Method for offshore dual-drive core drilling with three layers of casings under surge compensation
US11959346B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 17, 2021 |
| Grant date | Apr 16, 2024 |
| Priority date | — |
| Expiry date | Sep 17, 2041 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B21/063
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A method for offshore dual-drive core drilling with three layers of casings under surge compensation is provided. According to the method, a drilling vessel is located at set latitude and longitude coordinates by a dynamic positioning system; drill pipes are stabilized by a seabed template; torques and drilling pressures can be transmitted during drilling of the casings by means of surge compensation of the casings at a wellhead; during drilling for sampling, the surge compensation can compensate to a certain extent for a change in water depth caused by rising or falling tides, or surge, thereby preventing the casings from colliding with equipment and ensuring the safety of wellhead operation; and the drilling of three layers of casings is achieved by means of dual driver heads to effectively protect a wellbore wall, such that high core-drilling rate and good core-drilling quality are achieved during drilling for sampling.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.