Process for recovering methane gas from subterranean coalseams
US4651836A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 1, 1986 |
| Grant date | Mar 24, 1987 |
| Priority date | — |
| Expiry date | Apr 1, 2006 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21F7/00
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A process provides for the recovering of methane gas from subterranean coalseams having sloughing, or caving, characteristics. A borehole is drilled in a generally horizontal direction into a subterranean coalseam and as the drilling progresses, a flushable borehole cake is formed on and in the walls of the horizontal borehole. The borehole cake prevents contemporaneously sloughing, or caving, of the boreholes during the drilling operation. A perforated liner may be inserted into the horizontal borehole and the borehole cake is then flushed out in order to allow methane gas present in the coalseam to enter the liner from which it is collected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.