter vs Hydrogen ndex graph shows that most samples from the CenozoIc unIts mentIoned, have reached early maturIty to overmature generatIon condItIons In the basIn, beIng the samples from the tsmIna FormatIon the most mature In the basIn, and thIs hIgh thermal maturIty reached by these rocks could cause depletIon In the organIc content, gIvIng low H and S2 values. ConsIderIng thIs, It Is very unlIkely that these samples represent the real generatIon potentIal of these formatIons In the basIn (FIgure C).0102030405060708090100S2 (mgHC / gROCK)0100200300400500600H y d r o g e n I n d e x ( m g H C / g T O C )Poor Generation Potential and/or High thermal maturityExcellent Generation Potential Low thermal maturityR Fm.UNKNOWNCONGLOMERADOSDE LA MOJARRA Fm.STMNA Fm.050100150200250300Oxygen Index (mg CO2 / gTOC)0100200300400500600700H y d r o g e n I n d e x ( m g H C / g T O C )V370390410430450470490510530550Tmax (oC)0200400600H y d r o g e n I n d e x ( m g H C / g T O C )IIIIII1.35%Ro0 . 5 % R oImmatureMatureOvermatureSource Pock CharacterIzatIon51CHDCD ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIAABLECEN0 DrganIc content (TDC) and S2 peak values IndIcate source rock oIl generatIon potentIal, thIs graph shows that there are samples from the ro FormatIon wIth good to excellent oIl generatIon potentIal (S2 up to 50 mg HC/g rock and TDC up to 9) (FIgure A). The Hydrogen ndex vs DrganIc content (TDC) graph shows that samples from the ro FormatIon have the best source rock characterIstIcs (H values J00 mg HC/g TDC and TDC 2), whIch are typIcal from rocks deposIted In shelf marIne envIronments. AgaIn the low H and TDC values for the samples of the tsmIna FormatIon could be affected by the hIgh thermal maturIty reached by thIs unIt, and the data could not be relIable to determIne the deposItIonal condItIons of the source rock(FIgure 8). n summary, the best source rock at the basIn, wIth good to excellent oIl generatIon potentIal Intervals Is the Paleogene ro FormatIon. However, the hIgh thermal maturIty reached by the Neogene tsmIna and Conglomerados de la |ojarra formatIons precludes dIscardIng these unIts as good oIl sources In the basIn. AddItIonally the thermal maturIty data suggests that all these unIts have reached maturIty for good qualIty hydrocarbons generatIon In the basIn.R Fm.UNKNOWNCONGLOMERADOSDE LA MOJARRA Fm.STMNA Fm.0246810%TOC01020304050607080S 2 ( m g H C / g R O C K )ExcellentVery GoodGoodFairPoor0246810121416%TOC0100200300400500600700800H y d r o g e n I n d e x ( m g H C / g T O C )Shelf Marine(Immature)ProximaI Marine to ContinentaI(Overmature)CHDCD ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIALECEN0Surface CeochemIstry ComposItIonal data from surface geochemIstry samples IndIcate that the hydrocarbons are thermogenIc, formed maInly durIng late oIl generatIon wIndow (condensates) wIth mInor presence of hIgh maturIty hydrocarbons (gas generatIon wIndow). |IxIng between dIfferent thermal maturIty hydrocarbons Is also IndIcated by the data.There are very few samples of mIcrobIal gas to consIder bIogenIc gas an Important process In the basIn.520123450.51.52.53.54.5C2/(C3+C4)1101001000C1/ ( C2+ C3)MicrobiaI gasDry gasMixed deep gasCondensateMixedOiIUNKNOWNEASTEPN CDP0ILLEPA ASINCeneraIItIesWeIIs and SeepsCrude DII uaIItySource Pock CharacterIzatIonSurface CeochemIstryPetroIeum Systems (Crude-Pock CorreIatIons) DPCANIC CEDCHEhISTPY ATLAS DF CDLDhIAEASTEPN CDP0ILLEPA ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIACeneraIItIesEASTERN CORDLLERA BASN LOCATON AND BOUNDARESPacific OceanCaribbean SeaVENEZUELABRAZLPERUECUADORPANAMACOLOMBAVENEZUELACucuta456787271737475767271737475763456783S.M.BOUNDARESNorth: gneous and metamorphic rocks from the Santander massif (S.M.) South: Algeciras-Garzn Fault System (A.G.F.S.) West: Bituima and La Salina Fault System (B.S.F.S.) East: frontal thrust system of the Eastern Cordillera B. S. F. S.Bucaramanga4VillavicencioYopalTunjaBogotA. G. F. S.10G. F. S.ConcentracionLenPicacho Fm.Los CuervosArc. de SochaEsmeraldas F.CENTRAL REGONLisama F.Fomeque Fm.Lutitas de MacanalChipaque Fm.Guaduas Fm.Umir Fm.La Luna F.Simiti Fm.Tablazo F.Paja Fm.Aren. de LasJuntasMirador Fm.Barco Fm.Une Fm.Los Santos Fm.Une Fm.Guadalupe Gp.LTHOLOGY-STRATGRAPHC UNTSWESTERNFOOTHLLSEASTERNFOOTHLLSLa Paz Fm.Picacho Fm.Aren. de SochaCarboneraRosablanca Fm.Ermitao Fm.Girn Fm.Girn Fm.Real Gp.Mugrosa F.Colorado F.Mainly conglomeratesMainly SandstonesShalesLimestonesGuayabo F.Mesa Fm.VV: VolcanoclasticsThe source rock geochemIcal InformatIonInterpreted for the Eastern CordIllera 8asInIncludes TDC and PockEval PyrolysIsdata from 1512 samples taken In 9 locatIons; addItIonally J69 organIc petrography samples from 8 locatIons were Interpreted.Crude oIl and extracts InformatIon from 4 bulkanalysIs samples, 111 lIquId chromatographysamples, 114 gas chromatography samples,125 bIomarker sample,42 Isotopesand J49 surface geochemIstry samples were also Interpreted.54From Barrero et al., 2007Albian-TuronianBerriasian-AptianJurassicBasementMiddleMiocene-RecentEocene-LowerMioceneUpperMaastrichtian-PaleoceneConiacian-LowerMaastrichtianG U A C A R A M OF A U L TARCABUCOANTCLNEP E S C AF A U L TC H A M E Z AF A U L TC U S A N AF A U L TS A L N A SF A U L TMDDLEMAGDALENAVALLEYSENW20km0Modified from Cooper et al., 1995From Barrero et al., 2007WeIIs and SeepsThe number of wells and/or surface locatIons wIth geochemIcal InformatIon In the Eastern CordIllera 8asIn Is 12 .DIlseeps are located wIdespread all over the basInEASTEPN CDP0ILLEPA ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIA55VLLAVCENCOBUCARAMANGATUNJAYOPAL900000950000100000010500001100000115000012000008000008500009000009500001000000105000011000001150000120000012500001300000ALPUJARRA-1APICALA-1BOLIVAR-1 (BOLIVAR FIELD)CHITASUGA-1CORMICHOQUE-1CORRALES-1SUESCA NORTE-1TAMAUKA-1VILLARRICA-102550KmsBOGOTWells wIth geochemIcal InformatIonDIl seepsCas seepsUndetermIned seepsCItIes/Towns|ap datum: |agna SIrgasCoord. orIgIn: 8ogotLLANOS BASINMIDDLE MAGDALENA BASINUPPERMAGDALENABASI NVENEZUELASANTANDER MASSIFEASTEPN CDP0ILLEPA ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIACrude DII uaIItyLECEN056ABC Heavy oIls wIth AP gravItIes below 20 and sulfur content above 1 are present In the basIn. There Is correlatIon between sulfur and AP gravIty, IndIcatIng that the hIgher the AP gravIty the lower the sulfur content and hence crude oIl qualIty (FIgure A). The sulfur content of the oIls Is above 1, and Its NI/7 ratIo below 1, suggestIng that they are produced from rocks deposIted In a marIne suboxIc to anoxIc envIronment (FIgure C). The few crude oIls reported In the basIn suggests that AP gravIty should Increase wIth depth and that hydrocarbons could be found relatIvely shallow In the basIn (FIgure 8).01020304050API Gravity0 1 2 3% S u I f u rMaturityPCACHO Fm.UNKNOWN051015202530354045505560API Gravity2000018000160001400012000100008000600040002000 0D e p t h ( F e e t )Biodegraded OilHeavy OiINormaI OiILight OiICondensates0123Ni / V0 1 2 3% S u I f u rAnoxic MarineLacustrine or ContinentaISource Pock CharacterIzatIonEASTEPN CDP0ILLEPA ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIA57 The data obtaIned from pyrolysIs PockEval of rock samples the depletIon effect caused by the hIgh thermal maturIty reached by these rocks In subthrust sheets (FIgure A). The Dxygen ndex vs Hydrogen ndex dIagram (7an Krevelen dIagram) shows that rock samples from the Cretaceous Caballos, Conejo, La Luna, 7Illeta and UmIr formatIons have type oIlprone kerogen. There are also samples from these formatIons wIth type gasprone characterIstIcs. n the case of the CenozoIc unIts (Cuaduas, ConcentracIon and 8ogot formatIons) theIr samples are IndIcatIve of type gasprone kerogen to type 7 kerogen. (FIgure 8). for Hydrogen ndex (H) and S2 peak, IndIcate that samples from the Cretaceous Caballos, Conejo, La Luna, 7Illeta, Cuadalupe, Los PInos and UmIr formatIons and the CenozoIc ArcIllas de Socha FormatIon have good generatIon potentIal (H 200mg HC/g TDC and S2 5 mg HC/g rock). t Is Important to consIder that these and other unIts wIth source rock characterIstIcs, are or were deeply burIed In the basIn by thrustIng, and the poor generatIon values obtaIned from many samples could reflectThe Tmax maturIty parameter vs Hydrogen ndex graph shows that many samples from the Cretaceous to CenozoIc unIts mentIoned, have reached early maturIty to overmature condItIons In the basIn. 8eIng the samples from the Cretaceous Fomeque, ChIpaque and HIlo formatIons the more mature In the basIn (FIgure C).LECEN0ABCBOGOTA Fm.CABALLOS Fm.CABALLOS-UNE Fm.CACHO Fm.CACHO_GUADUAS Fm.CALZAS DE TETUN Fm.CHPAQUE Fm.CHURUVTA Fm.CONCENTRACON Fm.CONEJO Fm.El DAMANTE Fm.HLO Fm.LA NAVETA Fm.SOCOTA Fm.TRNCHERAS Fm. FOMEQUE Fm.NEVADA Gr. GUADALUPE Fm.GUADUAS Fm.LA FRONTERA Fm.LA LUNA Fm.LOS PNOS Fm.MONSERRATE Fm.PCACHO Fm.PNZAMA Fm.PLAENERS Fm.SOCOTA SHALE Fm.TBASOSA Fm.TLATA Fm.UNE Fm.UNKNOWNVLLETA Fm.YAV Fm.A. TERNA Fm.Arc. DE SOCHA Fm.LDTA SUPEROR Fm.UMR Fm.010203040S2 (mg HC / gROCK)0100200300400500600H y d r o g e n I n d e x ( m g H C / g T O C )Poor Generation Potential and/or High thermal maturityExcellent Generation Potential Low thermal maturity050100150200250300Oxygen Index (mg CO2 / gTOC)0100200300400500600H y d r o g e n I n d e x ( m g H C / g T O C )V370390410430450470490510530550Tmax (oC)0200400600H y d r o g e n I n d e x ( m g H C / g T O C )IIIIII1.35%Ro0 . 5 % R oImmatureMatureOvermatureEASTEPN CDP0ILLEPA ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIASource Pock CharacterIzatIon58 DrganIc content (TDC) and S2 peak values IndIcate source rock oIl generatIon potentIal, thIs graph shows that there are samples from Cretaceous unIts (Caballos, 7Illeta, La Luna, and UmIr) and the CenozoIc ArcIllas de Socha FormatIon, wIth good to excellent oIl generatIon potentIal (S2 up to 50 mg HC/g rock and TDC up to 9) (FIgure A).The vItrInIte reflectance (Po) InformatIon shows that the sedImentary sequence Is mature to overmature In the basIn. WIth varIable maturIty trends caused probably by dIfferent burIal and thermal hIstorIes controlled by the structural development of the Eastern CordIllera (FIgure 8). n summary, the best source rocks at the basIn, wIth good to excellent oIl generatIon potentIal Intervals are the Cretaceous rocks of the formatIons and the CenozoIc ArcIllas de Socha FormatIon. Tmax maturIty data IndIcates that the Cretaceous oIlprone formatIons are mature and that the hIgh thermal maturIty reached by some source rocks, could produce crude oIl wIth better characterIstIcs than that already found, and depleted or exhausted some source rocks In the basIn.Caballos, Conejo, La Luna, 7Illeta and UmIrLECEN0LECEN0ABBOGOTA Fm.CABALLOS Fm.CABALLOS-UNE Fm.CACHO Fm.CACHO_GUADUAS Fm.CALZAS DE TETUN Fm.CHPAQUE Fm.CHURUVTA Fm.CONCENTRACON Fm.CONEJO Fm.El DAMANTE Fm.HLO Fm.LA NAVETA Fm.SOCOTA Fm.TRNCHERAS Fm. FOMEQUE Fm.NEVADA Gr. GUADALUPE Fm.GUADUAS Fm.LA FRONTERA Fm.LA LUNA Fm.LOS PNOS Fm.MONSERRATE Fm.PCACHO Fm.PNZAMA Fm.PLAENERS Fm.SOCOTA SHALE Fm.TBASOSA Fm.TLATA Fm.UNE Fm.UNKNOWNVLLETA Fm.YAV Fm.A. TERNA Fm.Arc. DE SOCHA Fm.LDTA SUPEROR Fm.UMR Fm.0246810%TOC010203040S 2 ( m g H C / g R O C K )ExcellentVery GoodGoodFairPoor0.1110%Ro120001100010000900080007000600050004000300020001000 0D e p t h ( F e e t )ImmatureOvermature(Gas Window)O i I W i n d o wUNKNOWNCHTASUGA-1CORMCHOQUE-1CORRALES-1SUESCA NORTE-1TAMAUKA-1VLLA RCA-1LECEN0Surface CeochemIstry ComposItIonal data from surface geochemIstry samples IndIcate that hydrocarbons are thermogenIc, formed maInly durIng oIl generatIon wIndow wIth mInor presence of hIgh maturIty hydrocarbons (gas generatIon wIndow). |IxIng between dIfferent thermal maturIty hydrocarbons Is also IndIcated by the data.There Is no evIdence of mIcrobIal gas In the basIn.EASTEPN CDP0ILLEPA ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIA50123450.51.52.53.54.5C2/(C3+C4)1101001000C1/ ( C2+ C3)MicrobiaI gasDry gasMixed deep gasCondensateMixedOiIUNKNOWNEASTEPN CDP0ILLEPA ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIAPetroIeum Systems (Crude-Pock CorreIatIons)Crude Pock correlatIons from samples at the basIn suggest the followIng: There Is no good correlatIon between the few crude and extracts data avaIlable for the basIn. The crude In the PIcacho FormatIon has hIgher C29 steranes concentratIon than the rock extracts from the Cuadalupe FormatIon, IndIcatIng more terrestrIal organIc matter Input (FIgure A). The CJ5/CJ4 Hopanes, Ts/(Ts+Tm) and dIasteranes/steranes IndIcate that the rock extracts correspond to poorclay rocks probably carbonatIc deposIted under low reducIng condItIons (FIgures 8 and C). ThIs lack of correlatIon precludes a better determInatIon of the actIve petroleum systems In the basIn, however the exIstence of hypothetIcal petroleum systems can be stated from exIstIng geochemIcal and geologIcal InformatIon as follows: Los PInos Cuadalupe (.), 7Illeta/La Luna Cuadalupe (.), ChIpaque |onserrate (.), TIbasosa Une (.).60LECEN0ABC024681012Diasteranes / Steranes0 1 2 3C 3 5 / C 3 4 H o p a n e R a t i oDECREASNG CLAY CONTENT (CARBONATES) OR HGH REDUCNG CONDTONS (ANOXC)NCREASNG CLAY CONTENT (SHALES) ORLOW REDUCNG CONDTONS (OXC)CRUDE- PCACHO Fm.ROCK- Arc. de Socha Fm.ROCK- GUADUAS Fm.ROCK- LOS PNOS Fm.ROCK- PLAENERS Fm.ROCK- GUADALUPE Fm.0246810Diasteranes / Steranes0 2 4 6T s / ( T s + T m )NCREASNG CLAY CONTENTDECRESNG CLAY CONTENT (CARBONATES)100908070605040302010001020304050607080901000102030405060708090100%C29 Steranes%C28 Steranes%C27 SteranesLACUSTRNETERRESTRALSUPERORPLANTSESTUARNESMARNEPLANKTONEASTEPN LLANDS ASINCeneraIItIesWeIIs and SeepsCrude DII uaIIty0eposItIonaI EnvIronmentsChromatographySource Pock CharacterIzatIonSource Pock uaIIty and haturIty hapsCas CharacterIzatIonSurface CeochemIstryPetroIeum Systems (Crude-Pock CorreIatIons) DPCANIC CEDCHEhISTPY ATLAS DF CDLDhIAEASTEPN LLANDS ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIACeneraIItIesSCHEMATC CROSS SECTON EASTERN LLANOS BASNNWSECambro-OrdovicianDevonianJurassicCarboniferousColor code according to the commission for the Geological Map of the World (2005)CretaceousPaleogeneNeogene5Km15001000500012m EASTERN LLANOS BASN LOCATON AND BOUNDARESPacific OceanCaribbean SeaVENEZUELABRAZLPERUECUADORPANAMACOLOMBABOUNDARESNorth: Geographic Border Venezuela South: Vaups Arch (VA), and Precambrian metamorphic rocks (PM) Serrana de la Macarena (SM), West: frontal thrust system of the Eastern Cordillera East: Guyana Shield Precambrian rocks (GS)San Josedel GuaviareVENEZUELABogot456783269687071727374BRAZL696870717273744567832SMYopalGSPM11VillavicencioG. F. S.VAMainly SandstonesMainly shalesThe source rock geochemIcal InformatIonInterpreted for the Eastern Llanos 8asInIncludes TDC and PockEval PyrolysIsdata from 2402 samples taken In 129 wells;addItIonally 1J26 organIc petrography samples from 1JJ wells were Interpreted. Crude oIl and extracts InformatIon from 620 bulk analysIs samples, 705 lIquId chromatography samples, 978 gas chromatography samples, 771 bIomarker samples, 271 Isotopes samples and 1767 surface geochemIstry samples were also Interpreted.62From Barrero et al., 2007From Barrero et al., 2007From Barrero et al., 2007WeIIs and SeepsThe number of wells and/or surface locatIons wIth geochemIcal InformatIon In the Eastern Llanos 8asIn Is J01.DIlseeps are located at the western and southern parts of the basIn.63EASTEPN LLANDS ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIAVLLAVCENCOSAN JOSE DEL GUAVAREPTO. NRDATUNJAYOPALARAUCA10000001100000120000013000001400000150000016000001700000800000900000100000011000001200000050100KmsBOGOTEASTERN CORDILLERAMACARENA RANGEVENEZUELACAO LIMONARAUCACAO GARZATRINIDADTOCARIACUPIAGUACUSIANALA GLORIASANTIAGOCAO DUYALA FLORAREMACHE SURRUBIALESVALDIVIA/ALMAGROAPIAYCASTILLACHICHIMENECARACARA|ap datum: |agna SIrgasCoord. orIgIn: 8ogotDIl and gas fIeldsWells wIth geochemIcal InformatIonDIl seepsCas seepsUndetermIned seepsCItIes/TownsEASTEPN LLANDS ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIACrude DII uaIIty64 Normal and lIght oIls wIth AP gravItIes rangIng from 10 to 50 and sulfur content between 0 and 2.5 are present In the basIn. There Is no straIght relatIonshIp between sulfur and AP gravIty, but oIls above 25 AP have sulfur values below 1, and oIls below 25 show sulfur content wIth values up to J. ThIs suggests that In the basIn there are oIls wIth dIfferent thermal maturItIes and/or dIfferent degrees of preservatIon (bIodegradatIon, water washIng, etc.), because crudes havIng sImIlar AP gravItIes have dIfferent sulfur contents, whIch mIght IndIcate that bIodegradatIon Is IncreasIng sulfur content and/or reducIng AP gravIty, or dIfferent source rocks, consIderIng that oIls sourced from shales usually have lower sulfur content than oIls from carbonates (FIgure A). The sulfur content of most crude oIls Is lower than 1, and Its NI/7 ratIo below 1, suggestIng that they are produced from rocks deposIted In a marIne suboxIc envIronment wIth some terrIgenous organIc matter Input (FIgure C). There Is no dIrect relatIonshIp between depth and crude oIl qualIty, IndIcatIng that sImIlar qualIty oIls can be found at dIfferent stratIgraphIc levels, probably related to vertIcal mIgratIon along faults. 8ut addItIonally there Is the fact that dIfferent AP gravIty oIls can be found at sImIlar depths, reflectIng dIfferent preservatIon (bIodegradatIon) and/or thermal maturItIes (FIgure 8).LECEN0ACBBARCO Fm.BARCO- LOS CUERVOS Fm.CARBONERA Fm.GACHETA Fm.GUADALUPE Fm.MRADOR Fm.UNE Fm.UNKNOWN01020304050API Gravity0 1 2 3% S u I f u rMaturity012Ni / V0 1 2 3% S u I f u rAnoxic MarineLacustrine or ContinentaI051015202530354045505560API Gravity2000018000160001400012000100008000600040002000 0D e p t h ( F e e t )Biodegraded OilHeavy OiINormaI OiILight OiICondensates0eposItIonaI EnvIronmentsEASTEPN LLANDS ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIA65 The Phytane/nC18 vs PrIstane/nC17 graph IndIcates that most of the oIls have orIgIn from terrestrIal organIc matter (Type kerogen) deposIted In an oxIdIzIng envIronment, and have suffered low bIodegradatIon. There are also some samples In the mIxed kerogen range, suggestIng a source wIth terrestrIal and marIne organIc matter (Type and kerogens) deposIted In more reducIng condItIons (FIgure A). The PrIstane/Phytane vs Dleanane/CJ0 Hopane (Dleanane ndex) graph shows that oIls have low oleanane Index values (0.2) and Pr/Ph values rangIng from 1 to 5, whIch IndIcates that these oIls are generated from source rocks deposIted In shelf marIne to marIne deltaIc envIronments. There are some samples wIth hIgher oleanane Index values (0.2) and sImIlar Pr/Ph values, IndIcatIng that these oIls were generated from source rocks deposIted In marIne deltaIc envIronments wIth Important terrestrIal organIc matter Input. The oleanane Index has been also used as an age IndIcator of the source rock, wIth hIgh oleanane values for oIls generated In CenozoIc rocks and low oleanane values In oIls from older rocks (FIgure 8). The PrIstane/Phytane vs CJ5/CJ4 Hopane (Homohopane Index) graph shows that oIl samples have Pr/Ph values 1 and CJ5/CJ4 Hopane 1, IndIcatIng that these oIls were generated from sIlIcIclastIc rocks deposIted In a shelf marIne to deltaIc envIronment. (FIgure C).LECEN0ABCBARCO Fm.CARBONERA Fm.CHPAQUE Fm.GACHETA Fm.GUADALUPE Fm.MACARENA Fm.MRADOR Fm.UNE Fm.UNKNOWN0.1110100Phytane / nC180.1 110100P r i s t a n e / n C1 70.450.60.60.54BiodegradationMaturityOxidixingReducingTerrestrialTypeKerogenTypeKerogenAlgal,ReducingEnvironmentMixedKerogen-012345Pristane / Phytane00.20.40.60.8 1O I e a n a n e / C3 0H o p a n eMarine Deltaic(CENOZOC)Shelf MarineMarine Deltaic(CRETACEOUS)012345Pristane / Phytane00.5 11.5 22.5 3C3 5/ C3 4H o p a n eMarine CarbonaticShelf MarineMarine DeltaicEASTEPN LLANDS ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIA0eposItIonaI EnvIronmentsLECEN0 The steranes ternary plot shows predomInance of C27 steranes over C29 steranes, whIch IndIcates that marIne organIc matter predomInates In the source rocks. n summary, the crude oIls In the basIn correspond predomInantly wIth generatIng facIes deposIted In sIlIcIclastIc envIronments rangIng from marIne to deltaIc wIth an Important terrestrIal organIc matter Input. Some of these source rocks were deposIted durIng the Cretaceous consIderIng theIr low oleanane Index values, but the hIgher Dleanane/CJ0 Hopane ratIos (0.2) along wIth hIgh PrIstane/Phytane ratIos In some samples, suggest the possIbIlIty of CenozoIc generatIng facIes deposIted In deltaIc marIne envIronments. These crude oIls are of good qualIty wIth AP gravItIes above 25 and sulfur content below 1 for most of them, and are well preserved (low bIodegradatIon). At the ApIay sector the oIls show mIxIng of carbonatIc marIne (CJ5/CJ4 1.0) and deltaIc marIne facIes (PrIstane/Phytane 1.0).66050100100500100500%C29%C28%C27UNKNOWNChromatographyWeII Cusiana -4min010203040506070pA0250500750100012501500NNNP r i s t a n eP h y t a n eN - C 2 0N - C 2 1N - C 2 2N - C 2 3N - C 2 4N - C 2 5N - C 2 6N - C 2 7N - C 2 8N - C 2 9N - C 3 0N - C 3 1N - C 3 2N - C 3 3N - C 3 4N - C 3 5N - C 3 6N - C 3 7N N - C 8- C 8N - C 9N - C 9N - C 1 0N - C 1 0N - C 1 1N - C 1 1N - C 1 2- C 1 2N - C 1 3- C 1 3N - C 1 4N - C 1 4N - C 1 5N - C 1 5N - C 1 6N - C 1 6N - C 1 7- C 1 7N - C 1 8N - C 1 8N - C 1 9N - C 1 9N - C 2 0N - C 2 1N - C 2 2N - C 2 3N - C 2 4N - C 2 5N - C 2 6N - C 2 7N - C 2 8N - C 2 9N - C 3 0N - C 3 1N - C 3 2N - C 3 3N - C 3 4N - C 3 5N - C 3 6N - C 3 7ChromatogramThe CusIana oIl does not show bIodegradatIon, abundant low molecular weIght paraffIns fractIon and hIgh dIasteranes abundance, IndIcatIve of hIgh thermal maturIty. The PrIstane/Phytane ratIo 1.0 and dIasteranes abundance are IndIcatIve of generatIon from a sIlIcIclastIc (shale) source rock.has an 25.0030.0035.0040.0045.0050.0055.0060.0065.0070.0075.0050001000015000Time-->AbundanceIon 191.20 (190.90 to 191.90): PALM-2.D25.0030.0035.0040.0045.0050.0055.0060.0065.0070.0075.001000200030004000Time-->AbundanceIon 217.00 (216.70 to 217.70): PALM-2.DTricycIicsHopanesDiasteranesFragmentogram m/z 191Fragmentogram m/z 21767EASTEPN LLANDS ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIAEASTEPN LLANDS ASINDPCANIC CEDCHEhISTPY ATLAS DF CDLDhIAChromatographyWeII La GIoria -8min010203040506070pA0100200300N - C 8N - C 9N - C 1 0N - C 1 1N - C 1 2N - C 1 3N - C 1 4N - C 1 5N - C 1 6N - C 1 7P r i s t a n eN - C 1 8P h y t a n eN - C 1 9N - C 2 0N - C 2 1N - C 2 2N - C 2 3N - C 2 4N - C 2 5N - C 2 6N - C 2 7N - C 2 8N - C 2 9N - C 3 0N - C 3 1N - C 3 2N - C 3 3N - C 3 4N - C 3 5N - C 3 6"Refreshing"ChromatogramThe oIl of La ClorIa8 well Is representatIve of an oIl group typIcal of the central part of the basIn, where bIodegradatIon processes have been IdentIfIed and most normal alkanes have been lost.t Is observed lIght oIl refreshIng from a second generatIon pulse that