下扬子区临古1井高研磨性地层钻井技术

High abrasiveness formation drilling technology for Lingu 1 well in the lower Yangtze area

临古1井是下扬子区中古生界地层的一口重点预探井,设计井深3 200 m。该井在泥盆系和志留系钻遇高研磨性石英砂岩和白云岩,造成钻头寿命短、磨损严重。针对高研磨性地层钻井难点,开展了岩石力学特性分析,优选T1376B型PDC钻头进行个性化设计,钻头进尺提高179%,最高机械钻速2.78 m/h。同时采用自激振荡式旋转冲击钻井技术改善底部钻具组合力学特性,延长钻头使用寿命,同比机械钻速提高36.45%,对高研磨性地层钻井提速有显著效果。

Lingu 1 well is a key exploratory well in Paleozoic formation of Yangtze area, with a design depth of 3 200 m. When drilling in the Silurian and Devonian system, the high abrasiveness quartz sandstone and dolomite were drilled. As a result, there are short life of bit and serious wear - tear. Aiming at the difficulties of high abrasiveness formation, the rock mechanics properties were analyzed, to optimize T1376B type PDC bit and conduct an individual design. As a result, the bit penetration was increased by 179%, and the highest penetration rate was 2.78 m/h. Meanwhile ,the self- excited oscilla- tion rotary percussion drilling technology was utilized to improve the mechanical characteristics of bottom hole assembly （BHA） and prolong the service life of the bit. The penetration rate was increased by 36.45% ,having a significant effect on improving drilling speed in high abrasiveness formations.