Invention Grant
- Patent Title: Systems and methods for managing fluid pressure in a borehole during drilling operations
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Application No.: US16311308Application Date: 2017-07-06
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Publication No.: US11293242B2Publication Date: 2022-04-05
- Inventor: Geir K. Skaugen , Karl Erik Thoresen , Åge Kyllingstad
- Applicant: National Oilwell Varco Norway AS
- Applicant Address: NO Stavanger
- Assignee: National Oilwell Varco Norway AS
- Current Assignee: National Oilwell Varco Norway AS
- Current Assignee Address: NO Stavanger
- Agency: Conley Rose, P.C.
- International Application: PCT/US2017/040993 WO 20170706
- International Announcement: WO2018/009728 WO 20180111
- Main IPC: E21B21/08
- IPC: E21B21/08 ; E21B21/10 ; E21B41/00

Abstract:
A method for drilling a borehole includes selecting a lower pressure limit and an upper pressure limit for a drilling fluid at a drilling location in the borehole. In addition, the method includes activating a pump to circulate the drilling fluid down a drill string and up an annulus disposed about the drill string. Further, the method includes operating the pump to maintain the drilling fluid at the drilling location at a pressure between the upper and the lower pressure limits. Still further, the method includes deactivating the pump to stop circulating the drilling fluid up the annulus. The method also includes sealing the drilling fluid in the annulus at a selected time after deactivating the pump and maintaining the pressure of the drilling fluid at the drilling location between the lower and the upper pressure limits.
Public/Granted literature
- US20190242204A1 Systems and Methods for Managing Fluid Pressure in a Borehole During Drilling Operations Public/Granted day:2019-08-08
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