A hydraulic variable diameter centralizer

Abstract

The invention relates to a hydraulic variable-diameter centralizer used for convention oil gas well drilling and solid mineral resource well drilling, and the hydraulic variable-diameter centralizer solves the problems that an underground variable-diameter centralizer is large in starting force and short in installation distance. According to the technical scheme, sliding blocks penetrate through lower cylindrical body through grooves and are embedded into inner central tube annular grooves, an outer central tube is arranged in a revolving cylindrical body in a sleeved mode, protrusive splines outside the outer central tube are embedded into spiral grooves in the revolving cylinder body, a spring c is arranged outside the outer central tube in a sleeved mode, an upper cylindrical body is in threaded connection with a lower cylindrical body, a spring b is arranged outside the upper cylindrical body in a sleeved mode, and a sliding sleeve is arranged in the upper cylindrical body in a sleeved mode. A centralizing arm a is hinged to the triangular prism surface of the sliding sleeve, a centralizing arm b is hinged to the triangular prism surface of the lower cylindrical body and hinged to the centralizing arm a, a locking cylinder is placed in an upper cylindrical body through hole, a spring a is put in the locking cylinder, and a press plate and the upper cylindrical body are fixed through screws a. The hydraulic variable-diameter centralizer converts axial motion of the inner central tube and the outer central tube into circumferential direction rotation of the revolving cylindrical body, converts axial thrust generated by hydraulic pressure into circumferential direction centralizing force, and is reliable in supporting and large in installation distance.

Description

technical field [0001] The invention relates to a hydraulic variable-diameter centralizer used for downhole reaming of oil and gas wells and mining of deep formation minerals. Background technique [0002] In order to control and adjust the wellbore deviation during the drilling process, a large number of centralizers are used. The centralizers currently used are mainly divided into rigid centralizers and elastic centralizers. Rigid centralizers have a large supporting force, but their shape is fixed, so they cannot be used in wells. For boreholes with irregular walls, the elastic centralizer is mainly designed according to the principle of spring, which has a high restoring force, but it will generate great axial friction resistance during the running process, and the supporting force is not as good as that of the rigid centralizer. Now there are also some variable-diameter centralizers that can be started downhole, but in wells with large well deviations and horizontal wel...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a hydraulic variable-diameter centralizer in order to solve the problem of large starting force and short installation distance of the downhole variable-diameter centralizer during the drilling process.

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