A drainage unit is the subsurface area allocated to a well completion for drilling and producing in order to maximize oil or gas recovery from a defined or miscellaneous pool. The Government of Saskatchewan's drainage unit/area and setback requirements ensure long-term, equitable, and orderly development of resources while preventing reservoir damage.
In accordance with Section 27 of The Oil and Gas Conservation Act, an application for oil/gas well spacing modifications must be submitted and approved by the Minister of Energy and Resources before licensing a well completion that won't meet the well spacing minimum requirements. Typically, this occurs if a second well is proposed within a drainage unit or if a well is being proposed will not meet the regulated setbacks.
An application for well spacing modification can be made:
- for a single well completion;
- on a large scale, multiple well completions or lands;
- for a pilot application or an application to test a spacing modification;
- to enlarge a drainage unit's size; or
- reduce the regulated setback distances.
Well spacing modifications approved by the Ministry of Energy and Resources are available on the Minister's Order Bulletin Board. All archived Minister's Orders since 2005 can also be found on the bulletin board.