Husky Energy, a fixture in Canada’s oil and gas industry for 60 yrs with extensive experience in heavy oil production, recently completed construction of its first-ever oil sands project.
In late August, Husky began injecting steam into the bitumen reservoir at its wholly owned Tucker Oil Sands Project near Cold Lake, Alta. The CDN$470 million (US$417 million) facility applies the steam-assisted gravity drainage (SAGD) process, which uses steam to heat bitumen in an underground reservoir so that it can be extracted. First oil was expected in November.
Bitumen is a heavy, thick mixture of crude oil, sand, and clay that has the consistency of tar. Very abundant in Alberta, the resource nevertheless is more expensive to produce than lighter, less viscous crude oils. It is commercially produced from the province’s three oil sands areas (OSAs)—Athabasca, Cold Lake, and Peace River.
There are bitumen reserves at the Athabasca OSA shallow enough to be extracted by open-pit (surface) mining. The entire mixture of crude oil, sand, and clay is dug up and the oil is separated from the mixture at a later stage. The reserves at Cold Lake and Peace River, however, are deeper underground. They must be extracted by in situ techniques, which rely on drilling to carry softened bitumen to the surface. Approximately 80% of Alberta’s bitumen is recoverable only by SAGD and other in situ methods.
In SAGD, two horizontal wells—one above the other—are drilled into a reservoir. Steam continuously is injected into the upper wellbore. Softened bitumen drains into the lower wellbore and is pumped to the surface. Well pairs of parallel horizontal wells—one for steam and one for production—make it possible to recover bitumen continuously from oil sands.
Husky expects to recover nearly 348 MMbbl of bitumen from Tucker’s Clearwater formation over the next 35 yrs. During the next 2 yrs, production will increase gradually to the design rate of 30,000 b/d. Currently, there are 32 well pairs on three well pads. According to Husky, an additional eight pads may be needed throughout the project.
The well pairs at Tucker tie into a centralized treating and water handling facility. The central plant comprises equipment for generating steam; treating oil; and treating, recycling, and disposing of water. Husky plans to recycle more than 90% of the water used for steam generation. The company will separate produced water from the bitumen. For other water needs, the facility will use brackish, non-potable, saline groundwater.
Bitumen produced at the Tucker Oil Sands Project will be treated with a diluent and then transported via existing pipeline infrastructure to Husky’s nearby Upgrader in Lloydminster, Sask., where the diluted bitumen will be upgraded into a synthetic crude oil. After upgrading, it will be transported to refineries in Canada and the US.