This paper will review progress made to date on a field pilot program to develop steam stimulation as a commercially viable process for the Athabasca Oil Sands deposit in Alberta, Canada.
The McMurray formation of the Athabasca Oil Sands Deposit contains extra heavy oil with a viscosity of over 1 000 000 mPa.s at reservoir conditions. The formation is a shallow, uncemented sand. Unlike the Clearwater formation in the Cold Lake Deposit, there are no commercial in-situ projects in the Athabasca Deposit. A number of pilot projects were carried out in the 1960's and 1970's, but most were considered to be unsuccessful.
Petro-Canada, as operator for the PCEJ Group, has been operating single well steam stimulation tests in the McMurray Formation near Fort McMurray since 1978. During this period, operating problems related to sand production, fluid lifting and produced fluid handling have been overcome, and considerable progress has been made towards optimizing operating parameters such as steam slug size. The performance of the single well tests were sufficiently encouraging for the group to begin design and construction of a thirteen well pilot in 1989. Steam injection in the pilot commenced in May of 1990.
The results of the three single well tests will be summarized and the pilot design, test program, and initial performance reviewed.
The Hangingstone Pilot Project utilizes an optimized cyclic steam stimulation (CSS) technique to extract bitumen from the Athabasca oilsands which is considered to be one of the world's largest hydrocarbon deposits. The bitumen viscosity at reservoir condition is over 1 000 000 mPa.s and will not flow naturally. The production zone is the McMurray formation located at a depth of 270 m.
Petro-Canada has been operating the Hangingstone Project in the McMurray Formation near Fort McMurray since 1985. The Project is a joint venture of Petro-Canada, Canadian Occidental Petroleum Ltd. Esso Resources Canada Limited, and Japan Canada Oil Sands Ltd., collectively known as the PCEJ Group. The Alberta Oil Sands Technology and Research Authority (AOSTRA) is planning to participate in further technological development. The project initially consisted of three single well, steam stimulation tests. The results of the single well tests were sufficiently encouraging, that the group began the design and construction of a thirteen well pilot in 1989.
Figure 1 shows the location of the oilsands deposits of Alberta. The PCEJ Hangingstone Project is located 50 km southwest of the city of Fort McMurray on one of the 34 leases held by the PCEJ group. Figure 2 provides more details of the local area.
The lone of interest in the PCEJ Project is the Lower McMurray sand. The McMurray sand is Cretaceous in age and consists of a sequence of unconsolidated sands and shales. The McMurray overlies an unconformity surface developed on middle Devonian Beaverhill Lake carbonates, and is overlain by the Wabiskaw member of the Clearwater Formation.
The depositional environment of the McMurray is predominantly fluvial but changes to deltaic and then to marine as the sand progresses upward The reservoir sands were deposited in a channel network and as a result, have poor lateral continuity.
