Method for profile control of enhanced oil recovery
AssigneeMobil Oil Corporation
InventorPaul Shu
Life of this patent
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Abstract
A process for profile control in a high permeability zone of a formation. A water flooding or carbon dioxide stimulation enhanced oil recovery (EOR) process is conducted in an an oil-containing formation having a high permeability zone. After breakthrough occurs, the EOR process is ceased. The high permeability zone is heated to a temperature of 300.degree. F. or higher by steam injection. Subsequently, steam injection is ceased and a temperature activated mixture is injected into the high permeability zone where it forms a solid gel. Thereafter, an EOR process can be used to remove hydrocarbons from a low permeability zone.
Claims10
A method for profile control in ehanced oil-recovery in a high permeability zone of a formation comprising:
- (a) conducting an enhanced oil recovery process in a formation which process removes hydrocarbons from a high permeability zone until breakthrough occurs;
- (b) ceasing use of the enhanced oil recovery process after breakthrough occurs;
- (c) injecting steam into the formation and heating the high permeability zone to a temperature sufficient to cause a temperature activated gellable mixture to form a solid gel;
- (d) terminating steam injection into the formation;
- (e) injecting into said formation a temperature activated gellable mixture which mixture enters said heated high permeability zone;
- and
- (f) activating said mixture by the temperature in the heated zone which temperature is sufficient to cause a solid gel to form and close pores in said heated high permeability zone.
A method for profile control in enhanced oil-recovery in a high permeability zone of a formation comprising:
- (a) conducting an enhanced oil recovery process in a formation which process removes hydrocarbons from a high permeability zone until breakthrough occurs;
- (b) ceasing use of the enhanced oil recovery process after breakthrough occurs;
- (c) injecting steam into the formation and heating the high permeability zone to a temperature sufficient to cause a temperature activated gellable mixture to form a solid gel;
- (d) ceasing injection of steam into the formation;
- (e) injecting a temperature activated gellable aqueous mixture into the formation which mixture comprises water, polyvinyl alcohol, phenol and trioxane in an amount sufficient to form a phenolic resin in situ and cross-link with said alcohol at a temperature greater than about 300.degree. F.
- (f) forming a solid gel in a high permeability zone of said formation having a temperature greater than about 300.degree. F.;
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- (g) initiating a water flooding or a carbon dioxide stimulation enhanced oil recovery process and recovering hydrocarbons from a low permeability zone.
Dependencies are inferred from the claim text.