96829-ms-p-a strategic gasfield development case in sandston

7/23/2019 96829-Ms-p-A Strategic Gasfield Development Case in Sandston

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Copyright 2005, Society of Petroleum Engineers

This paper was prepared for presentation at the 2005 SPE Annual Technical Conference andExhibition held in Dallas, Texas, U.S.A., 9 12 October 2005.

This paper was selected for presentation by an SPE Program Committee following review ofinformation contained in a proposal submitted by the author(s). Contents of the paper, aspresented, have not been reviewed by the Society of Petroleum Engineers and are subject tocorrection by the author(s). The material, as presented, does not necessarily reflect anyposition of the Society of Petroleum Engineers, its officers, or members. Papers presented atSPE meetings are subject to publication review by Editorial Committees of the Society ofPetroleum Engineers. Electronic reproduction, distribution, or storage of any part of this paper

for commercial purposes without the written consent of the Society of Petroleum Engineers isprohibited. Permission to reproduce in print is restricted to a proposal of not more than 300words; illustrations may not be copied. The proposal must contain conspicuousacknowledgment of where and by whom the paper was presented. Write Librarian, SPE, P.O.Box 833836, Richardson, TX 75083-3836, U.S.A., fax 01-972-952-9435.

Abst ractThe objective of this paper is to present a process for

improving the planning of gas field development. We discusshow seismic amplitudes and dynamic characterization can be

combined to optimize gas field development. The main

concepts, methodologies, and tool used, as well as resultsobtained are shown for an actual Mexican gas field. A series

of amplitude seismic maps were constructed by using 3D

seiesmic interpretation. These maps were the essential part for

detecting significant volumes of gas in place. Afterwards,calibrations of these maps with production data used in reserveevaluation studies resulted in a low risk development strategy

for the field. The gas field example is comprised of three

producing sandstones at different depths (E, G, and M), andhas 14 producing wells. Hydraulic communication and the

drainage areas for each reservoir, in both E and M sandstones,

were evaluated through a combination of the amplitude in the

seismic anomalies and production data analysis. A goodagreement between the seismic amplitude and dynamic

characterization of the pressure and production data was

obtained, which improved the evaluation of the reservoir

quality and the estimation of drainage area, original gas in

place, and proved reserves. In E and M sandstones, four andthree independent reservoirs have been detected, respectively.

The E sandstone has an estimated value of 62 Bscf of original

gas in place and the M sandstone has an estimated value of110 Bscf of original gas in place. By using the reservoir

dynamic model in combination with information of logs,

cores, and production data, the economic optimum strategy forthe field development was designed, that included the drilling

of wells in areas with the best seismic amplitude.

IntroductionThe gas field discussed in the present paper is located in thecentral area of the Veracruz basin, at the southeast of the Port

of Veracruz in Mexico. The field was discovered in 1921 withthe exploratory well 1, which was perforated by a foreign

company.

The field is formed by many lenticular Tertiary sandstones

with gas and abnormal pressures.The first producer well (well-3) was completed in 1962

Twenty five wells have been perforated in this field. Fourteen

wells resulted gas producers (3, 4, 5, 6, 201, 402, 403, 404405, 406, 412, 415, 420, and 436 wells), nine wells resulted

being invaded with water (10, 12, 13, 15, 101, 407, 414, 428

and Ma-1 wells) and one well resulted plugged up by a

mechanic accident (well-102).In 1999 several 3D seismic surveys were performed

covering an area of 240 km2 (or 59,305-acre). The

interpretation of 3D seismic allowed the construction of

diverse amplitude seismic maps. These maps were essentia

for detecting significant volumes of gas with relation to highamplitude seismic areas, while establishing geological models

and delimiting stratigraphic features.

The amplitude seismic maps were calibrated with reservoir

and fluid properties, as well as production data obtainedthrough productive wells from different sandstones, allowed

the decrease of economical risk in the development of the gas

field and the generation of new exploration opportunities.Table 1 shows the well name, the reservoir and fluid data

for each producer sandstone.

Currently, the gas field is comprised of three main

producing sandstones: the sandstones at the base of the LowPliocene (layer E located at 1600-1680 meters or 5249-5512

feet of depth), whose exploitation started on November of

1969 with well-5; the sandstones of the Upper Miocene (layerG, located at 2050-2250 meters or 6726-7382 feet of depth)

whose exploitation started on August of 1966 with wells 3, 4

and 6; and the sandstones of the Late Medium Miocen (layer

M located at 2500-2700 meters or 8202-8858 feet of depth)

whose exploitation started on August of 1988 with well-201.The fundamental objective of this work is to present the

results of a synergy oriented reservoir management study

performed under a team work effort, in reevaluating the

strategic plan to develop a gas field with the main purpose ofachieving an economical optimization.

Several gas reservoirs were identified by using hydrauliccommunication that exists among the E, G and M

sandstone layers, through the combination of geologica

features, amplitude seismic maps and dynamic

characterization (production analysis of pressure and

SPE 96829

A Strategic Gasfield Development Case in Sandstones Using Seismic Amplitudesand Dynamic Reservoir CharacterizationJ.A. Arvalo-Villagrn and H. Cinco-Ley, Pemex E&P; F. Samaniego-Verduzco, UNAM; and N. Martnez-Romero,Pemex E&P


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2 SPE 96829

production data)1-4, which improved the evaluation of the

reservoir quality and the estimation of drainage areas, original

gas in place, and proved reserves of gas, as well as the numberof additional wells required to drain each identified reservoir.

Field production dataProduction of the gas field started on August of 1966 through

four wells (3, 4, 5 and 6), with an overall initial rate of 8MMscf/D.

Figure 1 shows the production history (gas rate, qg, andcumulative gas production, Gp) for each reservoir layer and

the whole field production.

In August 1thof 2002, the field was producing with a total

gas rate of 64.4 MMscf/D, corresponding 2.0 MMscf/D (3%),

11.4 MMscf/D (18%), and 51.0 MMscf/D (79 %) to the E,G, and M layers, respectively.

Layer E has produced 21.2 Bscf of gas through seven

producing wells (3, 5, 6, 403, 405, 406, and 412) for over 15

years of effective producing time. Layer G has produced36.7 Bscf through seven wells (3, 4, 6, 402, 404, 406, and

436), for over 20 years of continuous production. Finally,layer M has reached a cumulative gas production of 20.6

Bscf through six producing wells (201, 402, 405, 412, 415,

and 420), within 4 years of continuous production.

In layer E there are four wells still on the drilling process

(C-1, 419, 439, and 804) and other five wells were closed due

to requirements of compression facilities (3, 5, 6, 404, and406).

Layer E presents a cumulative gas production, Gp, per

well between 0.5 and 0.7 Bscf/year. Similarly, layer Gpresents a Gpper well between 0.5 and 1.0 Bscf/year, while

the most prolific layer M presents a Gpper well between 2

and 3 Bscf/year. However, in all three sandstone layers thereare some wells with higher production levels than the

previously mentioned, so this might imply that some of thewells drain volumes of gas coming from different geological

channels, in addition the existence of a common area among

many wells.On the other hand, the good correlation among the fluid

analysis, initial pressures, and the historical pressures

registered from the producer intervals of each well, indicatesthat there is communication among some wells belonging to

the same sandstone reservoir. On a complementary way,

similar responses on the geophysical well logs plus the low

pressure registered on the last drilled wells which crossedthrough the E sandstone (403, 405, 406, and 412), allowed

the inference that their volumes of gas were drained

beforehand because of the possible communication amongwells.

Based on the physical characteristics previously described,the problem be solved consisted of identifying the dynamic

communication that exists in each one of the sandstone layers

within the field, as well as, the evaluation of drainage areas,original gas in place, and the optimum number of wells.

Discussion and results

Dynamic characterization process. In order to reach the

main objective of this study, the integration of explorationists

and petroleum engineers was required, which produced a

feedback to the geological model when they worked between

the static model and the dynamic model.

When applying the technique of dynamic characterizationfor each sandstone reservoir (E, G, and M), an

individual analysis was performed (well after well) and

simultaneous analysis between wells, estimating on this way

for some wells, their drainage areas and their original gas in

place. The process of dynamic characterization includedseveral techniques for filtering, validating, and analyzing well

data (fluids, cores, logs, pressure, and production data for eachwell, etc.)1-4. Diagnostic and specialized flow plots, as well as

techniques for analyzing well tests were required3.

Several studies and methodologies including noda

analysis, volumetric material balance, reservoir simulation

and preliminary economic analyses were used, in order todetermine the number of wells required to drain each

identified reservoir.

As mentioned a feedback process between static and

dynamic model using a dynamic characterization tecnique waapplied for each reservoir identified, where the amplitude

seismic maps were compared with well data (pressure andproduction), giving as a result an excellent correlation between

them.

Analysis of the initial pressures from E, G, and M

sandstones layers. Figure 2 presents a plot of the initia

pressures of the producing wells from the field. These initiapressures were calibrated as a function to their average depth

of the producer interval. The three current producing horizons

(E, G and M layers), are shown on the graph.On the same graph, two straight slating lines are also

included, where the left line corresponds to the gradien

formation (water of 1.05 g/cc) and the right line indicates thenormal pressure, adding 90 kg/cm2 (or 1,280 psia), which

corresponds to the geopressured initial pressure of the well-201 in the M layer.

On figure 2, as well, it is shown that for the three

producing sandstones the majority of the initial pressurefound in the wells, are located in the region enclosed by both

straight slating lines, indicating, therefore, abnormal pressure

much higher than the normal hydrostatic calculated onesAlso, the plot shows the tendency of the abnormal pressure

increasing with depth, which indicates that the deepest gas

sandstones are the most attractive from the point of view of

production and volume of gas.In wells 3, 5 and 6 on the E layer, located at

approximately 1,645 meters of depth (or 8,858 feet of depth)

pressures much higher than the normal pressure were foundHowever, in well-403, which was completed on July of 1999

on the E layer, a lower pressure than the normal was foundindicating that this area had already been drained by other

wells.

In well-405 a higher pressure than the one on well-403 wafound, but lower than the normal pressure (possibly, it

indicates as well, the drainage of the area by other wells). In

most recent wells (406 and 412), a much lower pressure thanthe one in well-403 was detected.

The previous information allows the inference of the

presence of a certain degree of communication between well-5

and well-412, and between well-403 and well-406, which


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SPE 96829 3

found the E layer depleted because of production of wells

like the wells 3, 5, and 6.

Dynamic characterization results for E sandstone layer.

For the productive area of the E layer, three independent gas

reservoirs were identified, which have communication among

them.

Figure 3 shows the amplitude seismic map for the threeidentified reservoirs. These reservoirs are: E-1 that includes

the volume drained by wells 3, 6, 403, and 406; E-2 thatincludes the volume drained by wells 5 and 412; and the E-3

that includes only the volume drained by well-405.

Table 2 shows the results obtained from the dynamic

characterization for each well. Similarly, Table 3 presents the

calculated results obtained through a simultaneous dynamiccharacterization among reservoirs. For E-1, E-2, and E-3

reservoirs drainage areas of 964, 213, 38 acres were estimated,

respectively, corresponding to original gas in place of 23.3,

10.0 and 1.2 Bscf, considering recovery factors of 58, 70, and43%, respectively.

As a result we observed that the actual wells completed inE-1, E-2, and E-3 reservoirs are enough to drain the remaining

volume of gas. However, it is suggested to prove the

continuity of the E-2 reservoir during the drilling process of

the well-427 (figure 3), whose objective will be a deeper layer

than layer E.

Based on the production tests performed in well-414(invaded with brine), it was confirmed that there is no

accumulation of gas in the E-1 reservoir to the East of the

field. Therefore, it is not recommended to drill wells in theprospects 411 and 414D for being located within an area of

salt water.

Taking into account the results obtained in well-428(invaded by water and low pressure gas), it was recommended

to suspend the drilling of the well-429 and do not drill well-431.

Dynamic characterization results for G sandstone

reservoir. Based on the pressure data registered at the

beginning of each producer well and to the different pressure

and production behavior of each well, through the process ofdynamic characterization, it was concluded that each

producing well drains an independent area.

On this sandstone, seven producing reservoirs were

identified (from G-1 to G-7), which made necessary toconsider the results in a conservative way (figure 4). Tables 2

and 3 along with figure 4 show the drainage areas of G

sandstone layer.In this case, the drainage areas were affected for the

presence of the aquifer (lateral and/or from the bottom),causing difficulties for the dynamic characterization process.

Therefore, low trustworthy information was obtained

regarding the communication degree among wells and thecalculation of the original gas in place.

In a similar way, for the characterization of this sandstone

additional studies such as material balance, declined curvesand numeric simulation were required, all based on the

geological model that represents the sandstone.

Finally, it is not recommended to drill additional wells on

this active hydraulic drive sandstone.

Dynamic characterization results for M sandstone

reservoir. Table 2 shows the results of the original gas in

place, GBgi, and of the current recovery factors for each welland Table 3 includes the results of the simultaneous dynamic

characterization for each reservoir in the M sandstone.

For this sandstone, three reservoirs were identified, which

are communicated within them.

Figure 5 shows the amplitude seismic map of the threeidentified reservoirs. These reservoirs are: M-1 which includes

the drainage volume of the well-201; M-2 which includes thevolume drain by well-402; and M-3 which includes the wells

405, 412, 415, and 420.

For the M-1, M-2 and M-3 reservoirs, there the estimated

drainage were areas of 247, 346, 494 acres, respectively, and

the calculated original gas in place were 23.6, 33.5, and 52.8Bscf, with recovery factors of 39, 20, and 5 %, respectively.

Material balance and reservoir simulation studies indicated

that two wells are suitable to exploit the M-2 sandstone

(currently, the well-419 is drilling), and no additional wells arerequired to exploit M-1 and M-3 sandstones.

It is convenient to mention, in order to avoid a high andearly production of water in the producer wells of the M-3, i

is suggested to exploit this reservoir at a gas rate less than 30

MMscf/D.

Finally, with the objective of updating and feedback the

reservoir geological model, an effective program o

scheduling and taking well information is recommended.

Conclusions and recommendationsThe objective of this paper has been to present a process forimproving the planning of gas field development, through the

use of both seismic amplitude maps and dynamic

characterization. Based on the work of a multidisciplinaryteam work, an integral reservoir management was applied to

the E, G and M sandstones of a Mexican gas field, aswell as the remaining gas reserves. We are able to present the

following conclusions and recommendations:

1. A good qualitative correlation was identified among theseismic amplitude maps, the production data, and the

dynamic characterization process.

2. Three reservoirs were identified in the E sandstone: E-1includes wells 3, 6, 403, and 406; E-2 by the wells 5 and

412; and E-3, which includes well-405 (figure 3).

3. The number of wells currently existing on E-1, E-2 and E-3 sandstones is enough to drain the gas reserves. Howeverit is recommended to prove the continuity of the E-2

reservoir while the well-427a is on drilling, of which

objective is a deeper sandstone than E (figure 3).4. Based on the results obtained by well-414 (invaded of

water), it is confirmed the non presence of gas within E-1reservoir to the East of the field. Therefore, it is no

recommended the drilling of wells 411 and 414D because

they are located within a water saturated area (figure 3).5. The seismic amplitude at the west of the E sandstone

needs to be proved through the drilling of the well Ce-1. In

case of proving the gas accumulation, it is required to takethe necessary information to determine the optimum

number of wells to be drilled (figure 3).

6. Taking into account the results obtained in the well-428(invaded by water and low pressure gas), it was


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4 SPE 96829

recommended to stop the drilling of the well-429 and

cancels the drilling of well-431 (figure 3).

7. The producing areas from the G sandstone, show a stronghydraulic drive (lateral and/or from the bottom), and the

production and pressure behavior of the wells is practically

different among them. On this sandstone, seven producing

reservoirs were identified (from G-1 to G-7, figure 4).

8. It is not recommended the drilling of additional wellshaving as main objectives the reservoir from the G

sandstone, since it presents an active hydraulic drive.9. On the M sandstone, three producer reservoirs were

identified: M-1, which includes the well-201; M-2, which

includes the well-402; and M-3, which includes the wells

405, 412, 415, and 420 (figure 5).

10.It is not recommended the drilling of additional wellshaving as objectives M-1 and M-3 reservoirs.

11.To optimize the exploitation of the M-2 reservoir, it hasdetermined through material balance and reservoir

simulation studies, that two producing wells (402 and 419wells, figure 5) are required to reach a recovery factor of

75% in a period of 10 years.12.In order to avoid a fast and early production of water in the

producing wells of the M-3 reservoir, it is suggested to

exploit this reservoir at a gas rate less than 30 MMscf per

day.

13.With the objective of updating and feedback the reservoirgeological model, the implementation of an effective datacollection program is recommended.

AcknowledgementWe would thank to Pemex Exploration and Production for

permission to present the results of this study. We are also

thankful to the geoscientists and engineers at the VeracruzAsset and the Strategic Program of Gas, whose effective team

work and participation contributed to do the work presented inthis paper.

NomenclatureA = drainage area, acres, km2Bgi = gas formation volume factor, cf r.c./scfFgr = recovery gas factor, percenthnet = net thickness, ft, metersG = original gas in place, BscfGBgi = original gas in place, cf r.c.Gp = cumulative gas production, Bscfk = effective permeability, md

pi = initial pressure, psia, kg/cm2abs

qg = gas rate, MMscf/DS

wi = initial water saturation, fraction

Ty = reservoir temperature,oR

= formation porosity, fractiong = gas gravity

References1. Cinco-Ley, H.: Caracterizacin Dinmica de Yacimientos,

Colegio de Ingenieros Petroleros de Mxico, April-June 1999Mxico, D.F.

2. Avendao-Rodriguez, J.L. and Cinco-Ley, H.: CaracterizacinDinmica en Campos de Gas Seco. Caso Novillero 14 y SanPablo 4.,Ingeniera Petrolera, June 2000, Mxico, D.F.

3. Arvalo-Villagrn, J.A.: Analysis of Long-Term Behavior in

Tight Gas Reservoirs, PhD dissertation, Texas A&M UniversityCollege Station, Texas, USA, August 2001.4. Avendao-Rodriguez, J.L, Cinco-Ley, H., Arvalo-Villagrn

J.A:, and Rebolledo-Domnguez, J.A.: CaracterizacinDinmica del Campo Novillero, Ingeniera Petrolera, July2002, Mxico, D.F.

*Conversin factor is exact.

SI Metric Conversion Factors

acre x 4.046 873 E+03 =m2

bbl x 1.589 873 E-01 =m3

cp x 1.0* E-03 =Pa/s

ft x 3.048* E-01 =m

md ft x 3.008 142 E+02 =m2

psi x 3.048* E+00 =KPa

psi-1

x 1.450 377 E-04 =Pa-1

cu ft x 2.831 685 E-02 =m3

md x 9.869 233 E-04 =m

R x 5/9 = K


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SPE 96829 5

5

Table 1 - Reservoir and fluid data for each producer sandstone in the gas field.

Producer

sandstone

Well

name

Producer

intervals

(feet subsea)

Production

time

(%)

Sw(%)

hnet(ft)

k

(md)

p i(psia)

Ty(F)

g

E 3 5353-5369 Jul 92-Ago 00 22 31 39 30 2,538 150 0.558

5304-5317 D ic 99-Ago 00

E 5 5350-5383 Oct 69-Oct 00 22 31 39 30 2,631 150 0.557

E 6 5359-5373 Jul 92-Feb 01 24 30 10 30 2,538 150 0.558

E 403 5294-5320 Jul 99-Actual 27 25 52 12 2,538 150 0.558

5340-5373 Jul 99-Actual

E 405 5770-5789 Abr 01-Sep 01 28 25 23 102 2,279 150 0.557

E 406 5629-5625 Mar 02-Abr 02 25 40 7 28 2,538 150 0.558

E 412 5327-5360 May 0 2-Actual 26 31 26 20 2,631 150 0.557

G 3 6980-6996 Ago 66-Ene 75 20 39 62 10 3,987 190 0.600

6920-6934 Jul 92-May 02

6947-6960 Jul 92-May 02 21 36 43 4 2,866 164 0.570

G 4 7068-7082 Ago 66-Sep 74 22 64 43 10 4,455 180 0.620

7022-7039 Jul 92-May 97 22 64 43 10 4,455 180 0.620

G 6 7242-7255 Ago 66-Ene 75 24 12 30 10 4,000 190 0.600

G 402 7065-7085 Jul 99-Jul 00 28 33 49 30 3,800 190 0.570

G 404 7412-7436 Dic 00-May 01 25 25 33 201 3,751 170 0.580

G 406 7423-7436 Mar 02-Actual 18 29 49 162 3,710 169 0.570

G 436 7423-7436 Mar 02-Actual 20 22 45 15 3,715 169 0.570

M 201 8413-8433 Ago 98-Actual 28 28 52 6 5,200 179 0.568

M 402 8843-8856 Sep 00-Actual 28 28 52 6 4,954 180 0.565

M 405 9637-9650 Oct 01-Actual 20 20 49 54 5,313 180 0.569

M 412 9643-9476 May 02-Actual 60 5,350 180 0.576

9545-9561 May 02-Actual 62 5,240 179 0.574

M 415 10102-10116 Jul 02-Actual 70 5,610 190 0.568

M 420 80 5,550 185 0.564


Producer

sandstone

WellProducer

intervals

(feet subsea)

Production

time

(%)

Sw

(%)

hnet

(ft)

k

(md)

p i

(psia)

Ty

(F)g

E 3 5353-5369 Jul 92-Ago 00 22 31 39 30 2,538 150 0.558

5304-5317 Dec 99-Ago 00

E 5 5350-5383 Oct 69-Oct 00 22 31 39 30 2,631 150 0.557

E 6 5359-5373 Jul 92-Feb 01 24 30 10 30 2,538 150 0.558

E 403 5294-5320 Jul 99-Actual 27 25 52 12 2,538 150 0.558

5340-5373 Jul 99-Actual

E 405 5770-5789 Apr 01-Sep 01 28 25 23 102 2,279 150 0.557

E 406 5625-5629 Mar 02-Abr 02 25 40 7 28 2,538 150 0.558

E 412 5327-5360 May 02-Actual 26 31 26 20 2,631 150 0.557

G 3 6980-6996 Aug 66-Ene 75 20 39 62 10 3,987 190 0.600

6920-6934 Jul 92-May 02

6947-6960 Jul 92-May 02 21 36 43 4 2,866 164 0.570

G 4 7068-7082 Aug 66-Sep 74 22 64 43 10 4,455 180 0.620

7022-7039 Jul 92-May 97 22 64 43 10 4,455 180 0.620

G 6 7242-7255 Aug 66-Ene 75 24 12 30 10 4,000 190 0.600

G 402 7065-7085 Jul 99-Jul 00 28 33 49 30 3,800 190 0.570

G 404 7412-7436 Dic 00-May 01 25 25 33 201 3,751 170 0.580

G 406 7423-7436 Mar 02-Actual 18 29 49 162 3,710 169 0.570G 436 7423-7436 Mar 02-Actual 20 22 45 15 3,715 169 0.570

M 201 8413-8433 Aug 98-Actual 28 28 52 6 5,200 179 0.568

M 402 8843-8856 Sep 00-Actual 28 28 52 6 4,954 180 0.565

M 405 9637-9650 Oct 01-Actual 20 20 49 54 5,313 180 0.569

M 412 9643-9676 May 02-Actual 60 5,350 180 0.576

9545-9561 May 02-Actual 62 5,240 179 0.574

M 415 10102-10116 Jul 02-Actual 70 5,610 190 0.568

M 420 80 5,550 185 0.564

Table 1 - Reservoir and fluid data for eachproducer sandstone in the gas field.

Producer

sandstone

WellProducer

intervals

(feet subsea)

Production

time

(%)

Sw

(%)

hnet

(ft)

k

(md)

p i

(psia)

Ty

(F)g

E 3 5353-5369 Jul 92-Ago 00 22 31 39 30 2,538 150 0.558

5304-5317 Dec 99-Ago 00

E 5 5350-5383 Oct 69-Oct 00 22 31 39 30 2,631 150 0.557

E 6 5359-5373 Jul 92-Feb 01 24 30 10 30 2,538 150 0.558

E 403 5294-5320 Jul 99-Actual 27 25 52 12 2,538 150 0.558

5340-5373 Jul 99-Actual

E 405 5770-5789 Apr 01-Sep 01 28 25 23 102 2,279 150 0.557

E 406 5625-5629 Mar 02-Abr 02 25 40 7 28 2,538 150 0.558

E 412 5327-5360 May 02-Actual 26 31 26 20 2,631 150 0.557

G 3 6980-6996 Aug 66-Ene 75 20 39 62 10 3,987 190 0.600

6920-6934 Jul 92-May 02

6947-6960 Jul 92-May 02 21 36 43 4 2,866 164 0.570

G 4 7068-7082 Aug 66-Sep 74 22 64 43 10 4,455 180 0.620

7022-7039 Jul 92-May 97 22 64 43 10 4,455 180 0.620

G 6 7242-7255 Aug 66-Ene 75 24 12 30 10 4,000 190 0.600

G 402 7065-7085 Jul 99-Jul 00 28 33 49 30 3,800 190 0.570

G 404 7412-7436 Dic 00-May 01 25 25 33 201 3,751 170 0.580

G 406 7423-7436 Mar 02-Actual 18 29 49 162 3,710 169 0.570G 436 7423-7436 Mar 02-Actual


Producer

sandstone

WellProducer

intervals

(feet subsea)

Production

time

(%)

Sw

(%)

hnet

(ft)

k

(md)

p i

(psia)

Ty

(F)g

E 3 5353-5369 Jul 92-Ago 00 22 31 39 30 2,538 150 0.558

5304-5317 Dec 99-Ago 00

E 5 5350-5383 Oct 69-Oct 00 22 31 39 30 2,631 150 0.557

E 6 5359-5373 Jul 92-Feb 01 24 30 10 30 2,538 150 0.558

E 403 5294-5320 Jul 99-Actual 27 25 52 12 2,538 150 0.558

5340-5373 Jul 99-Actual

E 405 5770-5789 Apr 01-Sep 01 28 25 23 102 2,279 150 0.557

E 406 5625-5629 Mar 02-Abr 02 25 40 7 28 2,538 150 0.558

E 412 5327-5360 May 02-Actual 26 31 26 20 2,631 150 0.557

G 3 6980-6996 Aug 66-Ene 75 20 39 62 10 3,987 190 0.600

6920-6934 Jul 92-May 02

6947-6960 Jul 92-May 02 21 36 43 4 2,866 164 0.570

G 4 7068-7082 Aug 66-Sep 74 22 64 43 10 4,455 180 0.620

7022-7039 Jul 92-May 97 22 64 43 10 4,455 180 0.620

G 6 7242-7255 Aug 66-Ene 75 24 12 30 10 4,000 190 0.600

G 402 7065-7085 Jul 99-Jul 00 28 33 49 30 3,800 190 0.570

G 404 7412-7436 Dic 00-May 01 25 25 33 201 3,751 170 0.580

G 406 7423-7436 Mar 02-Actual 18 29 49 162 3,710 169 0.570G 436 7423-7436 Mar 02-Actual 20 22 45 15 3,715 169 0.570

M 201 8413-8433 Aug 98-Actual 28 28 52 6 5,200 179 0.568

M 402 8843-8856 Sep 00-Actual 28 28 52 6 4,954 180 0.565

M 405 9637-9650 Oct 01-Actual 20 20 49 54 5,313 180 0.569

M 412 9643-9676 May 02-Actual 60 5,350 180 0.576

9545-9561 May 02-Actual 62 5,240 179 0.574

M 415 10102-10116 Jul 02-Actual 70 5,610 190 0.568

M 420 80 5,550 185 0.564


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6 SPE 96829

Table 2 - Dynamic characterization results for each producing well in the gas field.

Producer

sandstone

Well

nameA (acres)

GBgi

(Bscf)Gp(Bscf) Current Fgr

E 3 328 85.6 14.3 31

E 5 213 55.5 10.0 31

E 6 815 58.7 9.8 30

E 403 38 73.6 12.3 25

E 405 38 7.9 1.2 25

G 3 898 16.8 39

235 4.3 36

G 4 909 6.8 64

G 6 366 4.1 12

G 402 34 2.5 33

G 404 189 1.6 25

M 201 245 84.6 9.0 28

M 402 343 124.4 6.9 28

M 405 494 186.5 2.7 20

Table 3 - Dynamic characterization results for each producing well in the gas field.

Producersandstone

Well name (%)

Sw(%)

hnet(ft)

k(md)

A(acres)

GBgi(Bscf)

G(Bscf)

Gp(Bscf)

CurrentFgr

E-1 3, 6, 403, 40623 27 20 30 963 138.8 23.2 13.6 58

E-2 5, 412 22 31 39 30 212 55.5 10.0 7.0 70

E-3 6 28 25 23 102 37 7.9 1.2 0.5 43

G-1 3 20 39 62 10 898 16.8

21 36 43 4 235 4.3

G-2 4 22 64 43 10 909 6.8

G-3 6 24 12 30 10 366 4.1

G-4 402 28 33 49 30 366 2.5G-5 404 25 25 33 201 189 1.6

G-6 406 18 29 49 162 0.6

G-7 436

M-1 201 28 28 52 6 245 84.6 23.6 9.2 39

M-2 402 28 28 52 6 343 124.4 33.5 6.9 20

M-3

405, 412, 415,

420 20 20 49 54 494 186.5 52.8 2.7 5


7/9

SPE 96829 7

Fig. 1 - Production history for sandstones and the field.

Gas rate( MMfcd)

SANDSTONE G

0

20

40

60

80

Dec-65 Dec-68 Dec-71 Dec-74 Dec-77 Dec-80 Dec-83 Dec-86 Dec-89 Dec-92 Dec-95 Dec-98 Dec-01 Dec-04

Gas rate( MMf cd)

0

10

20

30

40

20

40

60

80

Dec-65 Dec-68 Dec71 Dec-74 Dec-77 Dec-80 Dec-83 Dec-86 Dec-89 Dec-92 Dec-95 Dec-98 Dec-01 Dec-040

6

12

18

24

Gp (Bs

TOTAL FIELD

0

20

40

60

80


Gas rate( MMfcd)

0

25

50

75

100

Gas rate( MMfcd)

Gp (Bscf)

Gp

Gp

Gas rate

Gas rate

Gas rate

SANDSTONE E

0

20

40

60

80


6

12

18

24

Gp (Bs

Gp

Gp

Gp

Gas rate


8/9

8 SPE 96829

Fig. 2 Initial pressures for the producing wells.

Fig. 3 Seismic amplitude map and reservoirs by using dynamic characterization in the sandstone E.

D-427a

C-405

C-406

C-6

C-5C-412

C-403C-3 D-411

C-428

C-428D

C-431

C-408

Loc. Cerraz-1

C-414D

C-414

Loc. Maple -1

Loc. Joosh-1

C-402

Loc. Esprrago-1

C-416

D-419E-1

E-2

E-3

E-4

405

405

402

201

404

6

4024

33

5 6403

1500

1800

2100

2400

2700

3000

0 50 100 150 200 250 300 350 400

PRESION INICIAL (KG/CM)

PROFUNDIDAD

(M)

ARENA E

ARENA M

ARENA G

3

406

406412

GRADIENTEDEPRESIONNORMA

L

GRADIENTEDEPRESIONANORMAL

PRESION MAXIMA

ENCONTRADA

405

405

402

201

404

6

4024

33

5 6403

1500

1800

2100

2400

2700

3000

0 50 100 150 200 250 300 350 400

PRESION INICIAL (KG/CM)

PROFUNDIDAD

(M)

ARENA E

ARENA M

ARENA G

3

406

406412

GRADIENTEDEPRESIONNORMA

L

GRADIENTEDEPRESIONANORMAL

PRESION MAXIMA

ENCONTRADA

Initial pressure (kg/cm2 abs)

SANDSTONE E

SANDSTONE G

SANDSTONE M

ABNORMALPRESSUREGRADIENT

NORMALPRESSUREGRADIEN

T

MAXIMUM PRESSURE

DEPTH(METERS)


9/9

SPE 96829 9

Fig. 4 Seismic amplitude map and reservoirs by using dynamic characterization in the sandstone G.

Fig. 5 Seismic amplitude map and reservoirs by using dynamic characterization in the sandstone M.

435

4

15

102

101

201

12

418

426

427

5

10 425

405

434

424

407

415

4236

433

406

436

403

421

3

402

404

G-1

G-2

G-3G-4

G-5

G-6

G-7

2600

2800

2900 3

000

31

00

3300

3400

3500

3600

3700

3200

2700

2900

3000

3100

C-415

Loc. Clis-1

D-702

C-420

Loc. Zacamand-1

C-402

D-419 C-3

D-413a

C-201

D-416

C-412

C-405

D-409

M-1

M-2

M-3

96829-ms-p-a strategic gasfield development case in sandston

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