新型钻井提速技术在南海东部古近系地层应用

针对南海东部海域恩平组、文昌组等深部古近系地层压实程度大、岩石抗压强度高，并且含硬夹层较多，地层可钻性差难题，为解决钻井作业过程中出现钻头吃入困难、机械钻速低、钻头磨损严重、起下钻频率高等一系列问题，提高对钻井效率和钻井成本控制。该文以南海东部某区块为例，通过总结以往常规钻头使用效果，并综合地层可钻性开展分析，优选出一套复合冲击器配合专用PDC钻头组合的新型钻井提速技术，并在深部古近系难钻地层进行现场应用和验证。结果表明，该钻井提速技术与邻井同垂深、同层位对比，机械钻速显著提高，钻井效率大幅提高。该钻井提速技术的成功应用可为后续类似难钻地层的提速提效提供技术参考。

Application of New Drilling Speed-increasing Technology in Paleogene Strata in Eastern South China Sea

The deep Paleogene strata such as the Enping Formation and Wenchang Formation in the eastern South China Sea are highly compacted,with high rock compressive strength,more hard interlayers,and poor drillability.A series of problems such as bit entry difficulty,low speed,serious drilling bit wear,and high frequency of tripping have restricted drilling efficiency and drilling cost.Taking a block in the eastern South China Sea as an example,through summarizing the effect of conventional drilling bits in the past and analyzing the drillability of formations comprehensively,this paper optimizes a set of high-speed drilling technology with a composite impactor and a special PDC bit combination,and carries out field application and verification in difficult-to-drill formations of deep Paleogene.Compared with the drilling speed-up technology of adjacent wells at the same vertical depth and at the same horizon,the ROP and the drilling efficiency has significantly been improved.The successful application of this drilling speedup technology can provide technical reference for the subsequent speed-up and efficiency improvement of similar difficult-to-drill formations.