Friday Ppt

1SPE

EOR Screening: A laboratory Investigation to compare the performance of WAG and SAG processes for an Indian Field

Presented By Neha Surya B.tech IVth Year RGIPT , Rae Bareli

3/2/2012

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Where are the resources ? Mature Fields

How will we obtain them?Enhanced Oil Recovery(EOR)

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Contents

Water Alternate Gas(WAG) Process

Surfactant

Alternate Gas(SAG) Process

Laboratory

Studies

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WAG Process Water Alternating Gas Process : Type of EOR Microscopic displacement efficiency of Gas + Macroscopic sweep efficiency of water Incremental recovery :- 6 % -16 %. Difference in results between experimental

investigations and practical implementation on reservoir scale

Gases used :- CO , N , HC gases, Mixture of ₂ ₂different gases.3/2/2012

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WAG Started…

Proposed by Claudle & Dyes in 1958

Pilot in the North Pembina (Alberta,Canada)

Majority of fields in former USSR

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Process

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WAG Process Classification General Classification

on the basis of Cycle size Single cycle WAG Five cycle WAG Tapered WAG

Other forms are hybrid WAG & Simultaneous Water Alternate Gas (SWAG) process.

WAGMiscible

First contact

Multi contact

Immiscible

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Design Parameters Reservoir heterogeneity Rock & Fluid Interactions Injection Gas Characteristics Injection Pattern Tapering Slug size Cycle Size WAG Ratio Gravity Considerations in WAG

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Screening Criteria Minimum oil saturation : 25-30% Reservoir :- Homogeneous enough to minimize fingering . As CO corrosive in nature, it must be taken care of.₂ Ratio of water and gas. Moderately light to light oil reservoirs(API gravity > 25˚). The reservoir should be deep enough to contain the MMP.

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Associated Problems

Some of the operational problems are:-

Early Breakthrough in production wells Reduced Injectivity Corrosion Formation of scale, asphaltene,hydrates etc. Different temperatures of injected phase

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Surfactant Alternate Gas(SAG)

Immiscible gas injection process . mobility control to improve sweep efficiency. foam can be injected into the reservoir by injecting

alternate slugs of surfactant solution and gas. First proposed in 1958 by Bond & Hole brook. Main factor contributing towards incremental disp.

efficiency on entrapment of gas due to hysteresis and the effect of 3 phase flow.

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Laboratory Studies

Micro Activity

Planning

Collection of reservoir rock &

fluid samples

Core cutting ,extraction

and drying of cores

Preparation of core sand pack & evacuation

PV & HCPV determinationSaturation with live

oil Different experimental procedures

Data Interpretation

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Experimental Set up

Positive Displacement Pump Buffer Cell Rocking Cell Hot Air Oven Measuring Cylinder Gas Meter

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Experimental study

Intended to suggest the best EOR scheme for an Indian field.

Aimed at evaluating the performance of WAG (single cycle and five cycle) and SAG injection in the core as a function of displacement efficiency by injectant to improve oil recovery.

Effect of CO2 on crude oil if injected as WAG mode.

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Procedure

Saturation of Core Pack with Live Oil. Water flooding of the core pack @ 10cc/hr. Start of WAG injection. Slug size of WAG was calculated. WAG injection was started @ 5cc/hr (gas) & @ 10

cc/hr (water). Chasing up fluid( water). Cleaning & Drying of core pack.

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Exp. No.1 : Five Cycle WAGFlood type Cum.

WaterInjected (cc)

Cum. Water Produced (cc)

Cum. Oil Produced (cc)

Reservoir Oil Volume (cc)

Connate Water (cc)

Water Flood 36.9 15.0 12.5 23.00 14.4

G-1 36.9 18.0 13.0 23.92 14.4

W-1 41.4 21.5 13.0 23.92 14.4

G-2 41.4 25.5 13.0 23.92 14.4

W-2 45.9 31.0 13.0 23.92 14.4

G-3 45.9 33.5 13.5 24.84 14.4

W-3 50.4 37.0 13.5 24.84 14.4

G-4 50.4 41.0 13.5 24.84 14.4

W-4 54.9 45.0 13.5 24.84 14.4

G-5 54.9 48.0 14.0 25.76 14.4

W-5 59.4 50.0 14.0 25.76 14.4

Chase Water

64.5 53.0 14.0 25.76 14.4

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0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.000

10

20

30

40

50

60

70

80

WAG(5 Cycle)

PV Injected

Dis

pla

cem

ent

Eff

icie

ncy

(%

)

Water Flood 5-Cycle WAG CW

Tertiary Recovery: 7.46%

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0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 20

10

20

30

40

50

60

70

80

Fluid Saturation during 5 cycle WAG

Sw(%) Sg(%) So(%)

PV Injected

Sw

, S

g,

So

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0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.40

10

20

30

40

50

60

70

Single Cycle WAG Injection

PV Injected

Dis

pla

cem

ent

effi

cien

cy (

%)

Water Flood

Gas

Tertiary Recovery =7.2%

Water CW

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Exp. No.3 : Five Cycle SAG Surfactant (sulphodet L-38) solution having its concentration of

2000 ppm is used.

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Flood Type

Cum. WaterInjected(cc)

Cum. WaterProduced(cc)

Cum. OilProduced(cc)

Res. OilVol.(cc)

Connate Water Vol.(cc)

WF 43.60 20.50 12.5 23.00 13.40

G-1 43.60 22.00 13.0 23.92 13.40

S-1 48.10 25.00 13.0 23.92 13.40

G-2 48.10 27.00 13.5 24.84 13.40

S-2 52.60 30.00 13.5 24.84 13.40

G-3 52.60 33.00 14.0 25.76 13.40

S-3 57.10 37.00 14.0 25.76 13.40

S-4 57.10 40.00 15.0 27.60 13.40

S-4 61.60 44.00 15.0 27.60 13.40

G-5 61.60 48.00 15.0 27.60 13.40

S-5 66.10 50.00 15.0 27.60 13.40

CW 86.90 63.00 15.0 27.60 13.40

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0.00 0.50 1.00 1.50 2.00 2.500

10

20

30

40

50

60

70

80SAG(5 Cycle)

PV Injected(cc)

Dis

pla

cem

ent

Eff

icie

ncy

(%)

Water Flood SAG

CW

Tertiary Recovery: 12.62Incremental Recovery: 5.15%

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0 0.5 1 1.5 2 2.50

10

20

30

40

50

60

70

80

Fluid Saturation during SAG (5 Cycle)

Sw Sg So

PV Injected

Sw

, S

g,

So

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Exp. No. 4: Five Cycle WAG (CO₂)Flood Type

Cum.Water Injected(cc)

Cum.Water Produced(cc)

Cum.OilProduced(cc)

Res. OilVolume(cc)

Connate Water Vol. (cc)

WF 29.40 11.50 11.50 21.16 12.86

CO₂-1 29.40 12.00 11.50 21.16 12.86

Water-1 33.90 12.00 12.00 22.08 12.86

CO₂-2 33.90 18.50 13.00 23.92 12.86

Water-2 38.40 22.00 13.50 24.84 12.86

CO₂-3 38.40 26.00 13.50 24.84 12.86

Water-3 42.90 30.00 14.00 25.76 12.86

CO₂-4 42.90 34.00 17.00 31.28 12.86

Water-4 47.40 37.00 17.00 31.28 12.86

CO₂-5 47.40 41.00 18.00 33.12 12.86

Water-5 51.90 43.00 19.00 34.96 12.86

Chase water 56.90 46.00 19.00 34.96 12.863/2/2012

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0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.800

20

40

60

80

100

120

WAG (CO₂) Five Cycle

PV Injected (cc)

Dis

pla

ce

me

nt

Eff

icie

nc

y (

%)

Water Flood CO₂ WAG

Tertiary Recovery: 37.81%Incremental Recovery: 30.35%

CW

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Results

Five Cycle WAG

Single Cycle WAG

Five Cycle SAG Five Cycle CO₂ WAG

0

10

20

30

40

50

60

70

80

90

100

Recover(WF)

Tertiary Re-covery

Total Recovery

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Results continued…

Five Cycle WAG

Single Cycle WAG

Five Cycle SAG

Five Cycle CO₂ WAG

0

0.5

1

1.5

2

2.5

3

3.5

PV inj upto WFPV inj after WFTotal PV inj

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Conclusions Recoveries should be normalized by the amount of gas

injected to enable direct comparisons and get reliable results.

WAG injection in cyclic mode gives better result. The entrapment of gas due to hysteresis & the effect of

the 3 phase flow further contribute to increase recovery by injecting immiscible gas in SAG manner.

CO became miscible with the oil at the reservoir pressure ₂of 240 kg/cm² and hence the residual oil saturation became very less.

CO WAG can prove to be profitable in India if we can ₂have CO generated from different sources.₂

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Acknowledgement

Sincere thanks to• Mr.Laxminarayan Mahli, Manager (Reservoir), IRS,

ONGC , Ahmedabad

• Dr. U.S Prasad, Professor, RGIPT, Rae Bareli

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References Enhanced Oil Recovery, Fundamentals & Analyses-E.C. Donaldson, G.

V. Chilingarian, T.F.Y En A Thesis on Immiscible & Miscible Gas-Oil Displacements In Porous Media by

Madhav M.kulkarni . Effect Of Oil & Flue Gas Composition On Oil recovery In The Flue Gas/Light Oil

Injection Processes - O.S. Shokoya, Spe, Shell Canada, And S.A. Mehta, Sspe , R.G. Moore ,Spe , And B. Maini, Spe, University Of Calgary, Canada.

Promise and Problems of Miscible-Flood Enhanced Oil Recovery, The Need for Surfactant-Based Sweep and Mobility Control by Duane H. Smith Enhanced Oil Recovery Group, Morgantown Energy Technology Center, U.S. Department of Energy, Morgantown, WV 26507-0880.

Enhanced Oil Recovery & CCS by L.D. Carter

Article Alley - Fortune Oil and Gas Willis Texas Offers The Story Enhanced Oil, an article by Jim Knight3/2/2012

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References continued… EOR Economics What Works and What Doesn’t by Oswald Clint, Ph.D., ACA , Senior

Analyst , +44-207-170-5089 • [email protected] Enhanced Oil Recovery By Water Alternating Gas (WAG) Injection by D. H. Tehrani, A.

Danesh, M. Sohrabi And G. Henderson, Department Of Petroleum Engineering, Heriot-Watt University Edinburgh, Uk.

Surfactant-Alternate-Gas (SAG) Injection Process as a Novel EOR Technique-- A

Laboratory Investigation. Category: Reservoir Modeling and Characterisation by J. P. Srivastava,

D. S. Negi, Adarsh K. Jain, and Dr. A. K. Dhawan, IRS, ONGC, Ahmedabad. Enhanced oil recovery by gas injection : Proposed Screening criteria by F.B Thomas,

D.B Bennion, X.L Zhou , a. Erian, D.W Bennion , Hycal energy laboratories Ltd.

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Thank You !!!

Any questions

3/2/2012