Keywords: 
• Yuanba Gas Field /
• tight reservoir /
• drilling speed /
• high-efficiency PDC bit /
• NEW-DRILL /
• rate of penetration

Abstract: The Ziliujing Formation and Xujiahe Formation of Yuanba Gas Field is characterized by tight formation lithology, strong heterogeneity, high content of conglomerate (max. up to 50%), high formation abrasiveness, low drillability (over Level 8), and high drilling fluid density (max. up to 2.4 g/cm3), great chip-holddown effect, low rock breaking efficiency, fast roller bit wear, small footage of single bit and low comprehensive benefit. They are the main intervals which hinder acceleration of drilling rate in Yuanba Gas Field. In order to address this problem, and in line with the drilling difficulties in high pressure tight abrasive formations in the deep continent facies of Yuanba, research and analysis was conducted on rock breaking mechanism starting from rock breaking tools, and a new power tool was proposed which aims to provide continuous torque, constant RPM and bit pressure for the bit, so as to increase the rock breaking capacity of the bit, reduce drill string vibration, decrease slippage and bit pressure fluctuation during cutting, meanwhile, with high-efficiency PDC bit or impregnated diamond bit, to increase drilling efficiency. For this purpose, the new accelerating tool NEW-DRILL was field tested in Yuanba Gas Field and was successful and effective, which increased the average penetration rate of 3rd opening in Yuanba Gas Field from 0.76 m/h to 2.06 m/h and shortened the drilling cycle from 150-170 d to 90-110 d. The shortening rate was 35%, which effectively solved the technical bottleneck of accelerating drilling rate in Yuanba Gas Field. Field application shows that NEW-DRILL can effectively increase the penetration rate in continental formations and can be further promoted and used.