Well repair method for treating coalbed methane well sand burial

Abstract

The invention discloses a coalbed methane development production use, and particularly relates to a well repair technology in a coalbed methane well production process. Under the condition that a welldoes not need to be majorly repaired, the problem that a coalbed methane well oil tube column is buried by sand can be solved. A gas lift manner is firstly used for draining water remaining in an oilpipe to the ground, hydraulic column pressure borne by a fixed valve ball is unloaded, through magnetic force, a fixed valve is opened, through gas, circulation to space of sand and pulverized coal sediment space is achieved, a mixture of sand, pulverized coal and water is roiled, and the constraint of solid sediment on the oil pipe column is reduced. The method has the advantages that the characteristic that fluid flows to drive solid particles is used for relieving the constraint of the solid sediment on the oil pipe column, and the tedious heavy repair can be avoided; and the method is used for greatly saving the well repair cost, and meanwhile, the damage to the coalbed methane well capacity due to long-time shutdown can be avoided.

Description

technical field [0001] The invention belongs to the technical field of coal bed gas extraction and particularly relates to a workover method for treating sand buried coal bed gas wells. Background technique [0002] During the drainage process of coalbed methane wells, due to the compressibility of gas, it is difficult to control the gas pressure. Often shortly after drainage, coal reservoirs will emit sand and pulverized coal, which may cause the downhole pipe string to be buried by sand. , leading to the problem of not being able to pull out. The conventional method is to lift one or several oil pipes in the sand-buried upper part by undercutting drill pipes, and the sand-buried part is lifted out one by one with casing milling pipes, which belongs to the overhaul of coalbed methane wells. If this happens, the coalbed methane well will not be able to operate normally for a long time, which will cause great damage to the fracture system of the coal reservoir and reduce the...

AI Technical Summary

Problems solved by technology

If this happens, the coalbed methane well will not be able to operate normally for a long time, which will cause great damage to the fracture system of the coal reservoir and reduce the production capacity of the coalbed methane well. A series of tools such as casing milling barrel, after workover, a large number of tubing will be damaged

[0003] The above situation is a problem that can only be solved by cumbersome workover procedures, which requires a lot of financial resources and manpower. At the same time, long-term shutdown and venting of casing pressure will damage the coal reservoir and affect the productivity of the CBM well.

Images