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US 4,009,578 AGranted
Method for preventing fluid migration in coal seams
AssigneeContinental Oil Company
InventorDai S. Choi
Life of this patent
Estimating the term…
Abstract
A method for preventing fluid migration in coal seams by forming a substantially fluid impermeable zone across the fluid migration path by positioning at least one borehole in the coal seams in a direction generally parallel to the direction of fluid migration; injecting anhydrous hydrogen chloride or ammonia into the coal seams through the boreholes; and thereafter plugging the boreholes to prevent retrograde flow of the hydrogen chloride or ammonia.
Claims10
A method for preventing fluid migration in a coal seam, said method consisting essentially of forming a substantially fluid impermeable zone across the fluid migration path by
- a. positioning at least one borehole in said coal seam in a direction generally parallel to the direction of fluid migration;
- b. injecting a substantially anhydrous material selected from the group consisting of hydrogen chloride and ammonia at a pressure sufficient to force said material into the coal seam surrounding said borehole, but less than the fracturing pressure of said coal seam, in an amount equal to from about 0.01 to about 5.0 weight percent based on the weight of the coal contacted by said material;
- and
- c. plugging said borehole to prevent retrograde flow of said materials.
1 more element
Dependencies are inferred from the claim text.