Research On Control Factors And Measures Of Continuous Coal Bed Methane Drainage In Hancheng Block

The continuous coal bed methane drainage is the necessary condition to guarantee steadyproduction of CBM wells. Based on CBM development geology, coal petrology, seepagemechanics, rock mechanics theory, this paper regards Hancheng block which is located in theeast margin of Ordos basin as the research object and regards structure geology, logging,fracturing and drainage dynamic information as the foundation. Through the theoretical analysis,sampling test, production test and effect evaluation, the coal bed methane well drainage standardmode in Hancheng block was established. The influences of borehole operation and groundequipment failure factors on continuous drainage were analysed, focusing on the mechanism,characteristics and influence factors of coal powder output, fracturing sand return and eccentricwear of oil tube and sucker rod. Control measures of preventing coal powder output, fracturingsand return, and eccentric wear of oil tube and sucker rod were proposed from drainage systemoptimization, well washing engineering, technology equipment optimization, perforation intervaland fracturing optimization, tubing and sucker rods optimization and anti-eccentric wearsoftware design.These control measures can prolong the pump inspection cycle. The applicationeffect of control measures is remarkable, which ensure the continuous drainage and yieldincrease of CBM wells.