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US 4,283,089 AGranted
Pretreatment for fracturing coal seams
AssigneeConoco Inc.
InventorsRaymond L. Mazza, H. Douglas Dahl, Ronald W. Umphrey
Life of this patent
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Abstract
A pretreatment for use in fracturing coal seams to increase gas permeability of the seams. The pretreatment involves injecting a material capable of swelling coal into a coal seam prior to fracturing the coal seam. The pretreatment material swells the coal and closes the natural cleats therein, enhancing the effectiveness of the subsequent fracturing step.
Claims6
A method of pretreating and hyraulically fracturing a coal seam comprising:
- (a) injecting a pretreatment material capable of swelling coal into a coal seam to be fractured, said material being injected at less than fracturing pressure;
- (b) allowing the coal seam to swell as a result of contact with said material, thereby reducing the permeability of cleats in the pretreated portion of said coal seam;
- and
- (c) subsequently subjecting said pretreated portion of said coal seam to hydraulic fracturing.
1 more element
Dependencies are inferred from the claim text.