Interlake Facies & Reservoir, Bryant and Adjacent areas, Southeast Saskatchewan

Until late 2007,the Silurian Interlake Formation (Llandoverian-Wenlockian) in southeastem Saskatchewan had not been regarded as a significant exploration target, despite a long history of production from equivalent reservoirs in the central portion of the Williston Basin, largely from structural traps along the Nesson Anticline in North Dakota. In November 2001, Nexen Canada Ltd. discovered significant quantities of oil in dolomitic carbonates (Taylorton sub-unit) of the Interlake at Bryant (7-4-5-7W2). Subsequent drilling has proven the commercial viability of this discovery. In North Dakota, the Interlake has produced9.22 million m3 of oil (58 MMBO) representing some 4 percent of that state's total production. Prior to the Bryant Interlake discovery, only a handful of Interlake oil shows had ever been recorded in Saskatchewan. The first was in the Mobil N. Redvers 14-19-8-32W1M drilled in 1957. Five drillstem tests were run in the Interlake, with the most successful recovering 30.5 m of oil cut mud and27.5 m of mud cut oil from the uppermost part of the Interlake (Taylorton Mbr.). A completion was attempted, but the well was eventually abandoned without production. Other wells with Interlake oil shows on drillstem test include, Tidewater Wapella Crown l2-34-14-lW2M (16.8 m of oil and water cut drilling mud), lmperial Douglaston 12-6-53W2M (228.6 m of salt water cut oil) and most recently (1996) Berkley et al Midale 1029-6-llW2M (400 m of oil and water cut mud). A few other wells have recovered gas cut water from the Interlake, including Mobile CDR Flat Lake 5-30-l-15W2M, Pan Am OUHL A-l Caron I0-10-17-29W2M, Shell Big Muddy Lake l5-12-3-21W2M and Socony Sohio Briercrest l4-ll-I4-24W2M. Oil staining has also been identified in a number of cores and cuttings most notably Mark Minton 5-17-3-2lW2M where the presence of spotty oil stain and yellow-white fluorescence corresponds to a small gas kick at the top of the Interlake on the striplog. The discovery well for the Bryant Interlake was the 7-4-5-7W2M well spudded on October 25,200I as an Ordovician Red River test. Three zones were tested on penetration in this well including the Frobisher, Ratner Mbr (Winnipegosis Fm.) and the Interlake Fm. All of the tests were successful and oil to surface was recorded in both the Ratner Mbr..and Interlake Formations, suggesting a multizone discovery of some magnitude had been made. No water was recovered from either the Ratner or Interlake test intervals. The well subsequently TD'd in the Winnipeg Shale and addition tests were run in the deeper part of the well after logging. After several mis-runs in the Red River