WELL JET PUMPING ASSEMBLY FOR DEGASSING COAL BEDS

摘要

The invention relates to jet engineering and can be used for recovering methane from coal beds. The assembly comprises a jet pump mounted on a pipe string in a well that passes through coal beds. The length of the pipe string is greater than the depth of occurrence of the lower coal bed. A carrying ring, to which a filtering shoe is attached on a switcher, is mounted below the floor of the lower bed. A carrying ring with bypass ports is mounted on the string above the roof of the upper bed. A packer is mounted on the string below the ports above the roof of the upper bed. The housing of a pump with a seat for a removable insert having a nozzle and a mixing chamber with a diffuser is mounted on the ring. The housing has a channel for draining a mixture of working fluid and exhausted fluid and a channel for supplying the exhausted fluid, which is provided with a check valve. The housing is connected to a working fluid supply pipe that is provided on the upper end with a sealing element disposed on the ring, and an inlet funnel for receiving the removable insert. The invention makes it possible to increase the operating efficiency of the pumping assembly when the exhausted fluid contains liquid and gas phases and solid mechanical impurities.