Dr. Roger Butler, engineer at Imperial Oil from 1955 to 1982, invented the steam assisted gravity drainage (SAGD) process in the 1970s.
As a specific example of an underlying data weakness, this figure excludes the increasingly important steam-assisted gravity drainage technique (SAGD) method.
The heat from the steam reduces the viscosity of the heavy crude oil or bitumen which allows it to flow down into the lower wellbore.
However, real life reservoirs are invariably heterogeneous therefore it becomes extremely difficult to achieve a uniform sub-cool along the entire horizontal length of a well.
As a consequence many operators, when faced with uneven stunted steam chamber development, allow a small quantity of steam to enter into the producer to keep the bitumen in the entire wellbore hot hence keeping its viscosity low with the added benefit of transferring heat to colder parts of the reservoir along the wellbore.
Another variation sometimes called Partial SAGD is used when operators deliberately circulate steam in the producer following a long shut-in period or as a startup procedure.
Combined with the higher oil recovery rates achieved, this means that SAGD is much more economic than cyclic steam processes where the reservoir is reasonably thick.
He tested the concept with Imperial Oil in 1980, in a pilot at Cold Lake which featured one of the first horizontal wells in the industry, with vertical injectors.
Its first facility was owned and operated by ten industrial participants and received ample government support (Deutsch and McLennan 2005)[2] including from the Alberta Heritage Savings Trust Fund.
The Foster Creek plant in Alberta Canada, built in 1996 and operated by Cenovus Energy, was the first commercial Steam-assisted gravity drainage (SAGD) project and by 2010 Foster Creek "became the largest commercial SAGD project in Alberta to reach royalty payout status. "
As a specific example of an underlying data weakness, this figure excludes the increasingly important steam-assisted gravity drainage technique (SAGD) method.
However, by 2011 there was inadequate data on the amount of water used in the increasingly important steam-assisted gravity drainage technique (SAGD) method.
Though to offset the drastic reduction in fresh water use, industry has begun to significantly increase the volume of saline groundwater involved.
[25] Relying upon gravity drainage, SAGD also requires comparatively thick and homogeneous reservoirs, and so is not suitable for all heavy-oil production areas.
By 2009 the two commercially applied primal thermal recovery processes, steam-assisted gravity drainage (SAGD) and cyclic steam stimulation (CSS), were used in oil sands production in the Clearwater and Lower Grand Rapids Formations in the Cold Lake Area in Alberta.
Steam is re-injected to begin a new cycle when oil production rates fall below a critical threshold due to the cooling of the reservoir.
[4] "Roughly 35 per cent of all in situ production in the Alberta oil sands uses a technique called high pressure cyclic steam stimulation (HPCSS), which cycles between two phases: first, steam is injected into an underground oil sands deposit to fracture and heat the formation to soften the bitumen just like CSS does, excepting at even higher pressures; then, the cycle switches to production where the resulting hot mixture of bitumen and steam (called a "bitumen emulsion") is pumped up to the surface through the same well, again just like CSS, until the resulting pressure drop slows production to an uneconomical stage.
"[28] In the Clearwater Formation near Cold Lake, Alberta the high pressure cyclic steam stimulation (HPCSS) is used.
[4] Canadian Natural Resources Limited's (CNRL) Primrose and Wolf Lake in situ oil sands project near Cold Lake, Alberta in the Clearwater Formation, operated by CNRL subsidiary Horizon Oil Sands, use the high pressure cyclic steam stimulation (HPCSS).
[4] Alternative enhanced oil recovery mechanisms include VAPEX (Vapor Assisted Petroleum Extraction), Electro-Thermal Dynamic Stripping Process (ET-DSP), and ISC (for In Situ Combustion).
VAPEX, a "gravity-drainage process that uses vapourized solvents rather than steam to displace or produce heavy oil and reduce its viscosity, was also invented by Butler.
[29] ET-DSP is a patented process that uses electricity to heat oil sands deposits to mobilize bitumen allowing production using simple vertical wells.
The THAI facility in Saskatchewan was purchased in 2017 by Proton Technologies Canada Inc., who has demonstrated separation of pure hydrogen at this site.