CAJ | 학술논문

精细控压钻井是一种主要用于窄密度窗口地层高效、安全钻井的新技术。该技术可精确控制环空压力，实现井底压力恒定。控压起钻过程中，起至预定井深注入重浆帽后进行常规起钻。以往注重浆期间回压控制方法不具备实际操作性，一方面没有考虑钻具内压水眼重浆进入环空造成的影响，设计内容不完善；另一方面没有实时压力控制方法。根据工程实际要求，考虑钻具内压水眼重浆、井眼实际情况、以及地层特性（碳酸盐岩地层可采用近平衡压力控制，硫化氢地层采用略过平衡压力控制），进一步优化井底压力控制。在计算注重浆和井口回压关系时，建立分段实时压力控制曲线，实现起下钻过程中井底压力平稳控制，有效避免停泵期间可能造成的溢流或者漏失，提高钻井安全性及钻井综合效率。
정세공압찬정시일충주요용우착밀도창구지층고효、안전찬정적신기술。해기술가정학공제배공압력，실현정저압력항정。공압기찬과정중，기지예정정심주입중장모후진행상규기찬。이왕주중장기간회압공제방법불구비실제조작성，일방면몰유고필찬구내압수안중장진입배공조성적영향，설계내용불완선；령일방면몰유실시압력공제방법。근거공정실제요구，고필찬구내압수안중장、정안실제정황、이급지층특성（탄산염암지층가채용근평형압력공제，류화경지층채용략과평형압력공제），진일보우화정저압력공제。재계산주중장화정구회압관계시，건립분단실시압력공제곡선，실현기하찬과정중정저압력평은공제，유효피면정빙기간가능조성적일류혹자루실，제고찬정안전성급찬정종합효솔。
Fine pressure-control drilling is a new technology for efifcient and safety drilling in the stratum with narrow-density windows. The technology enables precise control of annular pressure and realizes constant bottom hole pressure. During pressure-control trip out, drill is lifted to preset well depth, and heavy grout is iflled before conventional trip out. The back pressure control method during the previous heavy grout iflling is not operable.On one hand, the inlfuence of heavy grout from nozzle to annular space by internal pressure of drilling tools is not taken into consideration, thus design contents are incomplete.On the other hand, there is no method for real-time pressure control. Bottom hole pressure control is further optimized according to actual engineering requirements and considerations of heavy grout in nozzle of drilling tools under internal pressure, actual borehole conditions, as well as stratum features (near-balanced pressure control may be adopted for carbonate rock stratum, and slightly-over-balanced pressure control may be adopted for hydrogen sulifde stratum). For calculation of relation between heavy grout iflling and back pressure at wellhead, segmented real-time pressure control curve is established to realize stable control over bottom hole pressure during round trip, effectively avoid possible overlfow or leakage during pump shutdown, and improve drilling safety and overall efifciency.