Chemically induced stimulation of coal cleat formation
AssigneeVastar Resources, Inc.
InventorsWalter C. Riese, Stephen V. Bross
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Abstract
A method for increasing the production of methane from a subterranean coal formation by chemically stimulating the formation of cleats in the coal formation in order to facilitate removal of formation water, and increase the rate of methane production from the coal formation is disclosed. The method comprises injecting an aqueous oxidant solution into the coal formations to stimulate the formation of cleats in the coal formation; and thereafter producing methane from the coal formations at an increased rate. The aqueous oxidant solution comprises hypochlorite, metallic salts of hypochlorous acid, hydrogen peroxide, ozone, oxygen and combinations thereof.
Claims19
A method of enhancing the permeability to methane of a water-containing subterranean coal formation having a low permeability to methane penetrated by at least one well, the method consisting essentially of:
- a) injecting an aqueous oxidant solution into the coal formation;
- b) maintaining the aqueous oxidant solution in the coal formation for a selected time to stimulate the formation of cleats in the coal formation;
- c) producing methane from the coal formation at an increased rate.
A method for increasing the permeability to methane of a water-containing subterranean coal formation having a low permeability to methane penetrated by at least one injection well and at least one production well, the method consisting essentially of:
- a) injecting an aqueous oxidant solution into the coal formation through the injection well;
- b) maintaining the aqueous oxidant solution in the coal formation for a selected time to stimulate the formation of cleats in the coal formation;
- and
- c) producing methane from the coal formation through the production well at an increased rate.
A method for increasing the production of methane from a water-containing subterranean coal formation penetrated by at least one injection well and at least one production well, the method comprising:
- a) injecting an aqueous oxidant solution into the coal formation through the injection well until water is recovered from the production well at an increased rate;
- and,
- b) producing methane from the coal formation through the production well at an increased rate.
Dependencies are inferred from the claim text.