A well completion method for coalbed methane horizontal well with FRP screen pipe

Abstract

The invention discloses a well completion method for a glass fiber reinforced plastic sieve tube of a coal bed gas horizontal well, which is characterized in that the glass fiber reinforced plastic sieve tube is adopted for carrying out well completion, a washing tube is inserted in the glass fiber reinforced plastic sieve tube, hydraulic action is applied to the stacked pulverized coal blocking a horizontal well section at the end of the glass fiber reinforced plastic sieve tube by assistance of the washing tube, and the annular space between tubular columns is separated and sealed by matching of a sealed chamber and a sealed tube so as to increase the hydraulic action effect, so that the glass fiber reinforced plastic sieve tube can be smoothly inserted, the insertion of the glass fiber reinforced plastic sieve tube in a horizontal well with a large ratio of horizontal length to vertical depth can be applicable, coal bed wall support is improved while a channel for subsequent coal bed gas reforming is provided, gel breaking and hydraulic cleaning for any well section of a coal bed can also be realized through the washing tube during well completion operation, wall cakes can be eliminated in time, the coal bed is protected, and the pollution is avoided.

Description

technical field [0001] The invention relates to the technical field of coalbed methane exploitation, in particular to a method for completing a coalbed methane horizontal well by using a glass fiber reinforced plastic screen pipe. Background technique [0002] In the initial stage of CBM horizontal well mining, open hole completion is mainly used. During the production period, pulverized coal output and coal seam collapse may easily cause accidents such as wellbore blockage and fly ash blockage of drainage pumps, which seriously affect the single well production and life of CBM wells. [0003] At present, PE screens are mainly used for the completion of coalbed methane horizontal wells, which play a certain role in solving the problem of wellbore stability and sand control. However, due to the low compressive strength of the PE pipe, it is easily deformed in the downhole and has a short validity period, so it cannot be effectively flushed. [0004] The steel pipe has a good...

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Problems solved by technology

However, due to the low compressive strength of the PE pipe, it is easy to deform in the downhole, and the validity period is short, so it cannot be used for effective well cleaning operations.

[0004] The steel pipe has a good strength index, and it is not easy to deform when it is subjected to a certain ground stress underground. At the same time, the metal thread is easy to seal, and it has a high pressure when fracturing. Underground coal mining is very unsafe. Coal cutters are mostly used for underground coal mining. When mining coal, the coal cutters will generate sparks and cause explosions when they encounter steel pipes. Another fatal flaw is that the initial investment is very large. Not suitable for use in coalbed methane development

[0005] Therefore, those skilled in the art need to solve the problems encountered in the development of coalbed methane horizontal wells, such as wellbore stability, small coal seam pressure relief area, difficulty in running completion screens, difficult removal of drilling fluid mud cake, and subsequent well cleaning. Bottleneck technical issues such as impossibility of implementation due to lack of access, short production cycle, and coal mining safety

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