The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 03, 2003
Filed:
May. 30, 2001
Applicant:
Inventors:
Armin Lovenich, Alpen, DE;
Hans-Joachim Doering, Ratingen, DE;
Assignee:
RAG Aktiengesellschaft, , DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21B 4/700 ;
U.S. Cl.
CPC ...
E21B 4/700 ;
Abstract
A method for the in-situ extraction of gas from coal seams is provided. Flow paths are produced in gas-containing coal by opening up the structure of the coal by introducing into a bore hole that is sunk into the coal at least one gas and/or liquid under pressure over a prolonged period of time at a pressure that is less than the lowest principal stress determined in a respective seam layer from which gas is to be extracted. The introduction into the bore hole is carried out with a cyclically fluctuating pressure. Gas is subsequently extracted via the bore hole.