Disposal of produced formation fines during oil recovery
AssigneeMobil Oil Corporation
InventorAlfred R. Jennings, Jr.
Life of this patent
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Abstract
Recovered formation fines are pumped in slurry form into an injection well during an enhanced oil recovery process e.g. a steam flood. Said injection can be done incrementally in stages in conjunction with said process. Said fines improve the sweep efficiency of the injected medium. This method is also beneficial where steam breakthrough has occurred since the breakthrough path is in a fluid or semi-solid state thereby allowing the fines slurry to be injected.
Claims12
A method for disposing of fines recovered during the production of hydrocarbonaceous fluids from a formation comprising:
- (a) making an aqueous saline slurry from said recovered fines;
- (b) injecting incrementally said slurry into a formation via at least one wellbore at a rate and velocity sufficient to close pores in said formation without fracturing said formation where a slug containing a higher concentration of fines in the slurry follows a slug of lower fines concentration;
- and
- (c) decreasing the injection rate and velocity of said slurry thereby causing said fines to settle and close at least one more permeable zone in said formation.
A method for improving the sweep efficiency of an enhanced oil recovery operation comprising:
- (a) making an aqueous slurry from fines recovered from hydrocarbonaceous fluids produced from a formation;
- (b) directing incrementally said slurry into said formation via at least one wellbore at a rate and pressure below that required to fracture said formation but which is sufficient to cause fines to close at least one previously swept area in said formation where a slug containing a higher concentration of fines in the slurry follows a slug of lower fines concentration;
- and
- (c) decreasing the injection rate and velocity of said slurry thereby causing said fines to settle and close at least one previously swept zone in said formation.
Dependencies are inferred from the claim text.