Parallel-tube snubbing pulverized coal discharging system for coal-bed gas well

Abstract

The invention discloses a parallel-tube snubbing pulverized coal discharging system for a coal-bed gas well and belongs to the technical field of coal-bed gas well and oil-gas field development. The system comprises a ground portion and a down hole portion. The ground portion comprises a solid-liquid separation unit (12), a pump truck (1), a parallel-tube self-sealing unit (15), a parallel-tube well head unit (14), an air blower (2) and a coal-bed gas recovery unit (3). The down hole portion comprises a first oil tube (7), a second oil tube (18) and a parallel-tube hydraulic jet pulverized coal flushing unit (8). The ground portion is a control mechanism of the system, and the down hole portion is an execution mechanism of the system. The invention further discloses a parallel-tube snubbing pulverized coal discharging method for the coal-bed gas well, which uses the system. By means of the system, continuous pulverized coal discharging can be achieved, the current well repair efficiency is improved, and the stability of pressure of coal-bed gas in the well and the operation safety can be guaranteed during the operation.

Description

technical field [0001] The invention relates to the technical field of coalbed methane well and oil and gas field development, in particular to a coalbed methane well parallel pipe string pulverized coal discharge system, which is mainly used for removing solid particles such as pulverized coal, coal char, coal slime and the like deposited in the coalbed methane well. Background technique [0002] Coalbed methane extraction is a process of drainage and pressure reduction. In the process of pumping and drainage, due to the influence of drilling, cementing and fracturing on the well wall and surrounding coal seams, coupled with factors such as strong drainage, as well as coal seam structure and stratigraphic structural reasons, it is inevitable to have pulverized coal, coal slime and coal. Coke and other solid substances are produced. If the solid substances produced are not brought out of the wellbore by the production fluid, but are deposited in a large amount at the bottom ...

AI Technical Summary

Problems solved by technology

[0004] In the process of realizing the present invention, the inventors have found that the prior art has at least the following problems: since the coal powder is easily suspended in water, it is difficult to determine whether the coal powder is completely fished out, the efficiency is very low and the solid particles cannot be completely cleared out; in addition During the workover process, the wellhead is completely open. On the one hand, the coalbed methane produced cannot be recycled, resulting in waste of resources, polluting the environment, and unable to guarantee operation safety; The increase of coalbed methane gas production will block the gas production channel and produce "velocity sensitive effect", which will affect the recovery of coalbed methane well production capacity

The conventional hydraulic sand washing process commonly used in oil fields will cause serious leakage of coal powder liquid due to coalbed methane wells, and the return volume is much smaller than the input volume, which not only pollutes the coal seam, but also increases the difficulty of drainage and gas recovery

In addition, the existing pulverized coal fishing operation method cannot control the liquid level of the liquid in the coalbed methane well during the workover process, resulting in wet pollution of the coal seam

Images