US 11,946,334 B2
Flow splitting device for gas reverse circulation drilling
Chuanwei Zhao, Dongying (CN); Zhonghua Wu, Dongying (CN); Yanjun Zhou, Dongying (CN); Honglin Tang, Dongying (CN); Zhihe Liu, Dongying (CN); Xueliang Pei, Dongying (CN); Haoyu Sun, Dongying (CN); Zhenguo Su, Dongying (CN); Bo Kang, Dongying (CN); Hui Zhang, Dongying (CN); Huangang Zhu, Dongying (CN); Yongming Chen, Dongying (CN); and Zhongshuai Chen, Dongying (CN)
Assigned to CHINA PETROLEUM & CHEMICAL CORPORATION, Beijing (CN); SINOPEC PETROLEUM ENGINEERING TECHNOLOGY SERVICE CO., LTD, Beijing (CN); SINOPEC SHENGLI PETROLEUM ENGINEERING CO., LTD, Dongying (CN); and DRILLING TECHNOLOGY RESEARCH INSTITUTE OF SINOPEC SHENGLI PETROLEUM ENGINEERING CO., LTD, Dongying (CN)
Appl. No. 17/913,075
Filed by CHINA PETROLEUM & CHEMICAL CORPORATION, Beijing (CN); SINOPEC PETROLEUM ENGINEERING TECHNOLOGY SERVICE CO., LTD, Beijing (CN); SINOPEC SHENGLI PETROLEUM ENGINEERING CO., LTD, Dongying (CN); and DRILLING TECHNOLOGY RESEARCH INSTITUTE OF SINOPEC SHENGLI PETROLEUM ENGINEERING CO., LTD, Dongying (CN)
PCT Filed Sep. 30, 2020, PCT No. PCT/CN2020/119249
§ 371(c)(1), (2) Date Sep. 20, 2022,
PCT Pub. No. WO2021/203643, PCT Pub. Date Oct. 14, 2021.
Claims priority of application No. 202010262201.4 (CN), filed on Apr. 6, 2020.
Prior Publication US 2023/0147453 A1, May 11, 2023
Int. Cl. E21B 21/16 (2006.01); E21B 21/12 (2006.01); E21B 33/128 (2006.01)
CPC E21B 33/128 (2013.01) [E21B 21/12 (2013.01); E21B 21/16 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A flow splitting device for gas reverse circulation drilling, comprising:
an upper joint for connecting with a double-wall drill pipe;
an inner tube, which is arranged in the upper joint and defines a first passageway in communication with an inner chamber of the double-wall drill pipe, a second passageway in communication with an annular space of the double-wall drill pipe formed between the inner tube and the upper joint;
a lower joint, having an upper end fixedly connected with the upper joint and a lower end for connecting with a drill tool; and
a flow guiding member provided between the upper joint and the lower joint, for allowing gas from the annular space of the double-wall drill pipe to enter into the drill tool after passing through the second passageway, and gas from the drill tool to return to a wellhead after passing through the first passageway and the inner chamber of the double-wall drill pipe,
wherein a flexible sealing mechanism is provided on the upper joint, so that the upper joint is rotatable relative to the flexible sealing mechanism, the flexible sealing mechanism extending radially outward relative to the upper joint and the lower joint to form a sealing contact with a wellbore wall,
wherein the flexible sealing mechanism comprises a plurality of sealing units arranged on the upper joint along an axial direction, each of the sealing units including a pressing disc arranged around an outer periphery of the upper joint, and a flexible ring fixed on the pressing disc, the flexible ring extending radially outward from the pressing disc to form the sealing contact with the wellbore wall.