During the drilling process of the shale gas wells

obtaining the high quality core samples is an important prerequisite for the reservoir evaluation. Aiming at the problems such as the long coring footage

the low core recovery and the poor efficiency of the conventional coring technology

and based on the analysis of the geological characteristics of the coring layer

we optimized and improved the tools

the bit

the parameters and the technology. In the field application of the multiple shale gas wells

the average core recovery was more than 98% and the penetration rate was up to 9m/h. The results showed that this technology had wonderful performance in improving the core recovery and the penetration rate

and successfully resolved the various problems in the process of the coring in the shale gas wells. In the meantime it provided important support for the later development of the shale gas wells.