Exploration for reef reservoirs in the "Deep Basin" of Alberta during the mid-1960s resulted in the discovery at Strachan and Ricinus West of 1.9 Tcf of sales gas, 50 million bbl of condensate, and 24.5 million long tons of sulfur in two reefs of Late Devonian age. The reefs were discovered in 1967 and 1969, respectively, by adapting the seismic common-depth point (CDP) techniques of data acquisition and processing that were being developed (particularly in the Rainbow area, in the shallower part of the Western Canada sedimentary basin).

The key well for these discoveries was the Gulf-Strachan well in Isd. 12-31-37-9 W5M, which was drilled in 1955. This well encountered a partial buildup of an Upper Devonian reef which yielded some gas and salt water at a depth of 13,900 ft (4,237 m). CDP seismic data were acquired and, after considerable experimentation in processing with orientation to the appropriate geologic model, showed that the key well was on the flank of what is now called the Strachan reef. In 1968, Banff and Aquitaine drilled a full reef buildup of 900 ft (274 m) in Isd. 10-31-37-9 W5M with a pay section of 536 ft (165 m). A separate pool, the Ricinus West reef, was discovered in 1969 by Banff and Aquitaine in Isd. 6-25-36-10 W5M. The well showed a reef buildup of 800 ft (245 m) and a maximum pay of 634 ft 193 m). Remaining reserves of marketable natural gas at Strachan and Ricinus West, after 6 years of production, are about 1 Tcf.