Water drainage and gas recovery device for coal seam gas and use method of water drainage and gas recovery device

Abstract

The invention discloses a water drainage and gas recovery device for coal seam gas and a use method of the water drainage and gas recovery device and belongs to the technical field of coal seam gas exploitation. The water drainage and gas recovery device for the coal seam gas is additionally provided with a mechanical control switch, a switch on-off tool, a hollow polished rod packer and the likeon the basis of the prior art, the water drainage and gas recovery device for the coal seam gas can control on-off of the mechanical control switch on an oil pipe through lifting or lowering of a hollow polished rod. When the hollow polished rod is lifted, the switch on-off tool on the hollow polished rod can drive the mechanical control switch on the oil pipe to be turned on, thus a first annularspace can communicate with a second annular space, and through stratum energy of the coal seam gas, accumulated liquid in the second annular space enters the first annular space through the mechanical control switch, enters a hollow rod and the hollow polished rod through liquid passing holes in the hollow rod and is finally discharged into the ground water flowing course. According to the waterdrainage and gas recovery device for the coal seam gas and the use method of the water drainage and gas recovery device, the stratum energy can be sufficiently utilized to conduct water-carrying gas production, so that the exploitation cost is saved.

Description

technical field [0001] The invention relates to the technical field of coalbed methane exploitation, in particular to a coalbed methane drainage and gas recovery device and a method for using the same. Background technique [0002] Coalbed methane, also known as coalbed methane gas, is called coalbed gas in the coal industry. It is an unconventional natural gas formed during coal formation and stored in coalbeds. Most of this natural gas (70%-90%) exists in the coal matrix in the state of adsorption, a small amount exists in the coal cleats and other pores and fissures in the free state, and a small amount is dissolved in the coal seam water. The adsorption of coal makes the accumulation mechanism and development technology of coalbed methane completely different from that of conventional natural gas. [0003] In the prior art, the production of coalbed methane usually uses the rod pump of the pumping unit to drain the pressurized water in the coal reservoir, so that the pr...

AI Technical Summary

Problems solved by technology

Due to the long period of time in the middle and late stages of coalbed methane mining, the continuous operation of the oil well pump will inevitably lead to the problems of high production energy consumption and high mining costs

Images