控压钻井技术在莺歌海盆地高温高压井中的应用

Pressure Controlled Drilling technique Application in Ying Ge Hai Basin HTHP Well

中国南海莺歌海盆地中深层高温高压区域受他源、自源以及地质构造运动影响,温度高、压力大,安全密度窗口窄,钻井过程中极易出现喷、漏等复杂局面。面对突如其来的高压及井喷,常规井控技术安全性凸显不足;窄窗口井眼复杂情况处理中,常规钻井技术能实施的处理手段有限,并且易诱发次生的粘卡等井下事故。为解决难题,规避常规钻井作业中存在的不足,引进恒定井底压力控制钻井技术(下述简称:控压钻井技术)并进行应用评价。实践证明,控压钻井技术能有效应对突发的高压,并弥补常规钻井技术在窄窗口井眼中易井下复杂化的难题,为后续海上高温高压井安全高效钻进提供指导参考。

Influenced by the allochthonous, self-originating and tectonic movement, the medium to deep HTHP area of South China Sea Ying Ge Hal basin characterized by the high temperature, high pressure and narrow window for safety mud density, as a result of which the well was vulnerable for blowout and kick during drilling operation. Encountered by the abnormal high pressure and blowout, conventional well control technology was unable to deal with the accidents. When dealing the well bore complication in the narrow mud window well, conventional drilling technology has very few limited methods, which often causing the secondary accidents such as pipe sticking and so on. In order to resolve this problem, and avoid the deficiency of the conventional drilling technology, we adopted the constant bottom-hole pressure control drilling technology, and appraised it in the drilling application. The field practice had proved that the constant bottom-hole pressure control drilling technology had effectively tackled the abnormal high pressure, and is the natural complement of the conventional drilling technology in dowohole complication issues. This field test provided the guideline for the future drilling operation in offshore HTHP wells.