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OSLI is issuing an incentive challenge to find game-changing steam generation technology that could reduce the cost and environmental footprint of the most frequently used in situ oil sands recovery method — Steam Assisted Gravity Drainage (SAGD).

“We’re looking for new technology that would deliver reliable steam production using lower quality water,” explains Craig Pichach, an engineer working with OSLI’s Technology Breakthrough Working Group.

He explains SAGD technology requires steam, which is injected into the ground to heat molasses-like bitumen until it flows and can be pumped to the surface. The steam is produced using brackish water — hard, salt water found deep underground that naturally contains impurities such as silica.

“The good news is brackish water is not good for anything else — no one wants it. But the down side is that can be expensive to remove enough impurities that it can  be used in the SAGD process.”

Impurities must be removed from the brackish water before it is fed into Once Thru Steam Generators (OTSGs), Heat Recovery Steam Generators (HRSGs) or conventional drum boilers used at SAGD facilities to produce steam. Once removed, the impurities are returned to the underground caverns the brackish water came from.

The steam is injected into the bitumen reservoir and most of it is recovered, separated from the oil, and cooled until it becomes water once again. Called process water, it is recycled and used to produce more steam for the SAGD operation.

“But we lose 3 to 10 per cent of the steam to the reservoir and boiler blowdown so we constantly have to add ‘make-up water’ to the process water. In this case, brackish water is added to the process water, which means it has to be treated again so it doesn’t foul the steam generators.”

Most SAGD operations only use brackish water for creating the large volumes of steam required to heat the reservoir although occasionally fresh water is used as make-up water.

A typical SAGD operation requires 96,000 barrels per day (bpd) of cold-water equivalent (CWE) steam to produce 30,000 barrels bpd of oil, which translates into a steam-oil ratio (SOR) of 3.2.  The lower the SOR, the more economic the operation.

Pichach, an oil sands surface technical engineer with Nexen, says reducing the number of steps and treatment facilities required for treating brackish water would also reduce use of natural gas and associated carbon dioxide emissions from SAGD operations. At the same time, concentrating water treatment in fewer vessels would mean a reduced footprint for SAGD, which already has a minimal land impact.

He points out that reducing costs and environmental impacts of SAGD is important since roughly 80 per cent of Alberta’s oil sands deposits lie more than 75 metres beneath the earth’s surface and can only be recovered using in situ methods. And SAGD is currently the most commonly used method used to recover in situ oil sands. “We’re trying to improve the economics of SAGD since there is a lot of bitumen that can be accessed using this technology.”

This is the second time OSLI has used an incentive challenge or prize, commonly known as open sourcing, to find a solution to a technical issue. Incentive challenges involve offering financial support to individuals from all different fields to prove credible solutions to issues.

“There is no boiler technology that delivers reliable steam production with low quality process water. Since this project is really challenging some assumptions as to what’s possible, we thought it would be best to go outside the industry to see what others have developed that might be applicable here.”

In the first OSLI incentive challenge, 16 responses were received from individuals/companies who felt they could overcome the challenges of accurately counting and identifying mammals in the boreal forest of Northern Alberta.

Like the first challenge, this one is managed by NineSigma, one of the most experienced and advanced providers in this emerging field. NineSigma will post details of the OSLI challenge online and distribute the details to highly connected groups in the academic and research world. These groups will pass the information along to others who might have an interest in this area. The challenge will remain open for four weeks before the proposals will be evaluated by OSLI.

If proposals meet OSLI’s requirements, then funding of up to $50,000 is available for Phase 1, which involves proving the concept. If successful, Phase 2 will involve fabrication of a prototype. Depending on that success, it will be followed by Phase 3, which would include a pilot operation, with Phase 4 resulting in commercialization.

Comments

• Seston
  August 4, 2011, 6:18 pm
  Unbelievable how well-written and inofmravtie this was.

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