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Field Case Study #3 Implementation of Low Salinity Waterflooding Mike Singleton Flow Assurance & Scale Team: Scale Workshop Treetops Hotel, Aberdeen, 29 January 2019

Field Case Study #3 Implementation of Low Salinity ... · Field Case Study #3 Implementation of Low Salinity Waterflooding Mike Singleton Flow Assurance & Scale Team: Scale Workshop

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Page 1: Field Case Study #3 Implementation of Low Salinity ... · Field Case Study #3 Implementation of Low Salinity Waterflooding Mike Singleton Flow Assurance & Scale Team: Scale Workshop

Field Case Study #3

Implementation of Low Salinity

Waterflooding

Mike Singleton

Flow Assurance & Scale Team: Scale Workshop

Treetops Hotel, Aberdeen, 29 January 2019

Page 2: Field Case Study #3 Implementation of Low Salinity ... · Field Case Study #3 Implementation of Low Salinity Waterflooding Mike Singleton Flow Assurance & Scale Team: Scale Workshop

2

Background

Low Salinity Waterflooding has been shown

in some cases to increase recovery by ~16%

compared to “High Salinity” case

Cum.

Oil

(% OOIP)

100

PV injected

High salinity (FW)

Low salinity

1 2 3

Cum.

Oil

(% OOIP)

100

PV injected

High salinity (FW)

Low salinity

1 2 3

Effect of low salinity on cumulative oil recovery profiles; brine injection in

a clay-bearing core conditioned with crude oil (after Tang and Morrow, 1996).

Page 3: Field Case Study #3 Implementation of Low Salinity ... · Field Case Study #3 Implementation of Low Salinity Waterflooding Mike Singleton Flow Assurance & Scale Team: Scale Workshop

3

Background

Work undertaken for BP under FASTrac –

Commercial activity of FAST

Series of detailed Core Flood experiments

performed

Supplemented by pore scale network

modelling

Results from which contributed to full field

implementation of Low Salinity Waterflooding

in Clair Ridge

Page 4: Field Case Study #3 Implementation of Low Salinity ... · Field Case Study #3 Implementation of Low Salinity Waterflooding Mike Singleton Flow Assurance & Scale Team: Scale Workshop

4

Study at HWU - Laboratory

Series of detailed Core Flood experiments

performed

Focus on factors controlling increased

recovery

• Brine – Rock – Oil interactions

Reservoir conditioned core floods

• Oil recovery

• Full effluent analysis

– brine composition by ICP analysis

- pH

Page 5: Field Case Study #3 Implementation of Low Salinity ... · Field Case Study #3 Implementation of Low Salinity Waterflooding Mike Singleton Flow Assurance & Scale Team: Scale Workshop

5

Core Flooding

Salinity transition from 35,000mg/l (High)

to 1,000mg/l (Low)

Full effluent analysis – pH, [Ca2+], [Mg2+]

Oil Recovery

Page 6: Field Case Study #3 Implementation of Low Salinity ... · Field Case Study #3 Implementation of Low Salinity Waterflooding Mike Singleton Flow Assurance & Scale Team: Scale Workshop

6

Results

Page 7: Field Case Study #3 Implementation of Low Salinity ... · Field Case Study #3 Implementation of Low Salinity Waterflooding Mike Singleton Flow Assurance & Scale Team: Scale Workshop

7

Matching Experimental Data by Ion

Exchange

0

5000

10000

15000

20000

25000

30000

35000

0

5

10

15

20

25

30

0 10 20 30 40 50 60 70N

a+ C

on

cen

trat

ion

Ca+

+, K

+, M

g++

con

cen

trat

ion

, pp

m

Injected Pore Volumes

GEM VS PHREEQ-C VS EXPERIMENTAL DATA

Ca+ Lab

Ca++ 20 CELLS - CEC 350 STCH0.12Ca++ Phreeq-C

K+ Lab

K+ 20 CELLS - GEM CEC 350STCH 0.12K+ Phreeq-C

Mg++ Lab

Mg++ 20 CELLS - GEM CEC 350STCH 0.12Mg++ Phreeq-C

GEM

PRHEEQ-C

Page 8: Field Case Study #3 Implementation of Low Salinity ... · Field Case Study #3 Implementation of Low Salinity Waterflooding Mike Singleton Flow Assurance & Scale Team: Scale Workshop

8

Results

Multi-component ion exchange (MIE)

Where …

1. MIE => leads to a “self freshening” zone (low Ca, Mg)

2. Within this zone double layer expansion occurs (DLVO)

3. Mixed –wet system becomes SLIGHTLY more water-wet

Page 9: Field Case Study #3 Implementation of Low Salinity ... · Field Case Study #3 Implementation of Low Salinity Waterflooding Mike Singleton Flow Assurance & Scale Team: Scale Workshop

Pore Network Model Representations of Porous Media

Quasi-static (capillary dominated) displacement

physics described by Y-L equation 2 .cos ow

cPr

Pore Scale Modelling

Page 10: Field Case Study #3 Implementation of Low Salinity ... · Field Case Study #3 Implementation of Low Salinity Waterflooding Mike Singleton Flow Assurance & Scale Team: Scale Workshop

Figure 16: Phase occupancy of the remaining oil for the low salinity (LS)

water flood in a “mixed wet large” (MWL) system.

1 1 2 2

1 2

2 2. .cos . .cosow ow ow ow

R R

2

1

1ow

ow

2

1

1cos

cos

ow

ow

THUS …

2 2

2 1

1 1

cos.

cos

ow ow

ow ow

R R

Sor (HS)

Pore Scale Modelling

Page 11: Field Case Study #3 Implementation of Low Salinity ... · Field Case Study #3 Implementation of Low Salinity Waterflooding Mike Singleton Flow Assurance & Scale Team: Scale Workshop

0

0.002

0.004

0.006

0.008

0.01

0.012

0.014

0.016

0.018

0.02

0 20 40 60 80 100

Pore size, r -->

PS

D,

f(r)

R1 = 54 mRw = 40 m

R2 = 45.3 m

Sor = 0.274

Sor = 0.168

Rw

Calc.

R1

Calc.

Sor

Calc.

R2 Sor

%inc.

oil

(mm) (mm)

40 54 0.274 45.3 0.169 61.7

50 65 0.338 54.5 0.239 70.7

60 100 0.492 83.9 0.079 16.1

Assume in oil wet pores:

ow HS = 140o ow LS = 130o

HS : cos 140o = -0.766

LS : cos 130o = -0.6436

Pore Scale Modelling

Page 12: Field Case Study #3 Implementation of Low Salinity ... · Field Case Study #3 Implementation of Low Salinity Waterflooding Mike Singleton Flow Assurance & Scale Team: Scale Workshop

12

Results

Building on Multi-component ion exchange (MIE)

Where …

1. MIE => leads to a “self freshening” zone (low Ca, Mg)

2. Within this zone double layer expansion occurs (DLVO)

3. Mixed –wet system becomes SLIGHTLY more water-wet

4. Consequence of changes of ow are LARGE in Sor

according to simple pore-scale model (Pc,HS = Pc,LS)

Page 13: Field Case Study #3 Implementation of Low Salinity ... · Field Case Study #3 Implementation of Low Salinity Waterflooding Mike Singleton Flow Assurance & Scale Team: Scale Workshop

13

Outcome

“[This work] has made a significant contribution

to the fundamental understanding of the

mechanism by which Low Salinity Water

Flooding increases oil recovery. Without such

understanding and contribution, BP would not

be in a position to change their Water Flood

strategy to a default base case position of Low

Salinity Water Flooding."

BP’s Chief Adviser on Low Salinity