Oilgen on Low Salinity AFES 9 Nov 2011
Transcript of Oilgen on Low Salinity AFES 9 Nov 2011
7/27/2019 Oilgen on Low Salinity AFES 9 Nov 2011
http://slidepdf.com/reader/full/oilgen-on-low-salinity-afes-9-nov-2011 1/17
Low Salinity water injection:
Evaluating the EOR potential
Presentation at the
Aberdeen Formation EvaluationSociety
9 November 2011
Laurent Schirrer, Oilgen Ltd
7/27/2019 Oilgen on Low Salinity AFES 9 Nov 2011
http://slidepdf.com/reader/full/oilgen-on-low-salinity-afes-9-nov-2011 2/17
Motivation: a “forum” more than a
formal presentation
Presentation»
Raise awareness on Low Salinity water injection as anEOR technique
» Practical workflows now exist to evaluate commercialfeasibility
» Specific Challenges for the North Sea
Please interrupt (for clarification only, thank you)
Questions / AnswersWhere the value is added
Followed by: AFES social drinks
Where the value is destroyed ?
AFES November 2011 - Aberdeen
7/27/2019 Oilgen on Low Salinity AFES 9 Nov 2011
http://slidepdf.com/reader/full/oilgen-on-low-salinity-afes-9-nov-2011 3/17
Presenter
Laurent SCHIRRER
» Director of Oilgen Ltd, a reservoir engineeringand subsurface consultancy
» Background in Reservoir Engineering,
Geoscience management, Development» Low Salinity ?
In 2010-2011, consultant subsurface leader on a NorthSea EOR Low Salinity evaluation project
AFES November 2011 - Aberdeen
7/27/2019 Oilgen on Low Salinity AFES 9 Nov 2011
http://slidepdf.com/reader/full/oilgen-on-low-salinity-afes-9-nov-2011 4/17
What is Low Salinity water
injection ?
The injection of water of a salinity lower thanthe formation water,for the purpose of
increased oil recovery,either in secondary or
tertiary mode
…when the Enhanced Oil
Recovery (EOR) effectis genuinely caused by
the reduction insalinity
0
5000
10000
15000
20000
25000
30000
35000
Formation
Water
Injection Water Low Salinity
Water
m g / l
Water salinity
TDS
0
200
400
600
800
1000
1200
1400
Formation
Water
Injection Water Low Salinity
Water
m g / l
Divalent Cations
Ca++
Mg++
Example: reduction in salinity
and main divalent cationconcentrationAFES November 2011 - Aberdeen
7/27/2019 Oilgen on Low Salinity AFES 9 Nov 2011
http://slidepdf.com/reader/full/oilgen-on-low-salinity-afes-9-nov-2011 5/17
History, breakthrough
1967: Bernard» “Effects of Floodwater Salinity on Recovery of Oil
from Cores containing Clays”
1995: Morrow, investigative work 2004: first SWCTT; 2008: first inter-well (BP,
SPE129692) 2005: LoSal™ trademark filed by BP
» IP rights on “brand” reflects commercial focus
2011: North Sea» Clair Ridge, Statoil work (Heidrun, Snorre)
+ many more, involuntary, secondary mode, trials…
AFES November 2011 - Aberdeen
7/27/2019 Oilgen on Low Salinity AFES 9 Nov 2011
http://slidepdf.com/reader/full/oilgen-on-low-salinity-afes-9-nov-2011 6/17
Wettability changes cause the EOR
effect
Consensus
» The effect is genuinelyattributed to thereduction in salinitycompared to formationwater
» Low Salinity waterinduces a change of rock affinity towardswater (more water-wet)
» Published, convergingevidences, e.g. ShellSPE129564
Implications
» The more oil-wetinitially, the better
» Is it why it works betterin secondary mode ?
AFES November 2011 - Aberdeen
1.0000, 0.00001.0000, 0.00000.0000
0.1000
0.2000
0.3000
0.4000
0.5000
0.6000
0.7000
0.8000
0.9000
1.0000
0.0000 0.2000 0.4000 0.6000 0.8000 1.0000
R e l a t i v e P e
r m e a b i l i t y
Water Saturation
Improved fractional flow towards more water-wet
Kro Oil Wet tending
Krw Oil Wet tending
Kro Water Wet tending
Krw Water Wet tending
7/27/2019 Oilgen on Low Salinity AFES 9 Nov 2011
http://slidepdf.com/reader/full/oilgen-on-low-salinity-afes-9-nov-2011 7/17
…though, underlying mechanisms
yet unresolved
Multiple Ion Exchangemechanism (BP)» Lager, 2006» Reduction in divalent
cation break theequilibrium of Electrical Double
Layer, releasingadsorbed oil
Acid/Base reactions
» Tor Austad, Univ. of Stavenger 2010
» In acidic conditions,Ca++ desorbs, A/Breactions release
adsorbed oil
Others» Boussour, Total & Univ. of Bordeaux,
2009: “…counter examples for mostof proposed mechanisms”
» Historically: fines migration, pH» Current research focuses on clays
adsorption, EDL evidence,…» Nearly ALL agree that EOR originates
from change in surface properties of clays (original oil produced fromchange in wettability)
AFES November 2011 - Aberdeen
7/27/2019 Oilgen on Low Salinity AFES 9 Nov 2011
http://slidepdf.com/reader/full/oilgen-on-low-salinity-afes-9-nov-2011 8/17
Published field evidence
BP» Endicott (Alaska)» Core tests, Single-Well Chemical Tracer tests (SWCTT),
first inter-well pilot» Excellent agreement between core results and field
results
Shell» Changes of wettability on the field of Omar in Syria,following the injection of ground-water
Statoil» Snorre: good agreement between core tests and
SWCTT, though… negative» Recent press-releases on potential tests ongoing on the
Heidrun field
AFES November 2011 - Aberdeen
7/27/2019 Oilgen on Low Salinity AFES 9 Nov 2011
http://slidepdf.com/reader/full/oilgen-on-low-salinity-afes-9-nov-2011 9/17
0.000
0.020
0.040
0.060
0.080
0.100
0.120
0.140
0.160
0.180
0.200
0 0.2 0.4 0.6 0.8 1 1.2
I n c r e m e n t a l R e c e o v e
r y ( F r a c O O I P )
Water salinity (1=Formation Water)
From SPE 93903, mod. L.S
Core Flood
SWCTT
So simple…
(on a system that works)
AFES November 2011 - Aberdeen
Apparenttrigger is:divalent
cation lessthan FW
7/27/2019 Oilgen on Low Salinity AFES 9 Nov 2011
http://slidepdf.com/reader/full/oilgen-on-low-salinity-afes-9-nov-2011 10/17
Factors controlling the “Low
Salinity” effect
A set of favourableconditions
» ROCK/RESERVOIR
Presence of clays inmatrix
Some better than others
Tending “Oil wet” High Sor (in situ)
» OIL
Heavy, polar components
» WATER
Salinity less than FW
Less divalent cation
No definite deterministicfactors yet identified
“Screening” helps
Simulation on standardblack oil
Core experiment necessaryto conclude
AFES November 2011 - Aberdeen
7/27/2019 Oilgen on Low Salinity AFES 9 Nov 2011
http://slidepdf.com/reader/full/oilgen-on-low-salinity-afes-9-nov-2011 11/17
7/27/2019 Oilgen on Low Salinity AFES 9 Nov 2011
http://slidepdf.com/reader/full/oilgen-on-low-salinity-afes-9-nov-2011 12/17
North Sea or Offshore specifics
Cost of field trials “pilot” phase
Facilities» Footprint, weight of RO and water equipment
» Logistics, planning
» Cost
Environmental
» Saline water discharge probably the only
negative
AFES November 2011 - Aberdeen
7/27/2019 Oilgen on Low Salinity AFES 9 Nov 2011
http://slidepdf.com/reader/full/oilgen-on-low-salinity-afes-9-nov-2011 13/17
Technical evaluation of Low
Salinity potential
Integrated project
Sub-surface intensive
Formation Evaluation & Core Analysis playmain role
AFES November 2011 - Aberdeen
Screening Feasibility Pilot
a.k.a. … Pre-feasibility, Appraise Concept-Selection of pilot
phase
Phase 1
Implementation
Scope "Score": Reservoir, Oil,Brine. Litterature review
Corefloods, reservoirsimulation, facilities and
development engineering,
logistics, supply chain
Prove in-situ effect,calibrate models
Drivers Screen "wide", Integration Quality, protocols, expertise,
think economics of full project,
Inte rated Team
Acquire data for final
design
Synergies Formation damage, scalemanagement
Surfactants/P, desulfatation,low salinity as a commodity, …
7/27/2019 Oilgen on Low Salinity AFES 9 Nov 2011
http://slidepdf.com/reader/full/oilgen-on-low-salinity-afes-9-nov-2011 14/17
Low Salinity vs EOR alternatives
Clean Low cost
Synergies with ASP, Polymers
Gas injection,
MGI, WAG,
Segregated
CO2 ASP Polymers
A priori uncertainties
Applicability
Evaluation cost
EOR effect
Logistics / Supply
Capex / facilities
Capex / wellsOpex
Safety / Environment
Synergies ? YES YES
Low Salinity's
Advantage
Neutral
Handicap
AFES November 2011 - Aberdeen
7/27/2019 Oilgen on Low Salinity AFES 9 Nov 2011
http://slidepdf.com/reader/full/oilgen-on-low-salinity-afes-9-nov-2011 15/17
North Sea Outlook
Inventory of North Sea potential ?
» Narrow base of field candidates» Technical intelligence
» Projects funding ?
Incentives, make EOR competitive» Longer pay-back times compared to “conventional”
projects
» Yet clean and sustainable technique
» Existing schemes vs further tax breaks ?
Freshwater as a commodity» Ageing facilities, footprint, power requirement…
AFES November 2011 - Aberdeen
7/27/2019 Oilgen on Low Salinity AFES 9 Nov 2011
http://slidepdf.com/reader/full/oilgen-on-low-salinity-afes-9-nov-2011 16/17
Conclusion
Low Salinity water injection is a specific EOR method» Efficient for a set of reservoir “settings” and fluid “conditions”
» Not yet a deterministic science, but continuously improving Commercial feasibility through experimental programme
» High-tech, integrated, multi-discipline» “Supply” of competences exist» A priori chances of success not yet in “comfort zone”
Everyone likes Low Salinity (…if or when it works)» Environmentally friendly» Low operating costs» Synergies: Surfactants, Polymers, De-sulfatation
Focus areas for a North Sea take-off » 1- Map subsurface potential» 2- Incentives» 3- Facilities…(in this order)
AFES November 2011 - Aberdeen
7/27/2019 Oilgen on Low Salinity AFES 9 Nov 2011
http://slidepdf.com/reader/full/oilgen-on-low-salinity-afes-9-nov-2011 17/17
Thank you To the “Low Salinity” scientific community
for their efforts in publishing and sharing
information, allowing us to envisagecommercial applications at earliest
To the AFES for giving us the opportunityto present on this interesting andpromising technique
Oilgen Ltd48 Queens Road AberdeenAB15 4YE
T: +44 1224 327047E: [email protected]: www.oilgen.com