Coal seam gas well washing tool passing through glass fiber reinforced plastics screen pipe and method

Abstract

The invention discloses a coal seam gas well washing tool passing through a glass fiber reinforced plastics screen pipe. The coal seam gas well washing tool passing through the glass fiber reinforcedplastics screen pipe comprises a washpipe, a jet-flow vibration nozzle, a waterpower blocking type spraying nozzle, a pressure adjuster and a guide head. The washpipe is arranged at the center of theglass fiber reinforced plastics screen pipe. A first elastic centering sleeve is arranged between the washpipe and the glass fiber reinforced plastics screen pipe. The washpipe is sequentially connected with the jet-flow vibration nozzle, the waterpower blocking type spraying nozzle, the pressure adjuster and the guide head. According to the coal seam gas well washing of the screen pipe, due to alarge gap of the screen pipe, the flow speed of high pressure fluid released by the washing tool lowers after the high pressure fluid passes through the screen pipe, and therefore corresponding washing effect can not be achieved. During the cleaning process, fluid space can be shrunk and extruded by movement of a waterpower blocking ring and a movable pressing sleeve, and therefore the speed of the fluid flowing through the gas of the screen pipe increases, and cleaning effect is improved. In addition, the jet cleaning effect is improved by pressure pulse mechanism. A vibration cavity is formed in a nozzle mounting body, and the cleaning effect can be improved by pressure pulse generated by the vibration cavity.

Description

technical field [0001] The invention relates to the technical field of coalbed methane mining equipment, in particular to a coalbed methane well flushing tool and method through a glass fiber reinforced plastic screen. Background technique [0002] In the process of coalbed methane development, coalbed methane is mainly adsorbed in micropores, while cleats are the main channels for coalbed methane production, and the porosity of fractures has an important impact on the permeability of coalbeds. Drilling fluid entering the fractures will pollute the reservoir in the following aspects, resulting in a decrease in reservoir permeability: ①The coal matrix absorbs the liquid and expands, squeezing the fractures, which greatly reduces the reservoir permeability, and this process is almost irreversible ②The solid phase particles (clay particles, cuttings, fly ash, etc.) in the drilling fluid block the fractures and cause the reservoir permeability to decrease; ③If the drilling fluid...

AI Technical Summary

Problems solved by technology

Due to the low jet water pressure of the well washing tool, the existence of slotted screens and the high degree of pollution near the wellbore, the well washing effect is poor, the number of well washing times increases, and it takes a long time

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