Injeção de água em poços de petróleo

Injeção de água em poços de petróleo

(Parte 3 de 3)

5. Baker, R.: “Reservoir Management of Waterfloods – Part I,” 1997, JCPT.

6. Baker, R.: “Reservoir Management of Waterfloods – Part I,” January 1998, JCPT.

7. Thakur, G.C., Satter, A.: “Integrated Waterflood Asset Management,” 1998, PennWell Publishing Co.

8. SPE Reprint Series No.56: “Waterflooding,” 2003.

9. Cobb, W.M.: “Determination of Volumetric Sweep Efficiency in Mature Waterfloods using Production Data,” 1997 SPE Annual Technical Conference and Exhibition, San Antonio, TX.

10. Hall, H.N.: “How to Analyze Waterflood Injection Well Performance,” World Oil (October 1963) 128–130.

SPE 102200 7 Table 1 – Field Examples Overview

Field nameEl TrapialBangkoMeren Country ARGENTINA INDONESIA NIGERIA Onshore/Offshore Onshore Onshore Offshore

Geologic Description Sandstones Sandstones Sandstones Natural Drive MechanismSolution Gas DriveAquiferSome Aquifer - Gas Cap Permeability, mD75530700 - 10,0 Porosity, %15-182520 - 37 Oil Gravity, API373427 Oil Viscosity, cP1.14.21.5 - 2.2 Initial Pressure, psi9507702,200 - 2,600 OOIP, MMbbl 990 1,630 2,400

Injection SchemeInverted 7-SpotPeripheralPeripheral

Table 2 – Recommended Practices at Different Levels

Field Block Pattern Well

Mapping (GOR, Wcut, Pressure)x ABC Plotx Total Liquid Production vs. timexx VRR vs. Timexxx PVI vs. RFxxx PVI vs. Wcutxxx E volxx PVI / yearx Water Injection Rate vs. Target Ratex Hall Plotx

8 SPE 102200 Figures

Oil Ra te (

VRR Oil Rate

Figure 1. El Trapial field voidage replacement ratio (VRR) plot showing a direct relationship between VRR and oil rate.

Oil R ate (

VRR Oil Rate

Figure 2. Bangko field voidage replacement ratio (VRR) plot. Oil rate is not as dependant on VRR as in El Trapial field.

Oil Rat e ( M BO

VRR Oil Rate

Figure 3. Meren field voidage replacement ratio (VRR) plot.

High Wcut Low Wcut

High Wcut Low Wcut High Wcut Low Wcut

Figure 4. El Trapial field water cut (Wcut) map showing contrasting water cuts. High cuts in the south of the field and low cuts in the north.

High GOR Low GOR

High GOR Low GOR High GOR Low GOR

Figure 5. El Trapial field gas oil ratio (GOR) map showing low GORs in the southeast of the field and higher than dissolved values to the northwest of the field.

Low Pressure High Pressure

Low Pressure High Pressure Low Pressure High Pressure

Figure 6. El Trapial field static reservoir pressure map showing low values in the north of the field and higher in the south of the field.

SPE 102200 9 N

Figure 7. El Trapial field flood front bubble map showing good injection in the south and opportunities to inject more water in the north of the field as depicted by the size or radius of the 2D bubbles.

To tal L i qu id (

M bp d)

Total Liquid VRR

Maximum Facilities Capacity

Figure 8. Bangko field total liquid production.

To tal Li qui d ( M b pd)

Total Liquid VRR

Figure 9. Meren field total liquid production.

Figure 10. Benchmark between fields of recovery factor versus pore volumes injected.

Figure 1. Benchmark between fields of Water cut versus pore volumes injected.

Water rate @ Jul-03 / Water rate @ Apr-03

Oil r a te @ il r a te @

Ap

Total liquid rate decrease

Total liquid rate increase 1,1 coordinate point

Water rate @ Jul-03 / Water rate @ Apr-03

Oil r a te @ il r a te @

Ap

Total liquid rate decrease

Total liquid rate increase 1,1 coordinate point

Figure 12. “ABC” (After-Before-Compare) plot for El Trapial field, April versus July 2003 comparison.

10 SPE 102200

Figure 13. Volumetric efficiency calculation by block at economic limit for El Trapial field. Blocks colored in red and yellow are the ones with identified opportunities to improve performance of the field.

Oil Rate -

Water I n je c t io n R ate - Target W ater

In je c t io n R ate ( b ls /d

Oil Rate Target Injection Water Injection

Figure 14. Injection centered pattern type plot showing target injection rate and oil production.

Oil Rate - Tot al Li qui d Rate ( b l s / d a y )

Gas O il Ra ti o ( scf/bbl) -

Water C

Oil Rate

Total Liquid GOR

Wcut

Figure 15. Production well type plot showing oil rate, water cut, gas oil ratio.

C u m u lat ive [

Well H ead

P r essu re * T i me]

( p si* d ays)

No injectivity change Injectivity change, Injection out of zone

C u m u lat ive [

Well H ead

P r essu re * T i me]

( p si* d ays)

No injectivity change Injectivity change, Injection out of zone

Figure 16. Hall plot examples. Black dashed line case well shows no change in injectivity. Red dashed line case well suffered corrosion problems that caused injectivity out of zone.

Figure 17. Location of El Trapial field waterflood optimization pilot. Pattern configuration consisted of a confined area with four inverted seven spot patterns.

Oil Rate - T otal L i q u id

R ate ( b ls /d

200% Total Liquid Rate

Oil Rate VRR

Pilot Start Figure 18. El Trapial field reliability pilot project results.

(Parte 3 de 3)

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