Steam generation is a central part of the bitumen production process at steam assisted gravity drainage (SAGD) facilities. Most SAGD facilities have Once Through Steam Generators (OTSG) which burn natural gas to boil water, producing steam that is injected into the ground to soften bitumen. The bitumen is then extracted through a producing well and the majority of the water is treated and recycled. The Gas-Turbine OTSG (GT-OTSG) works on the same premise, except the gas turbine produces electricity that can be used to power the facility. Waste heat in the turbine exhaust is utilized in the OTSG to produce steam.
The GT-OTSG’s gas turbine is the key to producing electricity at the same time it produces steam for a SAGD facility. This technology is being tested in a pilot scale demonstration at Surmont, a joint venture between ConocoPhillips Canada (CPC) and Total E&P Canada. The enabling technology of the GT-OTSG process is a burner developed by CPC. It burns the natural gas and the hot turbine exhaust, allowing the unit to operate more efficiently than competing co-generation configurations. When hot exhaust from the turbine is delivered to the burner, it improves the efficiency of the OTSG, further reducing the facility’s overall emissions.
One of the unique benefits of this GT-OTSG technology is its operational flexibility. Parts of the GT-OTSG unit can be shut down individually, with minimal disruption to operations. Additionally, while the highly-integrated nature of the operation is what maximizes efficiency, the burner can also be fired on a stream of fresh air, which allows for maximum operating flexibility.
Natural gas powers a turbine which produces electricity that can be used to power the facility, reducing its reliance on the Alberta power grid. Since the Alberta power grid is primarily supported by carbon-intensive coal-fired power plants, this results in a per-barrel net reduction in the carbon intensity of bitumen products by approximately 17 per cent.
GT-OTSG technology was contributed to COSIA companies by ConocoPhillips Canada. Both the burner study and full-scale pilot are being undertaken at the Surmont oil sands facility, a joint venture between ConocoPhillips Canada and Total E&P Canada.
Contributing a technology to COSIA means that, as part of COSIA, CPC has shared the technology with other member companies. In return, the contributed technology process provides equitable sharing of different technologies and innovations among COSIA members. In this way, COSIA’s structure allows for great leaps in available environmental technologies and innovations across the industry.