SINGLE-WELL DRAINAGE-PRODUCTION DEVICE AND METHOD FOR DOUBLE-LAYER SUPERPOSED COAL BED GAS SYSTEM

摘要

Disclosed are a single-well drainage-production device and method for a double-layer superposed coal bed gas system. The device comprises an upper-layer coal bed gas system extraction end (20), a lower-layer coal bed gas system extraction end (21) and a ground drive device (1), wherein an outer sleeve (10) is arranged inside a coal bed gas well, the upper-layer coal bed gas system extraction end (20) and the lower-layer coal bed gas system extraction end (21) are both arranged inside the outer sleeve (10), and an inner sleeve (9) is sleeved on an inner wall of one side of the outer sleeve (10); a pump hanging system (22) is arranged inside the inner sleeve (9), a pump hanging system (22) is also arranged in an annular space between the inner sleeve (9) and the outer sleeve (10), and both pump hanging systems (22) are connected to the ground drive device (1); and the inner sleeve (9) and the pump hanging system (22) constitute the lower-layer coal bed gas system extraction end (21), and the annular space of the inner sleeve (9) and the outer sleeve (10) and the pump hanging system (22) constitute the upper-layer coal bed gas system extraction end (20). According to the device, two independent drainage-production spaces can be respectively formed in a single shaft, such that inter-system interference during drainage-production can be prevented, and the cost can also be reduced.