Suncor Energy Inc. has received regulatory approval to test downhole electrical heating in a single well at its MacKay River SAGD project. The company intends to use the system to pre-heat the reservoir prior to steam injection and confirm potential to reduce pad-level steam usage, accelerate production ramp-up and improve peak oil rates.

The company noted that electrical heaters have been piloted in Canadian reservoirs since 2004 including by Royal Dutch Shell plc at its Viking project in December 2004 and at its Grosmont carbonate project in 2012; by Athabasca Oil Corporation at its Leduc carbonate property in 2012; and by Perpetual Energy Inc. at its Panny LEAD pilot in October 2015.

Suncor’s test at MacKay River will use an injector well on its Pad 750, which is located nearby the project’s central processing facility.

The well will be equipped with a 73-millimetre coiled tubing containing instrumentation and three electricity-powered mineral insulated heater cables, Suncor said.

“The MI heater cables will indirectly exchange heat with the reservoir mainly via conduction. A resistive alloy makes up the center of the cable and is run into the horizontal or ‘hot’ section of the well. The resistive alloy is insulated by magnesium oxide and the entire assembly is sheathed in stainless steel. For the cold section of the well, the resistive alloy is transitioned to copper so that minimal heat is generated in the vertical and build sections of the well to maximize the delivery of thermal energy to the reservoir.”

Suncor plans to ramp-up up the heating rate to 600 Watts/m over the first two weeks. The company said that once a significant temperature increase is observed at the producer well, it will evaluate if enough data has been collected to conclude the test. The maximum wellbore temperature during heating will be 300 C.

“Preliminary reservoir numerical studies suggest that it will take at least six months before the producer observes any significant heat from the injector. The downhole heater technology will be evaluated for approximately six to 18 months of continuous hearting.”