US 12,129,728 B2
Downhole blowout preventer and blowout prevention operation method
Lanrong Ma, Beijing (CN); Lei Gu, Beijing (CN); Huibo Yin, Beijing (CN); Xiaozhi Zheng, Beijing (CN); Guangming Cheng, Beijing (CN); and Yuequan Hou, Beijing (CN)
Assigned to CHINA PETROLEUM & CHEMICAL CORPORATION, Beijing (CN); and SINOPEC PETROLEUM ENGINEERING TECHNOLOGY RESEARCH INSTITUTE CO., LTD., Beijing (CN)
Appl. No. 18/254,420
Filed by CHINA PETROLEUM & CHEMICAL CORPORATION, Beijing (CN); and SINOPEC PETROLEUM ENGINEERING TECHNOLOGY RESEARCH INSTITUTE CO., LTD., Beijing (CN)
PCT Filed Aug. 16, 2021, PCT No. PCT/CN2021/112796
§ 371(c)(1), (2) Date May 25, 2023,
PCT Pub. No. WO2022/127155, PCT Pub. Date Jun. 23, 2022.
Claims priority of application No. 202011495723.5 (CN), filed on Dec. 17, 2020.
Prior Publication US 2024/0003215 A1, Jan. 4, 2024
Int. Cl. E21B 33/06 (2006.01); E21B 23/04 (2006.01)
CPC E21B 33/06 (2013.01) [E21B 23/0413 (2020.05)] 18 Claims
OG exemplary drawing
 
15. A blowout preventing operation method, comprising steps of:
lowering a downhole blowout preventer with a tubing column into a wellbore, wherein said downhole blowout preventer comprises a blowout preventer tubing string, said blowout preventer tubing string comprising a circulation unit, a packer unit, a ball-dropping and pressure-building device, and a mechanical pressing device, which are connected in sequence from top to bottom;
performing pressure building-up through actuating the ball-dropping and pressure-building device by throwing a ball into said blowout preventer tubing string in the event that a downhole overflow occurs during tripping, or pressing said mechanical pressing device in the event that a downhole overflow occurs during drilling;
actuating said packer unit when a pressure inside said blowout preventer tubing string reaches a first predetermined value, to seal an annulus between said blowout preventer tubing string and an external casing or borehole;
actuating said circulation unit when the pressure inside said blowout preventer tubing string reaches a second predetermined value, to create a circulation path between an interior and an exterior of said blowout preventer tubing string; and
performing a well killing operation.