CURRENT STATUS AND FUTURE PROSPECTS OF WATER JET TECHNOLOGY IN PETROLEUM ENGINEERING IN CHINA

This paper reviews the developments of investigation and application of high pressure water jet technology in both deep drilling and oil production including jet-bit drilling, extended nozzles and their combination to enhance hydraulic effectiveness at bottomhole, combined jet and mechanical drilling, new efficient jets (self-resonating cavitating jet, self-excited oscillation jet, swirling jet) used in drilling, horizontal well drilling by water jet, near wellbore plug removal with water jet, and high pressure water jet penetrating. Laboratory investigation and field application have coherently shown that high pressure jet drilling can increase the penetration rate. The hydraulic power of rock bit with extended nozzles and with crossflow hydraulics can increase by 30∼40 percent, the bit footage by 40 to 50 percent and dynamic pressure by 90 to 110 percent compared with conventional bit. Combined jet and mechanical drilling can increase drilling rate by a factor of 3 in deep wells than convention...