Research and application on sand fishing technique in low pressure leaking wells

Research on sand fishing technique in low pressure leaking wells was conducted to solve the issues such as sand removal in these well is difficult and large amount of sand flushing fluid will fail to remove the sand depositing in well bottom but plug into formation with conventional sand flushing technique. Optimal study has been done in terms of string structure, technical mechanism, key units and related parameters of pipe string, and then a ball-valve model sand shovel was designed which can stir up the deposited sand effectively and shut down bottom valve. Field application results show that this sand fishing technique could clean up the setting sand and is featured by simple operation, reliable process, and no damage and no pollution, low cost but high benefit. This technology has brilliant application prospect in the future and is worthy of spreading.