A new and proprietary in-situ recovery process for bitumen enhanced oil recovery is described herein (International PCT Patent Application No. PCT/CA2012/000652). SAGDOX (Steam Assisted Gravity Drainage (SAGD) with the addition of OXygen injection) is a reservoir recovery process that uses steam and oxygen injection to produce in-situ energy for bitumen enhanced oil recovery. The primary production process is gravity drainage to a horizontal production well. The mixture is synergistic in that oxygen contributes to heat in the reservoir by oxidizing residual bitumen left behind in the steam-swept zone of the reservoir and steam helps stabilize and pre-heat combustion. SAGDOX may be considered as a hybrid process combining and enhancing the benefits of SAGD and in-situ combustion (ISC), with a method to optimize steam/oxygen ratios as the process matures.
The SAGDOX process can be applied to bitumen reservoirs that are currently being developed with SAGD and to non- SAGD reservoirs, such as thin pay bitumen, lean zone bitumen, and deep bitumen zones. SAGDOX is currently in the early stage of development with laboratory experimentation and physical model testing underway. There has been no field testing or piloting of the SAGDOX process to date.
SAGDOX has the potential to significantly reduce steam-oil ratios and operating costs. Oxygen has an order-of-magnitude greater energy density than steam on an equivalent volume basis.
This paper will present and discuss the results of the Long Lake bitumen characterization, ramped temperature oxidation, and combustion tube tests, as well as physical model experiments comparing SAGDOX to SAGD. Successful results from the laboratory program will lead to a field trial of this new in-situ bitumen recovery process.
SAGDOX shows the potential to be a revolutionary process for the development of the Athabasca bitumen reservoirs in Alberta.