Tool for reducing equivalent circulating density

Abstract

The invention provides a tool for reducing the equivalent circulating density. The tool comprises an outer cylinder, a one-way check valve assembly, an inner shell and a piston rod, wherein the outercylinder is put in a borehole, and a first annulus is formed between the outer cylinder and the borehole; the outer cylinder is sleeved with a sealing mechanism sealed on the inner wall of the borehole, and the first annulus is separated into an upper annulus and a lower annulus; the sidewall close to the upper end of the outer cylinder is provided with jet holes communicating with the upper annulus, and the sidewall close to the lower end of the outer cylinder is provided with inflow holes communicating with the lower annulus; the one-way check valve assembly is arranged in the outer cylinder, the inner shell is connected with the lower end of the one-way check valve assembly , and a second annulus is formed between the inner shell and the outer cylinder; the sidewall of the inner shell is provided with pressure relief holes, and the bottom wall of the inner shell is provided with a through hole; the piston rod is arranged in the inner shell, the lower end of the piston rod is arranged in the through hole in a penetrating manner, and a piston is arranged at the upper end of the piston rod; and a first flow channel is arranged in the piston, and a second flow channel communicatingwith the first flow channel in a butt joint manner is arranged in the piston rod. The tool for reducing the equivalent circulating density can reduce the equivalent circulating density, realizes the purpose of depressurization and guarantees safe and efficient well drilling.

Description

technical field [0001] The invention relates to the technical field of drilling supporting equipment, in particular to a tool for reducing equivalent circulation density. Background technique [0002] The statements in this section only provide background information related to the present disclosure and may not constitute prior art. [0003] With the rapid development of the oil and gas industry, the demand for oil and gas resources continues to grow, so offshore drilling is developing rapidly, and gradually moving towards deep water and ultra-deep water. However, deepwater drilling is currently facing problems such as narrow pressure window and difficult pressure control. Therefore, in response to this problem, various technical means have been used at home and abroad to solve this problem. [0004] To solve this problem, the technologies used include hollow ball double-gradient or multi-gradient drilling and depressurization tools. For hollow ball dual-gradient or mult...

AI Technical Summary

Problems solved by technology

The depressurization tools mentioned in the former are mostly rotating moving parts inside, which are easy to wear under special working conditions in the mine, have a short service life, and are more complicated to install

The pressure-reducing tool mentioned in the latter simply uses a small nozzle, although the e

Images