Method of performing combined drilling, flushing, and cutting operations on coal seam having high gas content and prone to bursts to relieve pressure and increase permeability
US10280686B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 31, 2016 |
| Grant date | May 7, 2019 |
| Priority date | — |
| Expiry date | Apr 16, 2036 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21F7/00
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A method of performing coupled drilling, flushing, and slotting operations on a coal seam, which has a high gas content and prone to bursts, is described herein. The method is aimed to relieve pressure and increase permeability when drilling a through-seam borehole to pre-drain gas belts in a coal mine roadway. The pressure relief and permeation method of the present invention adjusts the water jet water inlet pressure in different stages according to the different positions of the drilling construction, and controls the water during drilling. At drilling stage, the jets are respectively subjected to low-pressure water flow drilling and medium-pressure water flow flushing. When withdraw drilling, the high-pressure water flow slotting is carried out. By doing so, the pressure is relieved in a low, medium, high stepwise manner.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.