简易控压方法及现场试验

华北油田部分区域在钻井过程中出现钻井液高密度时溢流、低密度时漏失以及地层压力窗口不稳定等现象,给井筒安全带来了不稳定因素。通过控压钻井技术可以有效降低这种情况带来的井控风险,但精细控压设备要求高、作业成本高,现场可实施性较低。研究了一种简易控压钻井技术,该技术在保留控压核心功能的基础上,简化了节流管汇等设备,有效降低了应用成本,有利于现场应用和推广。现场应用表明:简易控压钻井技术能够实现控压钻井的目的,发生溢流时增加井口回压,从而快速提高井底压力、缓解溢流,防止了井控升级; 同时在降低井控安全风险的前提下,通过采用低密度钻井液钻进,实现提高机械钻速的效果。

Simple MPD Drilling Technology and Field Test

During the exploration and development of Huabei Oilfield, the appearance of high density overflow, low density leakage and other formation pressure window instability, brings great instability to well control. MPD drilling, which can effectively reduce the risk caused by this situation, has some disadvantages such as high requirements of equipment, high cost and low implementation. On the basis of retaining the core function of MPD, the simple MPD drilling technology simplifies the choke manifold and other equipment, effectively reduces the application cost, and conducive to on-site application and promotion. The field application shows that the application of simple MPD drilling technology can increase the back pressure of the wellhead when the well overflow, thus rapidly increase the bottom pressure, achieve the purpose of alleviating the overflow and preventing the well control upgrade. Under the premise of reducing the risk of well control safety, the effect of increasing the rate of mechanical drilling can be achieved by drilling with low-density drilling fluid.