Downhole coal seam pulse detonation wave directional fracturing permeability-increasing method
US9951597B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 28, 2015 |
| Grant date | Apr 24, 2018 |
| Priority date | — |
| Expiry date | Dec 28, 2035 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21F7/00
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A method for permeability improvement for a downhole coal seam by directional fracturing with pulsed detonation waves, which is applicable to gas control in coal seam areas with high gas concentration and low air permeability. The permeability improvement method is as follows: first, drilling a pulsed detonation borehole and pulsed detonation guide boreholes from a coal roadway to a coal seam respectively; then, pushing a positive electrode connected to a positive output side of an explosion-proof high-voltage electrical pulse generator to the bottom of the pulsed detonation borehole and pushing a negative electrode connected to a negative output side of the explosion-proof high-voltage electrical pulse generator to the bottom of the pulsed detonation guide borehole; connecting the pulsed detonation borehole and the pulsed detonation guide boreholes to an extraction pipeline for gas extraction, after electrical pulsed detonation fracturing for the coal seam is carried out. The method disclosed in the present invention utilizes the high instantaneous energy provided by electrical pulsed detonation waves to fracture a coal mass, so as to form a fissure network in the coal mass betwee…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.