BrightWater

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BrightWater A Step Change in Sweep Improvement

• - What is it?
• - What isnt it?
• - Where did it come from?
• Where can it go?

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Poor Reservoir Sweep EfficiencyBypass Oil
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BrightWater can help to improve Reservoir Sweep
Efficiency, and produce the bypass Oil
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Outline

• What is BrightWater?
• How does BrightWater improve waterflood?
• Any field success?
• How to use in mature fields?
• Candidate selection
• Tests
• Implementation.
• Conclusions

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What is BrightWater

• BrightWater is a technology that improve the
  sweep efficiency of water flood by using a Novel
  robust particulate system for indepth waterflood
  conformance control
• Designed to overcome injectivity and cost
  limitations of classical polymer treatments.
  (i.e., injected as small particles then can
  become larger with time in the presence of a
  trigger - temperature)

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BrightWater History

• Contributor Involvement
• BrightWater, as a BP project, started in 1997
• It was considered as a speculative, but
  high-reward project, and was proposed as a
• Joint Venture project to the MoBPTeCh
  consortium which has now disbanded.
• Nalco was identified as best potential
  development/supply partner, and joined as equal
  contributors.
• BP
• 1998 Mobil, BP, Texaco, Chevron Nalco
• Now BP, Chevron, Nalco

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BrightWater what its not

• BrightWater material is NOT a classic viscous
  polymer
• During injection it has viscosity very close to
  water
• It cannot be damaged by shear during injection
• It is not active initially
• Totally different from conventional gel jobs.
• No CAPEX Simple to deploy

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No Capex
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What is BrightWater

• BrightWater is particles
• The median of the particle size distribution is
  about 0.3 to 0.5 microns
• BrightWater particle is supplied as a dispersion
  in hydrocarbon solvent
• The active content in the dispersion is about 30

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What is BrightWater
Bright WaterTM material is a tightly bounded,
thermally activated particle injected as a dilute
slug which flows with the water and pops open
deep in the reservoir and blocks the swept zones.
1 to 10 microns
0.1 to 1 micron
Warmth
This allows chase water to be diverted into zones
that were previously poorly swept.
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Inert BrightWater Material
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BrightWater Particles Pre-activated
Activated
This magnification is 10x greater than this one
Before Expansion Scale bar is 500 nanometers
After Expansion Scale bar is 5000 nanometers
A polymer particle which is able to propagate
through rock pores without injectivity loss
Under the influence of heat the particle expands
to a size which can block rock pore throats.
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Diluted, inert BrightWater (after injection)
Activated
Time and temperature
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5000 ppm
3900 ppm
4500 ppm
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What is BrightWater

• The injected sub-micron particles are inert
• - they give virtually no viscosity or
  adsorption
• - they are far smaller than the pores they move
  through
• The expanded particles are sticky
• - they have increased solution viscosity,
  showing they now interact with each other
• - they act to restrict water flow rate in the
  reservoir
• - the restriction can be permanent showing they
  are interacting with the porous rock

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BrightWater are Small Crosslinked polymer
particles (particle size) to propagate deep into
reservoir (pore size)
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What is BrightWater

• The time before activation can be selected
• The strength of the block can be selected
• A complete block is not usually the aim or
  necessary

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So how does BrightWater work in the reservoir?
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Usually there is a temperature front set up by
cold water injection
Temperature Front
Still at reservoir temp
Cooled by injection
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Usually there is a temperature front set up by
cold water injection
BW
Temperature Front
Still at reservoir temp
Cooled by injection
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Setting BrightWater at a temperature front
water
Temperature Front
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• Setting at a temperature front can be very
  convenient and is the ideal and usual mode for
  hot reservoirs
• But we may not need a temperature front
• We can select the grade to control the setting
  time, and set at any temperature up to 80-90C

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Setting BrightWater in an isothermal case
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• Typical treatment objectives
• Vertical conformance improvement by diverting
  water from a thief layer
• Vertical and horizontal sweep improvement by
  diverting water from a channel
• Slow down water cycling
• - allow use of increased injection
  pressure
• - allow use of increased drawdown at
  producers

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BrightWaterList of Field Trials

• Minas, Indonesia (Chevron, 2001)
• Arbroath, North Sea, UK (BP, 2002)
• Milne Point and Prudhoe Bay, Alaska, USA (BP)
  (several, 2004-5)
• Strathspey field, North Sea, UK (Chevron, 2006)
• Argentina (several, 2006)
• Pakistan (BP, 2006-7)
• Alaska (several, 2007)
• Being considered more treatments in Indonesia
  Australia, Alaska and Gulf of Mexico, USA

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Alaska Bright Water Applications
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BP Alaska Field Trial

• Trial of pattern treatment, three adjacent
  injectors, 03-13, 16-11 and 16-16 treated in 2004
  - 05
• High water cut at low to medium total Pore Volume
  injected
• Patterns mature to Miscible Injectant with
  breakthrough time 3 to 4 months

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Design Process

1. Candidate selection criteria know the
   reservoir
2. BrightWater formulation selection
3. Treatment volume and cost estimation
4. Implementation plan QA, Contingency, monitoring
5. Post treatment plan

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Characteristics of good Candidate Reservoirs

• Sandstone reservoirs
• Vertical or horizontal high permeability
  contrast, Actual sweep efficiency less than
  anticipated. Presence of bypass oil.
• Thief gt 150 md no direct interwell fractures.
• Fluid transit time between injector and producers
  gt 50 days
• Injection water temperature lower than reservoir
  temperature (Temperature gradient between
  injector and producer desired but not necessary).
• Down-hole temperature above 50 C.

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BrightWater Potential Tests desired

1. Bottle test (injection water, temperature) to
   select BrightWater formulation, if needed.
2. Sandpack Test to confirm pop time at
   temperature, if needed.
3. Interwell water breakthrough estimate field
   data tracer, pressure test - to select
   BrightWater formulation or identify area of
   potential bypassed oil, if needed.
4. Block Test (actual core material) to select
   BrightWater concentration. Needed only for very
   high or very low perm rock
5. Simple temperature model (distance between wells
   reservoir and injection water temperature, rate
   and duration of water injection) - to estimate
   thief zone temperature profile.
6. Simple reservoir model to estimate potential
   oil recovery. (Required)

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Difference between BW and Polymer
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Conclusions

• BrightWater is a new robust pre-crosslinked
  polymer particle that can expand in size at
  design temperature and time.
• There are successful field implementations
  (onshore and offshore)
• Increase oil production and recovery.
• Bullhead into injection line easily, even from a
  great distance or into subsea completion.
• No facilities upset.

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The Early stage Research team members
BP Harry Frampton Jim Morgan ChevronTexaco
Steve Cheung Rick Ng Billy Surles Les Munson
Nalco Energy Services K.T. Chang Dennis Williams
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Thank you !Questions?