1Neogene Gas Total Petroleum SystemmdashNeogene Nonassociated Gas Assessment Unit of the San Joaquin Basin Province

SummaryBoundaries Extent of Etchegoin Formation on

the north and east limit of struc-tural deformation or petroleum system on the west White Wolf Fault on the south topographic surface to base of Etchegoin Formation

Source Rocks Pliocene marine kerogen-rich mudstone of the Etchegoin and San Joaquin Formations

Reservoir Rocks Pliocene shallow-water marine sandstones of the Etchegoin and San Joaquin Formations and Pleistocene deltaic and nonmarine sandstone lenses of the Tulare Formation

Traps Elongate gentle domes and strati- graphic trapsMigration Locally from adjacent kerogen-rich

mudstone into sandstone lensesTiming Traps formed during Pliocene as gas was formingPrimary Fields Bowerbank Buttonwillow Coles

Levee North Coles Levee South Dudley Ridge Harvester Paloma Rio Bravo Semitropic Ten Sec-tion Trico Trico Northwest

Secondary Fields Canal Garrison City Los Lobos Semitropic Shafter Southeast Strand

Exploration Status Moderately explored (03 well per square mile and 23 percent of all sections have at least one explor-atory well)

Resource Potential Potential for undiscovered fields in subtle structural and stratigraphic traps

DescriptionThe Neogene Nonassociated Gas Assessment Unit (AU)

of the Neogene Total Petroleum System consists of nonassoci-ated gas accumulations in Pliocene marine and brackish-water sandstone located in the south and central San Joaquin Basin Province (Rudkin 1968) Traps consist mainly of stratigraphic lenses in low-relief elongate domes that trend northwest-south-east Reservoir rocks typically occur as sands that pinch out at shallow depths (1000 to 7500 feet) within the Etchegoin and San Joaquin Formations

Map boundaries of the assessment unit are shown in figures 221 and 222 this assessment unit replaces the Pliocene

Neogene Gas Total Petroleum SystemmdashNeogene Nonassociated Gas Assessment Unit of the San Joaquin Basin ProvinceBy Allegra Hosford Scheirer1 and Leslie B Magoon

ContentsSummary----------------------------------------------------------------------------------1Description--------------------------------------------------------------------------------1Source Rocks---------------------------------------------------------------------------- 2Maturation and Migration-------------------------------------------------------------- 2Reservoir Rocks------------------------------------------------------------------------- 2Traps and Seals------------------------------------------------------------------------- 2Exploration Status and Resource Potential------------------------------------------ 2 References Cited------------------------------------------------------------------------ 3Figures------------------------------------------------------------------------------------ 5Table-------------------------------------------------------------------------------------14Appendixes (pdf files)

Petroleum Systems and Geologic Assessment of Oil and Gas in the San Joaquin Basin Province California

Chapter 22

1Now at Department of Geological and Environmental Sciences Stanford University Braun Hall 450 Serra Mall Stanford Calif 94305 allegrasstanfordedu

2 Petroleum Systems and Geologic Assessment of Oil and Gas in the San Joaquin Basin Province California

Nonassociated Gas play 1001 (shown by purple line in fig 221) considered by the US Geological Survey (USGS) in its 1995 National Assessment (Beyer 1996) The AU is drawn to include all existing fields containing nonassociated gas accumu-lations in the Pliocene to Pleistocene section as was done in the 1995 assessment but it was greatly expanded to include adja-cent areas believed to contain similar source and reservoir rock relationships Stratigraphically the AU extends from the topo-graphic surface to the base of the Etchegoin Formation (figs 223 and 224) The boundaries of the AU explicitly exclude gas accumulations in Neogene rocks on the severely deformed west side of the basin and gas accumulations in underlying Miocene rocks these resources which primarily consist of a mixture of mostly thermogenic and some biogenic gas are included in two other assessment units Lillis and others (this volume chapter 10) discuss the geochemical characteristics of biogenic gas in the San Joaquin Basin Province

Primary fields in the assessment unit are defined as those containing hydrocarbon resources greater than the USGS minimum threshold for assessmentmdash3 billion cubic feet (BCF) of gas secondary fields contain smaller volumes of gas but con-stitute a significant show of hydrocarbons Although 12 fields meet the 3 BCF criterion for inclusion in the AU only 5 fields were considered at the time of assessment

Source RocksIn general source rock units for natural gas are difficult to

identify with confidence because the composition of natural gas is too simple to correlate with organic matter in the source rock and the carbon isotopic composition of biogenic methane from all source rocks is similar (generally less than -55 per mil Rice and Claypool 1981) Geochemical analysis of five gas samples identified as biogenic in origin reveals that gas within the AU contains low carbon dioxide and nitrogen (less than 05 and 03 percent respectively) and low d13C methane (ndash56 to ndash70 per mil) (Lillis and others this volume chapter 10) Thus nonas-sociated biogenic gas in the central and southern San Joaquin Basin is most likely produced from microbial decomposition of marine organic matter within thick Pliocene marine mudstone and claystone within the boundaries of the AU (fig 225)

Although Rock-Eval pyrolysis and organic carbon (TOC) data are lacking from organic intervals within the Pliocene section the San Joaquin Formation is the suspected source rock for the biogenic gas in the AU because about 85 percent of the gas in the AU by volume resides in sand lenses that pinch out stratigraphically against mud and claystone of the San Joaquin Formation

Maturation and Migration

From early Pliocene time both stratigraphic trap develop-ment and gas charge in this AU probably occurred at or about

the time of deposition of the reservoir rock Biogenic gas forms from organic matter at low temperatures by microbial action at the surface to a depth of few thousand feet (Rice and Claypool 1981) Typically this gas vents to the atmosphere but under certain conditions it becomes trapped in adjacent sand lenses that are sealed by mudstone and is buried to greater depths This burial improves seal integrity and increases the pressure of the entrapped gas setting the stage for a possible commercial accumulation In this AU from late Pliocene time low-relief anticlinal traps formed and regional up-to-the-northeast tilting occurred after burial had already compacted fine-grained cap-ping beds (Bartow 1991 Beyer 1996)

Reservoir RocksHydrocarbon reservoir rocks in this AU consist of Pliocene

shallow-water marine sandstones of the Etchegoin and San Joaquin Formations that generally unconformably overlie upper Miocene rocks these are overlain by Pleistocene deltaic and nonmarine sand in the Tulare Formation (figs 224 and 225) Quaternary nonmarine deposits overlie the Tulare Formation Individual reservoir rocks range from about 5 to 30 feet thick (CDOGGR 1998) Porosities of these poorly compacted res-ervoir rocks are reported to range from about 20 to 35 percent (CDOGGR 1998) Detailed depositional histories of these reservoir rocks are discussed by Miller (1999) Reid (1995) and Loomis (1988) among others

Traps and SealsTraps of known biogenic gas accumulations are mostly

lenses of sandstone encased in a seal rock associated with elon-gate gentle domes Seal rocks are fine-grained low-permeability claystone mudstone and tightly cemented sandstone Depths of the 18 discovered accumulations range from about 1000 to 7500 feet with one accumulation at about 1000 feet deep (Dudley Ridge field) and two at about 7500 feet deep (Semi-tropic and Ten Section fields)

Exploration Status and Resource Potential

The AU has been intensely drilled by 1694 exploratory wells throughout its geographic extent except for a handful of townships where only a few wells exist (fig 222) However we believe the number of wells in the AU overstate its explora-tion maturity because these wells were drilled at times when natural gas wasnrsquot economic to produce industry likely drilled for deeper oil targets bypassing shallower gas sands Although most of the obvious structures have been drilled in the AU it seems likely that additional gas deposits in small sand stringers like the ones at Buttonwillow field (fig 226) exist Future dis-

3Neogene Gas Total Petroleum SystemmdashNeogene Nonassociated Gas Assessment Unit of the San Joaquin Basin Province

coveries of stratigraphically trapped biogenic gas likely reside in thin sand lenses that may have already been drilled through on the gentle east flank of the basin away from already-identified structures to the west There may also be additional biogenic gas in the Etchegoin and San Joaquin Formations above existing oil fields of the San Joaquin Basin about half of the gas accumula-tions assigned to this assessment unit are associated with deeper prolific oil pools

Undiscovered gas composition probably is similar to that of discovered gas which generally is 97 percent or more methane with average heating value of about 1015 BTUCFG Depths of undiscovered accumulations are most likely in the range of discovered reservoirs (1000 to 7000 feet) Undiscov-ered gas accumulations may exist in stratigraphic traps similar to those already discovered primarily in the erratic sands in the Mya sand zone of Berryman (1973) of the San Joaquin Forma-tion To find these a thorough understanding of reservoir sands and depositional systems combined with three-dimensional seismic surveys is essential

The 12 primary fields larger than 3 BCF and the 5 used in this assessment within the Neogene Nonassociated Gas Assess-ment Unit in order of decreasing gas volume are shown in table 221 and figure 228 all 18 gas fields are shown in figure 222 Trico field (fig 227) accounts for about 50 percent or 200 billion cubic feet (BCF) of the total biogenic gas produced in the San Joaquin Basin The remaining population of accu-mulations ranges from a few to tens of BCF in size Thus an additional 200 BCF accumulation is probably unlikely

All assessment results and supporting documentation for the Neogene Nonassociated Gas Assessment Unit of the San Joaquin Basin Province are available in files c100501pdf (data form for conventional assessment unit) d100501pdf (summary of discovery history) em100501pdf (probabilistic estimates) g100501pdf (graphs of exploration and discovery data for grown volumes) and k100501pdf (graphs of exploration and discovery data for known volumes) Klett and Le (this volume chapter 28) summarize the contents of these files Using five known accumulations the November 2003 assessment team estimated that the number of undiscovered accumulations greater than 3 BCF ranges from one to seven with the likeli-est number similar to the number of discovered accumulations The total estimated gas resource in this assessment unit thus ranges from 4 to 88 BCF with a mean of 29 BCF

Since the 2003 assessment the authors have determined that 12 known accumulations listed in table 221 should have been assigned to the AU Thus the discovery history of gas accumulations as illustrated in files d100501pdf g100501pdf and k100501pdf shows fewer accumulations of biogenic gas in the AU

References CitedAtwill ER 1935 Oligocene Tumey Formation of California

Bulletin of the American Association of Petroleum

Geologists v 19 no 8 p 1192-1204Bartow JA 1991 The Cenozoic evolution of the San Joaquin

Valley California US Geological Survey Professional Paper 1501 40 p

Berryman WM 1973 Lithologic characteristics of Pliocene rocks cored at Elk Hills Kern County California US Geological Survey Bulletin 1332-D 56 p

Beyer LA 1996 San Joaquin Basin Province in Gautier DL Dolton GL Takahashi KI and Varnes KL eds 1995 National assessment of United States oil and gas resourcesmdashResults methodology and supporting data US Geological Survey Digital Data Series DDS-30 release 2

Bishop CC 1970 Upper Cretaceous stratigraphy on the west side of the Northern San Joaquin Valley Stanislaus and San Joaquin counties California California Division of Mines and Geology Special Report 104 29 p

Callaway DC 1964 Distribution of uppermost Cretaceous sands in the Sacramento-Northern San Joaquin Basin of California Selected Papers Presented to San Joaquin Geological Society v 2 p 5-18

CDOGGR 1998 California oil and gas fields Sacramento Calif California Department of Conservation Division of Oil Gas and Geothermal Resources Publication No CD-1 1472 p

CDOGGR 2003 2002 Annual Report of the State Oil and Gas Supervisor California Department of Conservation Division of Oil Gas and Geothermal Resources Publication No PR06 263 p [also available at ftpftpconsrvcagovpuboilannual_reports2002]

Eckis R 1940 The Stevens sand southern San Joaquin Valley California [abs] Bulletin of the American Association of Petroleum Geologists v 24 no 12 p 2195-2196

Edwards EC 1943 Kern Front area of the Kern River oil field in Jenkins OP ed Geologic formations and economic development of the oil and gas fields of California San Francisco Calif State of California Department of Natural Resources Division of Mines Bulletin No 118 p 571-574

Goudkoff PP 1943 Correlation of oil field formations on west side of San Joaquin Valley in Jenkins OP ed Geologic formations and economic development of the oil and gas fields of California San Francisco Calif State of California Department of Natural Resources Division of Mines Bulletin No 118 p 247-252

Graham SA and Williams LA 1985 Tectonic depositional and diagenetic history of Monterey Formation (Miocene) central San Joaquin Basin California American Association of Petroleum Geologists Bulletin v 69 no 3 p 385-411

Hoffman RD 1964 Geology of the northern San Joaquin Valley Selected Papers Presented to San Joaquin Geological Society v 2 p 30-45

Kaplow EJ 1940 Gas fields of the southern San Joaquin Valley in Summary of operations California

4 Petroleum Systems and Geologic Assessment of Oil and Gas in the San Joaquin Basin Province California

oil fields San Francisco Calif Annual Report of the State Oil and Gas Supervisor v 24 no 1 p 30-50 [also available in California Division of Oil and Gas Summary of Operations 1915-1999 California Division of Conservation Division of Oil Gas and Geothermal Resources Publication No CD-3 and at ftpftpconsrvcagovpuboilSummary_of_Operations1938]

Kasline FE 1942 Edison oil field in Summary of operations California oil fields San Francisco Calif Annual Report of the State Oil and Gas Supervisor v 26 p 12-18 [also available in California Division of Oil and Gas Summary of Operations 1915-1999 California Division of Conservation Division of Oil Gas and Geothermal Resources Publication No CD-3 and at ftpftpconsrvcagovpuboilSummary_of_Operations1940]

Loken KP 1959 Gill Ranch gas field in Summary of operations California oil fields San Francisco Calif Annual Report of the State Oil and Gas Supervisor v 45 no 1 p 27-32 [also available in California Division of Oil and Gas Summary of Operations 1915-1999 California Division of Conservation Division of Oil Gas and Geothermal Resources Publication No CD-3 and at ftpftpconsrvcagovpuboilSummary_of Operations 1959]

Loomis KB 1988 Paleoenvironmental and paleoclimatic interpretation of upper Miocene-Pliocene lithofacies and macrobiota of the Etchegoin Group Jacalitos Canyon San Joaquin Valley California in Graham SA and Olson HC eds Studies of the geology of the San Joaquin Basin Los Angeles Pacific Section Society of Economic Paleontologists and Mineralogists book 60 p 303-318

McMasters JH 1948 Oceanic sand [abs] Bulletin of the American Association of Petroleum Geologists v 32 no 12 p 2320

Miller DD 1999 Sequence stratigraphy and controls on deposition of the upper Cenozoic Tulare Formation San Joaquin Valley California Stanford Calif Stanford University PhD dissertation 179 p

Miller RH and Bloom CV 1939 Mountain View oil field in Summary of operations California oil fields San

Francisco Calif Annual Report of the State Oil and Gas Supervisor v 22 no 4 p 5-36 [also available in California Division of Oil and Gas Summary of Operations 1915-1999 California Division of Conservation Division of Oil Gas and Geothermal Resources Publication No CD-3 and at ftpftpconsrvcagovpuboilSummary_of_Operations1937]

Noble EB 1940 Rio Bravo oil field Kern County California Bulletin of the American Association of Petroleum Geologists v 24 no 7 p 1330-1333

Reid SA 1995 Miocene and Pliocene depositional systems of the southern San Joaquin basin and formation of sandstone reservoirs in the Elk Hills area California in Fritsche AE ed Cenozoic paleogeography of the western United StatesmdashII Pacific Section Society of Economic Paleontologists and Mineralogists p 131-150

Rice DD and Claypool GE 1981 Generation accumulation and resource potential of biogenic gas American Association of Petroleum Geologists Bulletin v 65 no 1 p 5-25

Rudkin GH 1968 Natural gas in San Joaquin Valley California in Beebe BW and Curtis BF eds Natural gases of North America Tulsa Okla American Association of Petroleum Geologists Memoir 9 p 113-134

Sullivan JC 1963 Guijarral Hills oil field in Summary of operations California oil fields San Francisco Calif Annual Report of the State Oil and Gas Supervisor v 48 no 2 p 37-51 [also available in California Division of Oil and Gas Summary of Operations 1915-1999 California Division of Conservation Division of Oil Gas and Geothermal Resources Publication No CD-3 and at ftpftpconsrvcagovpuboilSummary_of_Operations1962]

Wilkinson ER 1960 Vallecitos field in Summary of operations California oil fields San Francisco Calif Annual Report of the State Oil and Gas Supervisor v 45 no 2 p 17-33 [also available in California Division of Oil and Gas Summary of Operations 1915-1999 California Division of Conservation Division of Oil Gas and Geothermal Resources Publication No CD-3 and at ftpftpconsrvcagovpuboilSummary_of_Operations1959]

5Neogene Gas Total Petroleum SystemmdashNeogene Nonassociated Gas Assessment Unit of the San Joaquin Basin Province

Figures

6 Petroleum Systems and Geologic Assessment of Oil and Gas in the San Joaquin Basin Province California

Figure 221 Location map of the San Joaquin Valley illustrating San Joaquin Basin Province boundary (bold black line) county boundaries (thin gray lines) Neogene Nonassociated Gas Assessment Unit boundary (blue line) play boundary from previous USGS assessment (purple line) and oil (green) and gas (red) fields in the province

2003 Assessment Unit1995 Play Boundary

121˚W 120˚W 119˚W

35˚N 35˚N

36˚N 36˚N

37˚N 37˚N

38˚N 38˚N

0 25

miles

7Neogene Gas Total Petroleum SystemmdashNeogene Nonassociated Gas Assessment Unit of the San Joaquin Basin Province

Figure 222 Detailed map of Neogene Nonassociated Gas Assessment Unit (AU) The blue line indicates the geographic limit of the AU The 18 gas fields and pools in this AU are colored red Fields outside the AU or within the map boundaries of the AU but assigned to a different assessment unit are outlined in black Black dots represent 1694 exploratory wells drilled for petroleum within the AU between 1916 and 2001 Well locations are from the California Department of Conservation Division of Oil Gas and Geothermal Resources and are available at ftpftpconservcagovpuboilmapsdist4 and at ftpftpconservcagovpuboilmapsdist5 Cross-section A-Arsquo is shown in figure 225 Township and range grid is indicated for scale and location scattered labels are relative to the Mount Diablo baseline and meridian City of Bakersfield (B) denoted with yellow square Gas field labels are ( fields used in the assessment secondary fields smaller than 3 BCF) Bo=Bowerbank Bu=Buttonwillow C=Canal CLN=Coles Levee North CLS=Coles Levee South DR=Dudley Ridge GC=Garrison City H=Harvester LL=Los Lobos P=Paloma RB=Rio Bravo S=Semitropic SNW=Semitropic Northwest SSE=Shafter Southeast St=Strand T=Trico TNW=Trico Northwest TS=Ten Section

11S19E

15S23E

20S14E

22S15E

25S17E

25S28E

28S19E

31S21E

11N24W

10N20W

CLNCLS

LL

P

RB

S

TS

Bo

Bu

H

S

T

TNW

GC SSE

CSt

St

SNW

B

0 10miles

120˚30W 120˚00W 119˚30W 119˚00W 118˚30W

35˚00N 35˚00N

35˚30N 35˚30N

36˚00N 36˚00N

36˚30N 36˚30N

37˚00N 37˚00N

DR

A

Arsquo

6 Petroleum Systems and Geologic Assessment of Oil and Gas in the San Joaquin Basin Province California

Figure 221 Location map of the San Joaquin Valley illustrating San Joaquin Basin Province boundary (bold black line) county boundaries (thin gray lines) Neogene Nonassociated Gas Assessment Unit boundary (blue line) play boundary from previous USGS assessment (purple line) and oil (green) and gas (red) fields in the province

2003 Assessment Unit1995 Play Boundary

121˚W 120˚W 119˚W

35˚N 35˚N

36˚N 36˚N

37˚N 37˚N

38˚N 38˚N

0 25

miles

7Neogene Gas Total Petroleum SystemmdashNeogene Nonassociated Gas Assessment Unit of the San Joaquin Basin Province

Figure 222 Detailed map of Neogene Nonassociated Gas Assessment Unit (AU) The blue line indicates the geographic limit of the AU The 18 gas fields and pools in this AU are colored red Fields outside the AU or within the map boundaries of the AU but assigned to a different assessment unit are outlined in black Black dots represent 1694 exploratory wells drilled for petroleum within the AU between 1916 and 2001 Well locations are from the California Department of Conservation Division of Oil Gas and Geothermal Resources and are available at ftpftpconservcagovpuboilmapsdist4 and at ftpftpconservcagovpuboilmapsdist5 Cross-section A-Arsquo is shown in figure 225 Township and range grid is indicated for scale and location scattered labels are relative to the Mount Diablo baseline and meridian City of Bakersfield (B) denoted with yellow square Gas field labels are ( fields used in the assessment secondary fields smaller than 3 BCF) Bo=Bowerbank Bu=Buttonwillow C=Canal CLN=Coles Levee North CLS=Coles Levee South DR=Dudley Ridge GC=Garrison City H=Harvester LL=Los Lobos P=Paloma RB=Rio Bravo S=Semitropic SNW=Semitropic Northwest SSE=Shafter Southeast St=Strand T=Trico TNW=Trico Northwest TS=Ten Section

11S19E

15S23E

20S14E

22S15E

25S17E

25S28E

28S19E

31S21E

11N24W

10N20W

CLNCLS

LL

P

RB

S

TS

Bo

Bu

H

S

T

TNW

GC SSE

CSt

St

SNW

B

0 10miles

120˚30W 120˚00W 119˚30W 119˚00W 118˚30W

35˚00N 35˚00N

35˚30N 35˚30N

36˚00N 36˚00N

36˚30N 36˚30N

37˚00N 37˚00N

DR

A

Arsquo

7Neogene Gas Total Petroleum SystemmdashNeogene Nonassociated Gas Assessment Unit of the San Joaquin Basin Province

Figure 222 Detailed map of Neogene Nonassociated Gas Assessment Unit (AU) The blue line indicates the geographic limit of the AU The 18 gas fields and pools in this AU are colored red Fields outside the AU or within the map boundaries of the AU but assigned to a different assessment unit are outlined in black Black dots represent 1694 exploratory wells drilled for petroleum within the AU between 1916 and 2001 Well locations are from the California Department of Conservation Division of Oil Gas and Geothermal Resources and are available at ftpftpconservcagovpuboilmapsdist4 and at ftpftpconservcagovpuboilmapsdist5 Cross-section A-Arsquo is shown in figure 225 Township and range grid is indicated for scale and location scattered labels are relative to the Mount Diablo baseline and meridian City of Bakersfield (B) denoted with yellow square Gas field labels are ( fields used in the assessment secondary fields smaller than 3 BCF) Bo=Bowerbank Bu=Buttonwillow C=Canal CLN=Coles Levee North CLS=Coles Levee South DR=Dudley Ridge GC=Garrison City H=Harvester LL=Los Lobos P=Paloma RB=Rio Bravo S=Semitropic SNW=Semitropic Northwest SSE=Shafter Southeast St=Strand T=Trico TNW=Trico Northwest TS=Ten Section

11S19E

15S23E

20S14E

22S15E

25S17E

25S28E

28S19E

31S21E

11N24W

10N20W

CLNCLS

LL

P

RB

S

TS

Bo

Bu

H

S

T

TNW

GC SSE

CSt

St

SNW

B

0 10miles

120˚30W 120˚00W 119˚30W 119˚00W 118˚30W

35˚00N 35˚00N

35˚30N 35˚30N

36˚00N 36˚00N

36˚30N 36˚30N

37˚00N 37˚00N

DR

A

Arsquo

8 Petroleum Systems and Geologic Assessment of Oil and Gas in the San Joaquin Basin Province California

Figure 223 Three-dimensional stratigraphy model of the Neogene Nonassociated Gas AU extracted from the EarthVisionreg model of the basin by Hosford Scheirer (this volume chapter 7) The major stratigraphic units within the AU are shown by colors see figure 224 for stratigraphic relations among the units Gas fields and pools (red) in the AU are draped on the topographic surface The San Joaquin Basin Province boundary (bold line) AU boundary (dashed line) and city names and locations float above the surface of the model View is from due south at a 30deg inclina-tion angle Vertical exaggeration is x4 EarthVision is a registered trademark (Marca Registrada) of Dynamic Graphics Inc Alameda Calif

9Neogene Gas Total Petroleum SystemmdashNeogene Nonassociated Gas Assessment Unit of the San Joaquin Basin Province

Gatchell sd

Brown Mtn ss

Oceanic sand

Zilch fm

Leda sd Tumey formationTumey formation

Antelope shStevens sd

Fruitvaleshale

Nozu sd

Rio Bravo sd

Fam

oso

sand

Fam

oso

sand

Alluvium Alluvium

Basement rocks Basement rocks

Ragged Valley silt

Wheatville sd

San Carlos sd

Santos

Wygal Ss Mbr

Cymric ShaleMbr

Agua SsBed

Panoche Fm

Vedd

er S

and

CarnerosSs Mbr

Vaqu

eros F

m

Arroyo Hondo Sh Mbr

Lodo Fm

Moreno Fm

Joaquin Ridge Ss Mbr

Cantua Ss Mbr

Kreyenhagen Formation Kreyenhagen Formation

PLEIS

PLIOZE

MO

RR

IAN

CH

ENEY

IAN

YNE-

ZIA

NPE

NU

TIA

NU

LATS

IAN

NA

RIZ

IAN

BU

LI-

TIA

N

REF

MIO

CEN

EN

EOG

ENE

Con

verg

ent m

argi

n an

dSi

erra

n m

agm

atis

m

OLI

GO

CEN

EEO

CEN

EPA

LEO

GEN

EPA

LEO

CEN

EM

AA

STR

ICH

CR

ETA

CEO

US CA

MPA

NIA

N

SANT

ALB

IAN

CEN

O

TUR

CON

Tran

s-pr

essi

onD

iabl

o R

ange

uplif

t and

bas

in

subs

iden

ce

Domengine Fm

Pointof Rocks SsMbr

Tulare Fm

KRSanta Margarita

Ss

San Joaquin Fm San Joaquin Fm

McDonald Sh Mbr

Round Mtn Silt

FreemanSilt

Jewett Sand

OlceseSand

Media Sh Mbr

Devilwater ShMbrGould Sh

Mbr undiff

B=Buttonbed Ss Mbr

Etchegoin Fm Etchegoin FmReef Ridge Sh Mbr Chanac

Fm

Reef Ridge Sh Mbr

McLure Shale Mbr

SYSTEM SERIES STAGE

West WestEast EastCENTRAL SOUTH

DEL

LUI

REL

SAUC

ESIA

NM

OHNI

AN

MaMega-

sequences(2nd order)

Monterey Fm

Temblor Fm

Temblor Fm

LATE

EAR

LY

Flat

sla

b su

bduc

tion

and

Lara

mid

eor

ogen

y

basin axis basin axis

unna

med

unna

med

unna

med

unna

med

unna

med

unna

med

unna

med

unna

med

unnamed

unnamedCanoas Slts Mbr

PH=Pyramid Hill Sd MbrKR=Kern River Fm

Wal

ker F

m

Monterey Fm

YokutSs

Sh Mbr

B

PH

120 Ma 120 Ma160 Ma160 Ma

Trip

le ju

nctio

n

mig

ratio

nSu

bduc

tion

and

m

agm

atis

m

undifferentiatedCretaceous

SantaMargaritaSs

unnamed

undifferentiated Cretaceousmarine and nonmarine strata

0

5

10

15

20

25

35

40

30

45

50

65

80

75

70

60

55

85

90

95

100

105

110

~~~~

Gas reservoir rock

Potential marine reservoir rock

Potential nonmarine reservoir rock

Oil-prone sourcerock

Gas-prone sourcerock

Nonmarine coarse grained

rockMarine coarse grained rockCoast Range ophioliteGranitic basement

Clayshalemudstone

biosiliceousHiatus or loss by erosion

Oil reservoir rock

PacificOcean

North

Central

South

WWF

SIERRA NEVADA

SAN ANDREAS FAULT

San Joaquin Basin Province

basin axis

Bakersf

ield Arch

0 25

miles

121˚W 120˚W 119˚W

36˚N

35˚N

37˚N

38˚N

DDPH

DRT

J

DCNDC

SAN EMIGDIO

TECHAPI

MOUNTAINS

COAST RANGES

Stockton Arch

Figure 224 Generalized stratigraphic column for the southern and central San Joaquin Basin Prov-ince showing hydrocarbon reservoir rocks and potential hydrocarbon source rocks See Hosford Scheirer and Magoon (this volume chapter 5) for complete explanation of the figure Formation names in italics are informal and are defined as follows Antelope shale of Graham and Williams (1985) Stevens sand of Eckis (1940) Fruitvale shale of Miller and Bloom (1939) Nozu sand of Kasline (1942) Zilch formation of Loken (1959) Rio Bravo sand of Noble (1940) Oceanic sand of McMasters (1948) Tumey formation of Atwill (1935) Leda sand of Sullivan (1963) Famoso sand of Edwards (1943) Gatchell sand of Goudkoff (1943) San Carlos sand of Wilkinson (1960) Wheatville sand of Cal-laway (1964) Brown Mountain sandstone of Bishop (1970) and Ragged Valley silt of Hoff-man (1964)

10 Petroleum Systems and Geologic Assessment of Oil and Gas in the San Joaquin Basin Province California

SemitropicField

ButtonwillowFieldTrico

Field

Tulare Fm

San Joaquin FmEtchegoin Fm

Ante

lope

shale

Antelope shaleTemblor Fm

A ArsquoNorth South

basement rock

pre-Temblor Fm

06 Ro09 Ro

Questionablesource rock

Gas field

Explanation

PetroleumWindow

(oil + gas)

0

5

10

15

20

25 0 5 10 15 20 kmScale

N

Dep

th (x

1000

ft)

of Graham and Williams (1985)

Neogene Nonassociated Gas AU

Figure 225 Cross section A-Arsquo through biogenic gas fields of the southern San Joaquin Basin Location of cross-section is shown on figure 222 Stratigraphically the AU extends from the ground surface down to the base of the Etchegoin Formation Fm Formation Ro percent vitrinite reflectance Modified from Magoon and others (this volume chapter 8)

11Neogene Gas Total Petroleum SystemmdashNeogene Nonassociated Gas Assessment Unit of the San Joaquin Basin Province

FORMATIONMEMBERamp ZONE

TYPICALELECTRIC

LOGSERI

ESPL

EIST

OCEN

EPL

IOCE

NE

MIO

CEN

E

ReefRidgeShale

Member

Mon

tere

y Fo

rmat

ion

2nd Mya sand

C zone

EtchegoinFormation

Antelopeshale ofGraham

andWilliams

(1985)

San

Joaq

uin

Form

atio

n

20 foot sand

200 foot shale

1st Mya sd

upperArlington sd

lowerArlington sd

Kern 5

B zo

ne

Buttonwillow Gas Field

T27 S R 22 E

T28 S R 22 E

T28 S R 23 E

T27 S R 23 E

Contours on top of B zone

31

1 56

987

1617

-2600

-2400

-2300

-2500

alluvium

Tulare Formation

SanJoaquin

Formation

Etchegoin Formation

200 foot shale

C zone

B zone

A B

B

A

36

of Kaplow (1940)

contoured horizon

1 mile

1 mile

Figure 226 Map cross-section and stratigraphic column of Buttonwillow gas field illustrating typical stratigraphic sand lenses in the Neogene Nonassociated Gas AU Green shading (underlying township-range grid) denotes reported 1998 limits of productive sand units within the fields All depths are in feet Formations in italics denote informal geologic names Informal names not previously defined are the 20 foot sand Arlington sand Kern 5 first Mya sand second Mya sand B zone C zone and 200 foot shale all of Kaplow (1940) See figure 222 for location of field Figure redrafted from CDOGGR (1998) sd sand

12 Petroleum Systems and Geologic Assessment of Oil and Gas in the San Joaquin Basin Province California

-2300

-2250

-2250

-2250

-2250

-2250

-2200

-2200

-2200-2200

-2200

-2200

-2250

-2300

Trico Gas Field

35 36 31 32 33 34

3456

7 8 9 10 11 12

15

12

11

1314 18 17 14 13

24

2526282925

2423

26 30

35

1

12 7 8 9 10 11 12 7

6 5 4 2 1 6 5

36 31 32 33 34 3635

232019

T 25S R 24ET 25S R 22E

T 24S R 23E

T 23S R 23ET 23S R 22E

T 24S R 22E

Kern

T 25S R 23E

County

King

s

Cou

nty

Tula

re

Cou

nty

-2350

-2300

-2400-2350

-2350

BA

Contours onfirst Mya sand

Electric log marker

first Mya sand E-log marker Tulare Fm contoured horizon

Atwell Island sand

BA

San Joaquin Fm

C zone

SER

IES

PLEI

ST

PLIO

CEN

EM

IOC

ENE Mon

tere

y Fm

OLI

GO

CEN

EEO

CEN

ELA

TE C

RETA

CEO

US (

)

Tulare Fm

first Mya sd

San Joaquin Fm

Atwell Islandsd

Etchegoin Fm

Round MountainSilt

Olcese Sand

Freeman Silt-Jewett Sand

Pyramid Hill SdMbr of Jewett Sd

Vedder Sand

Tumey fm of Atwill(1935)

KreyenhagenFm

Walker Fm

-2270

-2300

-2350

undiffer-entiatedmarinestrata

of Kaplow (1940)

1 mile

1 mile

FORMATIONMEMBERamp ZONE

TYPICALELECTRIC

LOG

Figure 227 Map cross-section and stratigraphic column of Trico gas field illustrating typical asymmetrical anticlinal trap in the Neogene Nonassociated Gas AU Green shading (underlying township-range grid) denotes reported 1998 limits of productive sand units within the fields All depths are in feet Formations in italics denote informal geologic names Informal names not previously defined are Tumey formation of Atwill (1935) and Atwill Island sand of Kaplow (1940) See figure 222 for location of field Figure redrafted from CDOGGR (1998) Fm Formation fm formation Mbr Member Pleist Pleistocene Sd Sand sd sand

13Neogene Gas Total Petroleum SystemmdashNeogene Nonassociated Gas Assessment Unit of the San Joaquin Basin Province

Neogene Nonassociated Gas Assessment Unit 50100501

1

10

100

1000

1920 1930 1940 1950 1960 1970 1980 1990 2000

ACCUMULATION-DISCOVERY YEAR

KN

OW

N G

AS

-AC

CU

MU

LA

TIO

N S

IZE

(B

CF

G)

Figure 228 Gas-accumulation size versus year of accumulation discovery in the Neogene Nonassociated Gas AU Figure is excerpted from data file k100501pdf (see Klett and Le this volume chapter 28 for explanation of data file)

12 Petroleum Systems and Geologic Assessment of Oil and Gas in the San Joaquin Basin Province California

-2300

-2250

-2250

-2250

-2250

-2250

-2200

-2200

-2200-2200

-2200

-2200

-2250

-2300

Trico Gas Field

35 36 31 32 33 34

3456

7 8 9 10 11 12

15

12

11

1314 18 17 14 13

24

2526282925

2423

26 30

35

1

12 7 8 9 10 11 12 7

6 5 4 2 1 6 5

36 31 32 33 34 3635

232019

T 25S R 24ET 25S R 22E

T 24S R 23E

T 23S R 23ET 23S R 22E

T 24S R 22E

Kern

T 25S R 23E

County

King

s

Cou

nty

Tula

re

Cou

nty

-2350

-2300

-2400-2350

-2350

BA

Contours onfirst Mya sand

Electric log marker

first Mya sand E-log marker Tulare Fm contoured horizon

Atwell Island sand

BA

San Joaquin Fm

C zone

SER

IES

PLEI

ST

PLIO

CEN

EM

IOC

ENE Mon

tere

y Fm

OLI

GO

CEN

EEO

CEN

ELA

TE C

RETA

CEO

US (

)

Tulare Fm

first Mya sd

San Joaquin Fm

Atwell Islandsd

Etchegoin Fm

Round MountainSilt

Olcese Sand

Freeman Silt-Jewett Sand

Pyramid Hill SdMbr of Jewett Sd

Vedder Sand

Tumey fm of Atwill(1935)

KreyenhagenFm

Walker Fm

-2270

-2300

-2350

undiffer-entiatedmarinestrata

of Kaplow (1940)

1 mile

1 mile

FORMATIONMEMBERamp ZONE

TYPICALELECTRIC

LOG

Figure 227 Map cross-section and stratigraphic column of Trico gas field illustrating typical asymmetrical anticlinal trap in the Neogene Nonassociated Gas AU Green shading (underlying township-range grid) denotes reported 1998 limits of productive sand units within the fields All depths are in feet Formations in italics denote informal geologic names Informal names not previously defined are Tumey formation of Atwill (1935) and Atwill Island sand of Kaplow (1940) See figure 222 for location of field Figure redrafted from CDOGGR (1998) Fm Formation fm formation Mbr Member Pleist Pleistocene Sd Sand sd sand

13Neogene Gas Total Petroleum SystemmdashNeogene Nonassociated Gas Assessment Unit of the San Joaquin Basin Province

Neogene Nonassociated Gas Assessment Unit 50100501

1

10

100

1000

1920 1930 1940 1950 1960 1970 1980 1990 2000

ACCUMULATION-DISCOVERY YEAR

KN

OW

N G

AS

-AC

CU

MU

LA

TIO

N S

IZE

(B

CF

G)

Figure 228 Gas-accumulation size versus year of accumulation discovery in the Neogene Nonassociated Gas AU Figure is excerpted from data file k100501pdf (see Klett and Le this volume chapter 28 for explanation of data file)

13Neogene Gas Total Petroleum SystemmdashNeogene Nonassociated Gas Assessment Unit of the San Joaquin Basin Province

Neogene Nonassociated Gas Assessment Unit 50100501

1

10

100

1000

1920 1930 1940 1950 1960 1970 1980 1990 2000

ACCUMULATION-DISCOVERY YEAR

KN

OW

N G

AS

-AC

CU

MU

LA

TIO

N S

IZE

(B

CF

G)

Figure 228 Gas-accumulation size versus year of accumulation discovery in the Neogene Nonassociated Gas AU Figure is excerpted from data file k100501pdf (see Klett and Le this volume chapter 28 for explanation of data file)

14 Petroleum Systems and Geologic Assessment of Oil and Gas in the San Joaquin Basin Province California

Field

Estimated Ultimate

Recoverable Gas through 2002 (BCF)

Percent of Total Number of

Producing Wells in 2002

Trico 2014 486

5

Coles Levee South 439 106 2

Buttonwillow 384 93 0

Paloma 260 63 2

Bowerbank 249 60 7

Semitropic 239 58 3

Coles Levee North 130 31 2

Rio Bravo 111 27 0

Ten Section 91 22 0

Trico Northwest 91 22 0

Harvester 89 22 0

Dudley Ridge 49 12 0

Total 4146 1000 21

Table 221 Production statistics for primary fields in the Neogene Nonassociated Gas Assessment Unit

[Recoverable gas is the sum of cumulative production and estimated proved reserves Data source is CDOGGR (2003) BCF billion cubic feet Primary fields are defined as those with recoverable gas equal to or greater than 3 BCF Six additional fields have recoverable gas of less than 3 BCF Five fields () were analyzed for assessment purposes Fields with zero producing wells are abandoned]

• Title page
• Contents
• Summary
• Description
• Source Rocks
• Maturation and Migration
• Reservoir Rocks
• Traps and Seals
• Exploration Status and Resource Potential
• References Cited
• Figures
• • Figure 221
  • Figure 222
  • Figure 223
  • Figure 224
  • Figure 225
  • Figure 226
  • Figure 227
  • Figure 228
  • • Table
    • • Table 221
      • • Appendixes (link)