Cyclic Steam Stimulation in Alberta Tar Sands Case study: ExxonMobil Cold Lake Nabiye Tar oil project Odunlami Adefisayo PTE 531 Fall 2016

Presentation Outline Project Objective Introduction Cyclic Steam Stimulation Performance Facilities design Pros, Cons, and Main Challenge CSS case study on Alberta Cold lake Tar Sand References

Project Objective Canadian Tar sand contains a high viscous black oil known as bitumen. The bitumen has no mobility and cannot be produced in its natural states thus heating the reservoir to reduce the viscosity is very critical in tar sand oil production. http://geology.com/articles/oil-sands/ "http://www.oilsandsmagazine.com/oil-sands-deposit/"

Project Objective During Cyclic Steam Stimulation, steam is injected into the reservoir to reduce the bitumen viscosity, increases oil mobility, and drives the low viscous bitumen to the wellbore for production Viscosity (Vertical axes) reduces with Temperature (Horizontal axes) Current Overview of Cyclic Steam Injection Process Johannes Alvarez*1, Sungyun Han*2

Introduction Tar sands contain almost 10% of global proven reserves There is a need for unconventional reserves development as proved conventional reserves decreases and oil demand increases "http://www.oilsandsmagazine.com/oil-sands-deposit/"

Introduction Largest Tar Sands Reserves in the world Alberta Canada Athabasca Cold lake Peace River Orinoco Venezuela http://geology.com/articles/oil-sands/

Introduction CSS has a low recovery factor compared to other EOR method The low recovery factor is compensated by lower CAPEX and OPEX Economically proven Tertiary EOR method Current Overview of Cyclic Steam Injection Process Johannes Alvarez*1, Sungyun Han*2

Cyclic Steam Injection https://www.netl.doe.gov/file%20library/research/oil-gas/enhanced%20oil%20recovery/colcyclic_stm.pdf

Cyclic Steam Injection The objectives of CSS are: Use steam to heat the cold tar sand Reduce oil viscosity Pressure up the reservoir and Fracture into new sand with each steam cycle Mobilize new bitumen to the wellbore every steam cycle

Cyclic Steam Injection Stage 1: Stimulation phase. Steam is injected into the reservoir for several days/days depending on the size of the reservoir Stage 2: Soak phase. Steam injected is stopped and the reservoir is allowed to soaked. Bitumen viscosity is reduce and moves to the wellbore. Stage 3: Production phase. The less viscous bitumen and condensate are pumped to the surface.

Cyclic Steam Injection Also called "Huff and Puff" Method Huff phase is when steam is injected Puff phase is when heated bitumen is produced along with condensate The process is repeated when production becomes uneconomical.

Case Study: ExxonMobil Cold Lake Nabiye Tar oil project Cold Lake Reservoir and Fluid Properties: Thick unconsolidated sand Producing zone at 1,500 ft TVD Very Heavy oil: 11 API Very Viscous oil: 75,000 cp Net Pay: approximately 115 ft Porosity: 35%

Case Study: ExxonMobil Cold Lake Nabiye Tar oil project Located 85 miles northeast of Edmonton, Alberta, Canada Largest North America in-situ operation Average daily production: 150,000 barrels of bitumen per day Recoverable oil: 280 million barrels of oil Expected Lifespan: 30 years (Scheduled to be abandoned in 2045)

Case Study: ExxonMobil Cold Lake Nabiye Tar oil project Recent Expansion in 2015 $2 billion expansion to increase production by 40,000 barrels per day E. Vlttoratos, SPE, Oeorge R. Scott, and Craig I. aeattle, SPE, Esso Resources Canada ltd. Reservoir Simulation of Steam Injection in the Cold Lake Tar Sand by W.T. Peake, SPE Member

CSS Facilities at Cold Lake The same wellbore is used for both injection and production http://www.imperialoil.com/Canada-English/Files/Cold_Lake_Expansion_Project_Volume1.pdf

Benefits of CSS Application in Tar Sand Reserves Reserves are located in low political risk location (Canada) compare to Middle East Economically feasibly reserves with advancing technology Less surface footprint and low environmental impact Less CAPEX and OPEX compare to other EOR methods

Cons of CSS Application in Tar Sand Reserves Pollutes underground water Requires lots of water for steam production Injection inefficiency due inter well interaction during CSS

Main Challenge Interwell Communication- The most expensive Operating cost of CSS is from steam production. Thus, interwell communication is a major issue that determines the profitability of CSS project. E. Vlttoratos, SPE, Oeorge R. Scott, and Craig I. aeattle, SPE, Esso Resources Canada ltd.

References Johannes Alvarez, Sungyun Han "Current Overview of Cyclic Steam Injection Process" E. Vittoratos (Esso Resources Canada Ltd.); G.R. Scott (Esso Resources Canada Ltd.); C.I. Beattie (Esso Resources Canada Ltd.) "Cold Lake Cyclic Steam Stimulation:A Multiwell Process" W.T. Peake, SPE Member “Reservoir Simulation of Steam Injection in the Cold Lake Tar Sand “ http://www.imperialoil.com/Canada-English/Files/Cold_Lake_Expansion_Project_Volume1.pdf http://www.imperialoil.com/CanadaEnglish/Files/Cold_Lake_Expansion_Project_Volume1.pdf

Fight On!!!