Vastar Resources, Inc.

Stephen V Bross

Walter C Riese

Vu P Dinh

A method for increasing the production of methane from a subterranean carbonaceous formation by chemically stimulating the formation of additional free surface area or cleats in the organic constituents of the formation and by causing inorganically adsorbed methane to be released from contained clay-minerals to increase the rate of methane desorption from the formation by injecting an aqueous oxidizing solution containing at least one oxidant into the formation, and thereafter producing methane from the formation at an increased rate. Suitable oxidants include peroxide, ozone, oxygen, chlorine dioxide, sodium hypochloride, water soluble salts of hypochlorous acid, perchlorate, chlorate, persulfate, perborate, percarbonate, permanganate, nitrate and combinations thereof.

Chemically induced stimulation of subterranean carbonaceous formations

A method for increasing the production of methane from a subterranean coal formation by chemically stimulating the formation of cleats in the formation to increase the rate of methane production from the formation by injecting an aqueous oxidant solution into the formation to stimulate the formation of cleats in the formation; and thereafter producing methane from the formation at an increased rate. Suitable oxidants include chlorine dioxide, metallic salts of perchlorate, chlorate, persulfate, perborate, percarbonate, permanganate, nitrate and combinations thereof.

Chemically induced stimulation of cleat formation in a subterranean coal

A method for increasing the methane recovery from a subterranean carbonaceous formation by chemically stimulating the formation of cleats and increasing the surface area in the carbonaceous formation by injecting a gaseous oxidant into the carbonaceous formation to stimulate the formation of cleats in and increase the surface area of carbonaceous material in the carbonaceous formation; and thereafter producing methane from the carbonaceous formation at an increased rate. The gaseous oxidant may be ozone, oxygen or combinations thereof.

A method for increasing the permeability to methane of a subterranean coal formation by chemically stimulating the coal formation by injecting a gaseous oxidant into the coal formation and thereafter producing methane from the coal formation at an increased rate. The gaseous oxidant is ozone, oxygen or combinations thereof. The completion of wells penetrating a subterranean coal formation is facilitated by injecting a gaseous oxidant into the coal formation surrounding the well prior to forming a cavity in the coal formation around the well.

Chemically induced permeability enhancement of subterranean coal

A method for increasing the production of methane from a subterranean coal formation penetrated by an injection well and a production well by producing methane from the coal formation via the production well; passing a portion of the methane to a synthesis gas generation zone wherein at least a portion of the methane is reacted with an oxygen-containing gas to produce a mixture of carbon monoxide and hydrogen; passing a major portion of the mixture to a hydrocarbon synthesis zone wherein the carbon monoxide and hydrogen are reacted to produce heavier hydrocarbons and a tail gas comprising nitrogen and carbon dioxide; separating a major portion of the tail gas from the hydrocarbons and recovering the hydrocarbons as a product stream; injecting at least a portion of the tail gas into the coal formation through the injection well. The methane may be obtained from a single well or a plurality of wells operated to produce the methane by a huff and puff process.

Method for increasing methane recovery from a subterranean coal

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.

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Sugar Land, TX, United States of America

Stephen V Bross