Connacher Oil & Gas Ltd. raised bitumen production and lowered steam injection rates in a test of a proprietary method for enhancing steam-assisted gravity drainage with injection of solvent at its Algar oil sands development in Alberta (OGJ Online, Nov. 16, 2012).
The method, which Connacher calls SAGD+, raised the average rate of bitumen production in the Algar 203-1 well pair by 30% in the first 4 months of 2013 over the 4 months prior to the beginning of the test in May 2012. The company reported steam injection was about 10% less between the comparison periods.
Solvent-injection rates over the entire test period have averaged 6% of the steam volume injected. Connacher estimates 92% of the total solvent injected has been recovered.
In the first 5 months of the 203-1 test, the steam-oil ratio reached a level about 33% below pretest levels. The SOR has remained at the lower level despite changes to the steam rate, Connacher said.
In May, the company converted the producer well from gas lift to a submersible pump and is assessing results.
It has been testing SAGD+ at a fourth Algar well pair, 203-4, since July. The 203-1 and 203-4 tests will continue through yearend. Connacher plans to add a SAGD+ trial on at least one well pair at a well pad where steaming is to begin at the end of the third quarter.
Connacher has received regulatory approval for commercial development using SAGD+ and is considering commercial-scale investment in 2014.
The company also said it has trimmed the diluent blend ratio of the diluted bitumen it sells from the Algar and adjacent Pod One development to 20% from 25% and has experienced reductions to as low as 18%. It expects the lower ratio to be sustainable and has decided not to complete a planned diluent recovery unit at Pod One in 2013.
Connacher said its second-quarter production averaged 11,500 b/d, down from 12,406 b/d in the prior quarter because of planned interruptions related to steam-generator upgrades. After the upgrades, field estimates for production in June averaged 12,500 b/d. Production is about evenly divided between Algar, which began production in 2010, and Pod One, which started up in 2007.
Algar and Pod One are in the Great Divide area 80 km southwest of Fort McMurray.