04385662 is referenced by 18 patents and cites 7 patents.

Oil may be recovered from viscous oil-containing formations including tar sand deposits by providing at least one injection well and at least one spaced-apart production well which extend downwardly from the surfaces and which extend to, and generally horizontally through, the bottom of the oil-containing formation with fluid communication of the horizontally extending portions of each well with the oil-containing formation. Solvent is injected into the injection well and fluids including oil are recovered from the production well until the fluid recovered contains an unfavorable amount of solvent, preferably at least 90 percent. After injection of the solvent is terminated, both the injection well and the production well are shut-in and the formation is allowed to undergo a soak period for a predetermined time, preferably for a time of between 2 to 20 days per foot of formation thickness. After the soak period, solvent is injected into the production well and fluids including oil are recovered from the injection well until the fluid recovered contains an unfavorable amount of solvent, preferably at least 90 percent. After injection of the solvent into the production well is terminated, both wells are shut-in and the formation is allowed to undergo a second soak period for a predetermined time, preferably for 2 to 20 days per foot of formation thickness. Thereafter, a driving fluid is injected into the formation via the injection well to effect a fluid drive of the oil through the formation and oil is produced from the production well until the oil being produced contains an unfavorable amount of driving fluid, preferably at least 90 percent.

Title
Method of cyclic solvent flooding to recover viscous oils
Application Number
6/308754
Publication Number
4385662
Application Date
October 5, 1981
Publication Date
May 31, 1983
Inventor
John L Fitch
Dallas
TX, US
Lynn D Mullins
DeSoto
TX, US
Agent
Lawrence O Miller
James F Powers Jr
Charles A Huggett
Assignee
Mobil Oil Corporation
NY, US
IPC
E21B 43/22
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