油气地质与采收率2013，Vol.20Issue(1)：107-110,4.
深井安全钻井液密度窗口影响因素
Analysis on influential factors for safe window of drilling fluid density in deep well
摘要
Abstract
Considering the pore pressure variation of sidewall rock, which is caused by drilling fluid filtering, and additional stress and strain which is caused by temperature difference between drilling fluid and formation rock, the theoretical model of variation of porosi-ty, which has considered variation of pore pressure and temperature difference, is derived, and the calculation model of safe window of drilling fluid density in deep well, which has considered variation of porosity, temperature difference and pore pressure, is finally estab-lished. Application of this calculation model shows that: when temperature difference between sidewall rock and drilling fluid in deep well is definite, with increased function of drilling fluid filtering, as increased as pore pressure of sidewall rock, the caving pressure is increased, fracturing pressure is decreased, safe window of drilling fluid density is narrowing, and unfavorable for safety drilling; and when pore pressure of sidewall rock is definite, if drilling fluid lower the temperature of sidewall rock, then as increased as temperature difference, the caving pressure is decreased, fracturing pressure is increased, safe window of drilling fluid density is widen, and favor-able for the safe drilling. Moreover, if drilling fluid rises the temperature of sidewall rock, then as increased as temperature difference, the caving pressure is increased, fracturing pressure is decreased, safe window of drilling fluid density is narrowing, and unfavorable for the safety drilling. In this paper, the effects of drilling fluid filtering and temperature difference between drilling fluid and formation rock on safe window of drilling fluid density are theoretically explained, which is a of significance to the present calculation model of safe window of drilling fluid density.关键词
深井/井壁/安全钻井液密度窗口/坍塌压力/破裂压力Key words
deep well/sidewall/safe window of drilling fluid density/caving pressure/fracturing pressure分类
能源科技引用本文复制引用
李玉伟,艾池,王志成,胡超洋,郝明,栗爽..深井安全钻井液密度窗口影响因素[J].油气地质与采收率,2013,20(1):107-110,4.基金项目
国家自然科学基金项目"水力压裂岩体损伤演化与微裂缝形成研究"(50974028),国家青年科学基金项目"基于分数阶理论泥岩动态蠕变细观损伤机理研究与套管外挤损坏判别标准制定"(51104032),黑龙江省研究生创新科研基金项目"基于分形与损伤理论的巷道围岩稳定性研究"(YJSCX2011-115HLJ). （50974028）
