Numerical Simulation Study of a Well In the JACOS Hangingstone Steam Pilot Project Near Fort McMurray
Authors: Ito Y. , Hirata T. 
Published: March 2010

This paper presents a numerical simulation study of a well in a pilot project which has 13 steam stimulation wells in an oil sand reservoir near Fort McMurray. Steam injection commenced May 1, 1990 as a joint project by Petro-Canada, Imperial Oil Resources, Canadian Occidental Petroleum Ltd. and Japan Canada Oil Sands (JACOS).

A special emphasis has been made on the energy distribution around the subject well. Many thermocouples have been installed in the wellbore outside of the casing and three temperature observation wells have been drilled at 12 m distances from the well.

A numerical history match was conducted when the well completed its seventh cycle of production. The bottom-hole temperature, bottom-hole pressure, fluid production of each phase and temperature profile at the observation wells were used as history match parameters.

The simulation results indicate that a failure zone was mainly created in the top of the upper McMurray formation which overlies the target oil zone during the first two cycles. The location of this failure zone gradually shifted downwards as the cycles progressed. The failure zone developed mainly in the lower part of the Upper McMurray formation during the third and fourth cycles, and in the top of the Lower McMurray formation, the target oil zone, during the fifth and sixth cycles. This downward change in the location of the failure zone caused a gradual improvement in oil production by cycle.

To achieve a history match of all field observations, a good representation of the failure zone is an essential requirement. The Sand Deformation module interfaced with CMG's STARS model was used in this study. It was discovered that all of the field observations could not be matched simultaneously without this special version of the model.

Introduction

The Hangingstone Steam Pilot utilizes a cyclic steam stimulation (CSS) process to extract bitumen from the Athabasca oil sands. The bitumen viscosity at reservoir condition is over 1,000,000 mPa.s and will not flow naturally.

Petro-Canada initially operated the CSS Pilot project near Fort McMurray from 1985 to April 1992 as a joint venture of Petro- Canada, Canadian Occidental Petroleum Ltd., Imperial Oil Resources, and Japan Canada Oil Sands Ltd. (JACOS), known as the PCEJ Group. Then JACOS subsequently took over the project.

The project initially consisted of three single well steam stimulation tests. One of the interesting results of the single well tests was that oil production progressively improved with time. The mechanism of this behaviour was not clearly understood at that time. A thirteen multiwell pilot test commenced on May 1990 based on the results of the single well tests. A unique feature of the multiwell project is that three temperature observation wells were drilled at a distance of 12 m from well C2 in an equilateral triangle around the well. The temperature response in these wells has helped monitor heat and fluid movement in the reservoir. In addition to this, 20 thermocouples have been installed in well C2 outside of the casing at 1 – 2 m intervals within the target formation.