A well cleaning process and its equipment

Abstract

A two-way well flushing process and its equipment. The process includes the following steps: assembling a sand control pipe string, connecting a top packer and a setting tool, and measuring lifting and lowering suspension weights, testing circulation functions, running down to a designed position, replacing Completion fluid, gel replacement fluid, gel breaking, well washing, ball throwing, top packer setting, seal inspection, release, shearing ball seat, pulling out and feeding drilling tools and inner pipe strings. The equipment includes a running drilling tool and a sand control string. The sand control string is connected to the running drilling tool through a top packer and a setting tool and is sent into the wellbore through the running drilling tool. The sand control string It includes an outer tubing string and an inner tubing string, the outer tubing string includes a blind pipe, a screen and a sealing tube, the inner tubing string includes a flushing pipe and an insertion seal, the outer tubing string also includes a two-way flushing assembly, the The two-way well cleaning assembly is connected to the lower end of the sealing cylinder through a check valve, so that the drilling / completion fluid in the wellbore continuously enters the inner cavity of the drilling tool.

Description

technical field [0001] The invention relates to a well-flushing process and equipment in oil exploitation, in particular to a well-flushing process and equipment capable of realizing bidirectional circulation. Background technique [0002] Well washing is a very important step in the preparation for oil extraction. see figure 1 , figure 1 It is a structural schematic diagram of well washing equipment in the prior art. Such as figure 1 As shown, in the prior art, when the sand control string 20 is run in, the drilling and completion fluid in the wellbore enters the inside of the screen 30 and the flushing pipe 40 to keep the internal and external pressure balance of the screen 30 and the flushing pipe 40; At 10 o'clock, the insertion seal 50 of the inner pipe string has formed a seal with the sealing cylinder 60 of the outer pipe string, and the drilling / completion fluid in the wellbore cannot enter the inner cavity of the drilling tool 10 . In order to ensure the safety...

AI Technical Summary

Problems solved by technology

[0017] The technical problem to be solved by the present invention is to provide a well washing process and its equipment that can conveniently realize the functions of automatic grouting and forward and reverse circulation well washing according to the needs of well washing operations, so as to solve the problems existing in the prior art. Time-sensitive and easy to pollute the surrounding environment

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