Hydraulic type sleeve pipe centralizer

Abstract

The invention relates to the technical field of oil-gas field down-hole tools and provides a hydraulic type sleeve pipe centralizer. The hydraulic type sleeve pipe centralizer comprises a core shaft, a hydraulic cylinder sleeve, a shearing dowel, an expanding assisting block and a centralizer plate spring; the upper portion of the hydraulic cylinder sleeve is mounted on the upper portion of the core shaft through a first fixing assembly, a liquid inflow hole is formed in the side wall of the core shaft, and a piston cylinder is mounted in a second annular cavity; a piston rod is mounted at the lower end of the piston cylinder; the lower end of the piston rod is mounted on the outer wall of the core shaft through the shearing dowel; the upper end of the centralizer plate spring is fixedly connected with the lower end of the piston rod through a second fixing assembly; the expanding assisting block is fixedly mounted on the outer wall of the middle of the core shaft; and the lower end of the centralizer plate spring is fixedly mounted on the outer wall of the lower portion of the core shaft through a third fixing assembly. The hydraulic type sleeve pipe centralizer is compact in structure, and stabbing and scraping over the well wall cannot be caused when the device is placed into a drill hole; hydraulic expanding seal is adopted, the outer diameter after expanding seal is large, the centering effect is better, center of a down-hole horizontal-section sleeve pipe is achieved, a cement loop is uniform, and improvement of the well cementation quality is facilitated.

Description

technical field [0001] The invention relates to the technical field of downhole tools in oil and gas fields, and relates to a hydraulic casing centralizer. Background technique [0002] In oil drilling operations, the quality of horizontal well cementing directly restricts the oil production in the later stage of the oil well. At present, conventional casing centralizers such as rigid centralizers and roller centralizers are mostly used in well cementing at home and abroad. For horizontal well sections, elastic centralizers are used for cementing. However, the following problems exist in the cementing of elastic centralizers: The resistance is high and the performance is unreliable; especially for unconventional formations such as mud shale, the bearing capacity of the leaf spring of the ordinary elastic centralizer is not enough; the casing is not centered, the cementing is difficult, and the thickness of the cement sheath is uneven, which seriously affects the The quality...

AI Technical Summary

Problems solved by technology

[0003] The present invention provides a hydraulic casing centralizer, which overcomes the deficiencies of the prior art and can effectively solve the problems of conventional centralizers in the existing horizontal downhole casing process, such as large size, difficulty in running in, and easy running in. Problems such as piercing and scraping the wellbore, formation of sand plugging, insufficient bearing capacity of elastic centralizer leaf spring, poor casing centering quality, difficult cementing, and poor cementing quality

Images