CAJ | 학술논문

深水钻井地层破裂压力低、钻井液密度窗口窄，溢流时采用司钻法压井，往往未控制溢流却又诱发井漏事故。因此采用深水司钻法压井时地层受力显得尤为重要。考虑节流管汇影响，利用流体动力学，建立了深水钻井司钻法压井立管压力和地层受力计算模型，分析了深水司钻法压井中立管压力和地层压力变化规律，给出了司钻法压井过程中累计泵入长度对应的立管压力、套压、地层受力变化曲线，结合地层破裂压力极限值，确定压井过程中最优压井排量。对于压井排量和钻具组合相同的情况，司钻法压井时，套管鞋越深，套管鞋处地层受力越大；深度大的套管鞋位置出现最大压力时间要早于深度小的套管鞋位置；当天然气柱顶部达到井深某处时，某处地层受力最大；当天然气柱顶部达到井口时，套管压力最大，并且地层受力最大值总是早于套管压力最大值。
심수찬정지층파렬압력저、찬정액밀도창구착，일류시채용사찬법압정，왕왕미공제일류각우유발정루사고。인차채용심수사찬법압정시지층수력현득우위중요。고필절류관회영향，이용류체동역학，건립료심수찬정사찬법압정립관압력화지층수력계산모형，분석료심수사찬법압정중립관압력화지층압력변화규률，급출료사찬법압정과정중루계빙입장도대응적립관압력、투압、지층수력변화곡선，결합지층파렬압력겁한치，학정압정과정중최우압정배량。대우압정배량화찬구조합상동적정황，사찬법압정시，투관혜월심，투관혜처지층수력월대；심도대적투관혜위치출현최대압력시간요조우심도소적투관혜위치；당천연기주정부체도정심모처시，모처지층수력최대；당천연기주정부체도정구시，투관압력최대，병차지층수력최대치총시조우투관압력최대치。
During deepwater drilling, the formation breakdown pressure is low and the window of drilling lfuid density is narrow, so when driller’s method is used to kill a well for well kicks, the result is that the kick is not controlled but lost circulation incident may be induced. Hence, formation stress seems particularly important when driller’s method is used for well killing in deepwater drilling. This paper takes into account the effect of choke manifold, uses lfuid dynamics to build a model to calculate standpipe pressure and formation stress when driller’s method is used to kill a well in deepwater drilling. Also, this paper analyzes the varying pattern of standpipe pressure and formation stress during well killing by driller’s method in deepwater drilling, provides the changing curves of standpipe pressure, casing pressure and formation stress relative to cumulative pumping length during well killing by driller’s method, and determines the optimal kill rate during well killing in conjunction with the limit of formation breakdown pressure. When the kill rate and BHA are the same, the deeper the casing shoe is, the greater the formation stress is at the casing shoe during well killing by driller’s method. The occurrence of maximum pressure at the casing shoe of great depth is earlier than that smaller depth. When the top of gas column reaches certain point in the hole, that point shall be under the maximum pressure. When the top of gas column reaches the wellhead, the casing pressure is the greatest, and the maximum value of formation stress is always earlier than that of casing pressure.