Development And Application Of PDC Bit For High Temperature Geothermal Drilling

Geothermal resources are a clean,efficient and promising alternative energy source,the development of geothermal resources to form a mature high temperature geothermal drilling technology has a very broad application prospect by using oil drilling technology.The biggest problem is the high temperature formation of the thermal wear and high temperature phase transformation of drill materials in high temperature geothermal well,which usually causes the cone bit to break and the tooth fall phenomenon seriously,the seal and the bearing system premature failure,also cause severe thermal wear of the PDC bit cutting teeth.Based on the actual working conditions of high temperature geothermal drilling,carry out the failure analysis of the drill bit,research the new technology of high temperature resistant PDC drill bit and provide high efficient drilling bit products for high temperature geothermal drilling.The main research contents are as follows:1.Analysis the failure of drilling bit under high temperature geothermal drilling condition,and put forward the solution of PDC bit technology in geothermal drilling.2.Carry out the individual PDC bit structure design in geothermal well and deep stratum.3.Studied the optimization of cutting teeth and the removal of cobalt,then introduced into the PDC drilling technology for high temperature geothermal drilling.4.A new hydraulic structure of PDC bit with flat long water hole structure is proposed.The advantage of the structure is obtained by analyzing the flow field at the bottom hole,and forming a set of hydraulic structure optimization design technology,laying the foundation for the development of new products.5.Three types of high temperature geothermal drilling PDC drill products have been developed,which has been successfully applied in a country geothermal drilling,In the well temperature formation from 200 to 300,the drilling speed increase effect is obvious,compared with the similar products of foreign famous manufacturers and the same block,the average ROP is increased by about 82.6%.With the research work of this paper as the support,forming a system of high temperature geothermal well drill PDC technology system,developed a special drill series of products,and remarkable achievements have been made in actual drilling construction,which has contributed to the efficient development of geothermal resources.