Wellbore drilling using dual drill string
US9702210B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 6, 2014 |
| Grant date | Jul 11, 2017 |
| Priority date | — |
| Expiry date | May 6, 2034 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B33/085
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A method and apparatus are disclosed for drilling a wellbore using a concentric dual drill string. Multiple individually selectively isolable crossover ports intervaled may be provided along the length of the drill string thereby facilitating pumping a well control fluid within a wellbore annulus without the need to run-in or trip-out the drill string. Multiple one way check valves may be included at various points within an inner pipe of the dual drill string to minimize settling of particulate matter during long periods of non-circulation. In an offshore arrangement, the drill string may be used without a marine riser. A rotating control device is provided, and a hydraulic power unit is located at the seafloor for controlling and lubricating the rotating control device. A pump may be located at the seafloor for managing wellbore annulus pressure via the rotating control device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.