The Mississippian Midale in southeast Saskatchewan has produced substantial hydrocarbons since the 1950’s. Since 2012, several companies have utilized multi-stage hydraulic fracturing in lower permeability Midale reservoirs with impressive results. Low production decline rates and existing facilities lead to strong economics, and the play is further boosted by large original oil-in-place (OOIP) volumes as it covers a large geographic area. The reservoirs are dolostones in the upper “Marly” unit and limestone in the lower “Vuggy” unit. The overlying Midale Evaporite, an extensive evaporitic mud flat/playa lake deposit within the basal Ratcliffe Beds, provides a seal for hydrocarbon accumulation.
In the Steelman and Macoun areas, operators have been drilling open hole horizontal wells in some areas, as well as multi-stage hydraulically fracturing wells where deliverability is reduced.