Abstract: Well Gao95 is a wildcat well located at Boxing low-lying area in Jiyang depression. For the complex geological structure and unclear awareness of the formation, during the drilling operation, it performed with a lot of troubles, such as high hydrogen sulphide concentration, coring bit collapse and helical centralizer dropping. The reasons of the troubles are analyzed and treatments are taken to clear the troubles, so that the well drilling operation is completed successfully, which may be invaluable experience for trouble treating during drilling in this area.