System for extracting gas from tectonically-deformed coal seam in-situ by depressurizing horizontal well cavity
US10934817B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Oct 18, 2018 |
| Grant date | Mar 2, 2021 |
| Priority date | — |
| Expiry date | Oct 18, 2038 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21F17/18
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A system for extracting gas from a tectonically-deformed coal seam in-situ by depressurizing a horizontal well cavity is provided. A horizontal well is constructed by a horizontal well drilling and reaming subsystem and adjoins a vertical well to form a U-shaped well, and a horizontal section of the horizontal well is reamed to enlarge hole diameter. A horizontal well hole-collapse cavity-construction depressurization excitation subsystem performs pressure-pulse excitation and stress release on the horizontal well of tectonically-deformed coal bed methane, and hydraulically displaces a coal-liquid-gas mixture such that the mixture is conveyed towards a vertical well section along a depressurizing space. A product lifting subsystem further pulverizes the coal and lifts the mixture towards a wellhead of a vertical well. A gas-liquid-solid separation subsystem separates the coal, liquid and gas. A monitoring and control subsystem detects and controls the operation conditions and the execution processes of technical equipment in real time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.