Gravity assisted solvent flooding process
AssigneeMobil Oil Corporation
InventorMaynard L. Anderson
Life of this patent
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Abstract
This invention relates to a method where the soak time, required for solvent and crude oil mixing in the gravity assisted solvent flooding process, is significantly reduced. This is accomplished by inducing vertical flow of solvent into the heavy crude oil part of the reservoir through the use of intermediate wells drilled between injection and production wells and completed in the top of the oil reservoir. Steam or gas may be used prior to the introduction of the solvent to reduce the resistance to subsequent solvent flow.
Claims14
A method for recovering viscous petroleum from subterranean petroleum containing formations penetrated by at least one injection well and by at least one production well, both wells being in fluid communication with the petroleum containing formation comprising the steps of:
- a. drilling and completing at least to the top of the petroleum containing formation at least one intermediate well between the injection and production wells, where said intermediate well has fluid communication with the petroleum containing formation;
- b. while the intermediate wells are colsed in, injecting via said injection well and into the lower part of the petroleumcontaining formation a hydrocarbon solvent where said solvent has a specific gravity less than that of the formation petroleum;
- c. after the solvent is in place at the bottom of the petroleum containing formation, applying pressure to the injection wells or production wells or both followed by opening the intermediate wells thus enhancing the flow of the solvent from the bottom of the formation to the top;
- and
- d. shutting the intermediate wells after desired mixing of petroleum and solvent is achieved, and producing the petroleum and solvent from the production wells.
Dependencies are inferred from the claim text.