Research on improving deep well coring efficiency

In order to deal with low coring efficiency in deep zone of Daqing field, the motor coring tool and high efficiency grinding coring bit are designed. The motor coring tool introduces ball dropping sub, jam reminder, inner barrel thread protector, and two-catcher assembly, which not only solves the problem of low ROP and core recovery when using conventional coring tool, but also makes jam found in time. The high efficiency grinding coring bit is durable and suitable for igneous formation. The field tests prove that the motor coring tool and high efficiency grinding coring bit have good performance and the coring efficiency in deep formation is improved.