Reverse-circulation sand-flushing pipe column

Abstract

The invention discloses a reverse-circulation sand-flushing pipe column, and belongs to the field of oil well production. The reverse-circulation sand-flushing pipe column comprises a sleeve, a well mouth oil production tree cross, a self-sealing device, a process pipe assembly, a single oil pipe, a steering crossover coupling, a plug, a sand-flushing oil pipe and a sand-flushing pen point. When the reverse-circulation sand-flushing pipe column is used, a pump does not need to be shut down when one single oil pipe is flushed and a new single oil pipe is connected, and it can be avoided that sand suspended in sand-flushing liquid in an oil well falls back and buries underground equipment and underground sand obstruction accidents happen; after one single oil pipe is flushed, people only need to connect the upper side of the single oil pipe with the new single oil pipe through the steering crossover coupling, the single oil pipe and an outlet pipeline do not need to be detached, operation is simple, a high-pressure faucet belt does not need to be pulled, and the labor intensity of site operators can be relieved.

Description

technical field [0001] The invention relates to the field of oil well production, in particular to a reverse circulation sand flushing pipe string. Background technique [0002] Due to the geological structure and development process, in the middle and later stages of oil well development, the cementation of the oil layer is becoming looser and sand production is becoming more and more serious. It is necessary to use sand washing strings to inject sand washing fluid into the oil well to clean the oil well and remove the sand in the well. Bring them all to the ground to prevent the sand in the well from gradually settling, the sand column will increase, block the oil outlet channel, increase the flow resistance of crude oil, reduce or even stop production of the oil well, and damage the downhole equipment to cause downhole sand stuck accidents. [0003] The current sand washing string includes casing, wellhead Christmas tree spool, single tubing, blowout preventer and reverse...

AI Technical Summary

Problems solved by technology

[0006] In order to solve the problem that when the current sand washing string is used for reverse circulation sand flushing, the pump must be stopped after flushing a single oil pipe to connect another single oil pipe, which may easily cause downhole sand stuck accidents, and the removal of the oil pipe The single root process is relatively cumbersome, the operation efficiency is low, and the labor intensity of field operators is high. The embodiment of the present invention provides a reverse circulation sand flushing string

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