Hydraulic casing centralizer

Abstract

The invention discloses a hydraulic casing centralizer and belongs to the field of petroleum and gas development. The centralizer comprises a center pipe, a centralizing connector, a first ball, a pin shaft, a first fixing cover, a liquid cylinder, a fixing screw, a second ball, a second fixing cover, a piston, a hydraulic channel, a valve, a screwed plug, a centralizing arm, an oblique plate and a tension spring. One end of the center pipe is connected with the centralizing connector in a sleeved mode. The other end of the center pipe is connected with the liquid cylinder in a sleeved mode. The piston is arranged between the liquid cylinder and the center pipe. The centralizing arm and the oblique plate are arranged between the centralizing connector and the liquid cylinder in sequence. According to the hydraulic casing centralizer, after cement injection, pressure accumulating is carried out in a casing, the piston pushes the oblique plate to move, the centralizing arm is pushed forcibly to move outwards to be supported to a well wall by moving of the oblique plate, a casing string is forced to be in the center, the fact that the horizontal well casing is centered is effectively guaranteed, cement ring uniformity between the casing and a well hole is guaranteed, accordingly, well cementation quality is improved, in addition, the hydraulic casing centralizer is convenient to mount and easy to use, extra construction equipment is of no need, and therefore wide application prospect is achieved.

Description

technical field [0001] The invention relates to the field of oil and gas development, in particular to a hydraulic casing centralizer. Background technique [0002] At present, there are more and more oil and gas wells developed using horizontal well technology at home and abroad, including conventional oil and gas development, coalbed methane exploration and development, shale gas exploration and development, etc. Among them, in order to ensure the cementing quality, it is necessary to straighten the casing to ensure that the casing is centered. [0003] Casing centralizers currently used include elastic centralizers, rigid centralizers, and rigid roller centralizers. Although these casing centralizers have good centralizing effects in vertical wells, they have poor effects in horizontal wells. Cementing has not been able to guarantee the quality of cementing, especially when shale gas horizontal wells and tight oil and gas horizontal wells are segmented volume fracturing,...

AI Technical Summary

Problems solved by technology

[0005] In order to solve the problem that the casing centralizers in the prior art cannot satisfy the cementing quality of horizontal wells, the embodiment of the present invention provides a hydraulic casing centralizer, which can ensure that the horizontal well casing is centered and the gap between the casing and the borehole is guaranteed. The cement sheath between them is uniform to ensure the cementing quality of horizontal wells

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