Partners in a pilot development of the Late Devonian Grosmont formation in Alberta report progress toward commercial production of bitumen, which would be the first for the expansive carbonate.
Laricina Energy Ltd., the operator with 60% interest of the Saleski project in the Athabasca region, recently amended its application for first-phase development to focus on the Grosmont C zone with development via cyclic steam-assisted gravity drainage (OGJ Online, Nov. 13, 2012).
In separate presentations recently, Laricina and the other partner, Osum Oil Sands Corp., reported new details of results of the pilot project, from which total bitumen production has been as high as 1,800 b/d. Both companies are based in Calgary.
The Alberta Energy Resources Conservation Board estimates the Grosmont, from which commercial production hasn’t yet been established, holds 406 billion bbl of bitumen in place under 1.766 million hectares.
In its presentation, Osum said the first Saleski pilot well pair, 1D, drilled to 800 m in 2010 and stimulated after initial start-up, has produced at rates as high as 700 b/d with average producing day cycle rates of about 270 b/d.
The second well pair, 1C, also drilled in 2010, went on production in the second quarter of 2011 and has produced more than 800 b/d with average producing day rates exceeding 445 b/d in the first and second cycles. The partners tested steam-solvent coinjection in the fourth cycle, which is currently on production.
The third well pair, 2C, was drilled in the first quarter last year and stimulated before start-up. The 2C well pair has achieved production as high as 1,200 b/d, with average producing day rates in the first and second cycles of 470-660 b/d.
In the second cycle, the 2C well pair had a steam-oil ratio (SOR) below 3.5, which is in the commercial range for SAGD projects. The well pair is back on steam injection.
Laricina said 2C work included successful implementation of underbalanced drilling, a linerless horizontal section, and well stimulations.
It said the pilot has shown the Grosmont can produce at commercial rates, describing productivity per meter of well length as “best in class.” It also said oil has been mobilized quickly, with seismic and observation well data demonstrating heat remains near the well bore with limited fracture thermal leak-off.
Laricina said the pilot enhanced understanding of the communication between wells and across the C-D marl. And it said the steam-production cycling process “provides understanding on optimized well start-up.”
Osum said the choice between SAGD and cyclic SAGD as the core process at Saleski “is not expected to materially impact project returns.” Savings in capital and operating costs resulting from the use of cyclic SAGD, which uses one instead of two horizontal wells, is “largely balanced” by the potential effects of a higher SOR, it said.
Osum indicated the first phase of commercial development might be expanded to target production of 12,500 b/d from 10,700 b/d.
The companies estimate cost of commercial development at $600 million.
In addition to its interest in the Saleski joint venture with Laricina, Osum holds 100% interests in the nearby Sepiko Kesik (Saleski East), Saleski West, and Liege areas.
It expects to submit applications early this year for development of an initial 30,000 b/d of bitumen from the Sepiko Kesik project, which is 1 km east of the Saleski pilot. It esimates the Sepiko Kesik resource can support production of as much as 90,000 b/d of bitumen.