Monobore drilling methods with managed pressure drilling
US12055001B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 9, 2021 |
| Grant date | Aug 6, 2024 |
| Priority date | — |
| Expiry date | Jul 15, 2042 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B37/00
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A method for drilling a wellbore comprises using drilling mud having a mud weight less than the formation pore pressure while drilling the horizontal section, to release some formation gas to mix with the drilling mud. As the mixture flows up the wellbore annulus, the resulting pressure in the vertical section is within the mud weight window (MWW) of the weak zones, thereby maintaining wellbore stability without the need for intermediate casings. The wellbore is killed by introducing a volume of heavy mud via a circulation sub in the drill string and periodically introducing additional heavy mud to fill the void left behind by the drill string as it is pulled uphole. The ratio of light mud and heavy mud in the killed well is such that the resulting pressure in the vertical section is within the MWW of the weak zones.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.