BrightWater® – A Step Change in Sweep Improvement - What is it? - What isn’t it? - Where did it come from? Where can it go?

Poor Reservoir Sweep Efficiency Bypass Oil

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

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

What is BrightWater® BrightWater is a technology that improve the sweep efficiency of water flood by using a Novel robust particulate system for in–depth 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)

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

BrightWater® – what it’s 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

No Capex BW Particulate Dispersant ½” NPT fitting to be used for EC9368A injection ½” NPT fitting to be used for EC9360A injection Well Head Well House Floor 2” Well Line Dispersant BW Particulate

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%

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. 0.1 to 1 micron 1 to 10 microns Warmth This allows chase water to be diverted into zones that were previously poorly swept.

Inert BrightWater Material

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.

Diluted, inert BrightWater (after injection) Activated Time and temperature

5000 ppm 3900 ppm 4500 ppm

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

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

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

So how does BrightWater work in the reservoir?

Still at reservoir temp Cooled by injection Usually there is a temperature front set up by cold water injection Temperature Front Still at reservoir temp Cooled by injection

Still at reservoir temp Cooled by injection Usually there is a temperature front set up by cold water injection BW Temperature Front Still at reservoir temp Cooled by injection

Setting BrightWater at a temperature front

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

Setting BrightWater in an isothermal case

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

BrightWater List 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

Alaska Bright Water Applications

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 The FS2 Trial consisted of 3 patterns. 03-13, 16-11, and 16-16. These are in the south east portion of Prudhoe and isolated on the north by a fault, truncation on the east, and edge of the field on the south.

Design Process Candidate selection : criteria; know the reservoir BrightWater formulation selection Treatment volume and cost estimation Implementation plan : QA, Contingency, monitoring Post treatment plan Looking through our files we noted that many of the gaps were similar among the reviewed projects, so sorted them into bins with common themes and called them “high level lessons learned”. One common theme was, “Projects that participated in Planning Assists were better prepared for their Subsurface Technical Reviews. Next numerous projects thought that the term alternatives applied to surface facilities only and therefore generated only one development alternative with one set of production profiles. Many project’s Subsurface “front-end loading” efforts are compromised by very aggressive project schedules and/or insufficient resources. Also, too often Projects do not allow enough time or resources to implement the Review Team’s critical suggestions before their next phase gate. And in a few cases, the recovery estimates and forecasts were based on inappropriate reservoir models.

Characteristics of good Candidate Reservoirs Sandstone reservoirs Vertical or horizontal high permeability contrast, Actual sweep efficiency less than anticipated. Presence of bypass oil. Thief > 150 md; no direct interwell fractures. Fluid transit time between injector and producers > 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.

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

Difference between BW and Polymer

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.

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

Thank you ! Questions?