大洋钻探随钻扩孔下套管关键技术

大洋钻探通常采用无隔水管开路钻进，护壁方式以下套管为主。常规下套管方法作业程序复杂，施工周期长，常因钻孔缩径、坍塌导致套管下不到位，给安全施工带来极大挑战。笔者对大洋钻探随钻扩孔下套管关键技术进行了详细梳理，该技术利用配套专用器具，成功实现扩孔钻进和下套管作业“合二为一”，简化了作业程序，显著缩短施工周期，解决了大洋钻探开路钻进复杂地层下套管作业难度大、风险高等技术难题，为大洋钻探深部取心提供了安全保障。

KEY TECHNOLOGY OF DRILL IN CASING IN OCEAN DRILLING

Ocean drilling usually adopts open-circuit drilling without riser, and the main wall protection method is casing. The conventional casing running method has complicated operating procedures and long construction time. The casing is often not in place due to bore shrinkage and collapse, which brings great challenges to the construction. In this paper, the key technology of drill in casing in Ocean Drilling Program is sorted out in detail. This technology uses special supporting tools to realize the “combination of drilling and casing running procedures”, which simplifies the operating procedures and significantly reduces the construction period and solves the technical problems such as the difficulty and high risk of casing running in complex formations by open-circuit drilling in ocean drilling, and provides safety guarantee for deep coring in ocean drilling.