Patent ID: 6588503
Filing Date: 2003-07-08
Classification: C09K,E21B,Y02C,Y02P,Y10S

Abstract:
A method of treating a coal formation in situ, comprising:providing heat from one or more heat sources to at least a portion of the formation; allowing the heat to transfer from the one or more heat sources to a selected section of the formation; controlling the heat from the one or more heat sources such that an average temperature within at least a majority of the selected section of the formation is less than about 375Â° C. such that production of a substantial amount of hydrocarbons having carbon numbers greater than 25 is inhibited; controlling a pressure within at least a majority of the selected section of the formation, wherein the controlled pressure is at least 2.0 bar; and producing a mixture from the formation, wherein about 0.1% by weight of the produced mixture to about 15% by weight of the produced mixture are olefins, and wherein an average carbon number of the produced mixture ranges from 1-25.