Up-to-Date ROP Improvement Technologies for Drilling in the Paleozoic of Shunbei Oil & Gas Field and Suggestions for Further Improvements

The reservoirs in Shunbei Oil & Gas Field are characterized by a deep burial depth of 8000−8800 m. There are many strata to cross in the drilling process, and the lithology is very complex. A persistent issue, the slow drilling speed and short bit life of Paleozoic lead to the problems of long drilling cycle and high cost, which restrict its efficient and economic development. Therefore, the characteristics of the hard-to-drill formations that influence the rock-breaking efficiency in the Paleozoic and also the difficult parts of rate of penetration(ROP) improvement were analyzed. Subsequently, ROP improvement technologies designed for drilling in the Permian, Carboniferous-Silurian, and Sangtamu Formation were summarized. Meanwhile, the ROP improvement principles and characteristics of these technologies were clarified, and the performance of the technologies in improving the ROP in the Paleozoic of Shunbei Oil & Gas Field was analyzed. On this basis, the problems with currently available ROP improvement technologies were further investigated. This work points out that the technical bottleneck restricting the development of drilling acceleration technology in Shunbei Oil & Gas Field was due to a great difference in the effect of various ROP improvement technologies, the lack of theoretical basis and an unclear drilling acceleration potential. Finally, the suggestions for further improvements of ROP improvement technologies for the Paleozoic were proposed to provide a new approach to further enhancing the rock-breaking efficiency in the Paleozoic of Shunbei Oil & Gas Field.