Application of the Technique of a PDC Bit with Rotary Cutters in Deep Formations of the Xijiang Block in the Eastern South China Sea

The poor drilling ability formation of the Xijiang block in the Eastern South China Sea, low rate of ROP, and the short footage for single bit, bring risks such as long drilling circle, high operation costs, long borehole immersion time, drill blocking and sticking. To improve the efficiency of deep stratum drilling operation, this paper analyzes the formation characteristics and the defects of the traditional PDC bit in deep formation. Furthermore, rotary cutter bit technology, which is put forward to solve the problems of low mechanical drilling speed and short drill footage and is therefore applied in Xijiang block exploratory well, has achieved significant results. The average ROP of the well section is 31.46% higher than that of the same well section of the adjacent well, and a drilling operation completed the well section with a footage of 1 421.0 m. The rate of roundtrip is 8.91 m/hr, and the whole trip drilling rate increases by 89.57% compared with the average level of adjacent wells. The drilling efficiency of the paleogene strata is effectively improved, which has great promotion value in this block.