摘要
实时准确控制井筒压力对于深部地层钻井安全至关重要。结合控压钻井工艺特性,提出了井口恒压控制方法,并建立了井筒-地层耦合流动模型。研究结果表明,与井底恒压模式相比,井口恒压模式可操作性更强,控制过程中井底压力会呈规律性的波动变化,并在气体前沿运移到井口时出现一个拐点。在现场作业时,需要结合安全钻井液密度窗口确定合理的井口回压调控区间。井口回压调控区间与溢流量监测值/地层渗透率呈负相关性,而与初始井口回压呈正相关性。文中研究对于提高控压钻井作业安全性有着一定的借鉴意义。
In the process of deep drilling,the real-time and precise control of bottomhole pressure has always been a critical issue to drilling safety. Combined with managed pressure drilling( MPD) technology features,constant wellhead pressure control method is proposed. And a wellbore-formation coupling flow model based on constant wellhead pressure control method is established. The results show that the constant wellhead pressure control method has better operability compared with constant bottomhole pressure( CBHP). During the process, bottomhole pressure fluctuates regularly and an inflexion occurs when the gas flows to the wellhead. Appropriate wellhead back pressure range can also be confirmed by integrating with safe mud window. The wellhead back pressure regulating range shows a negative correlation with overflow detecting level or formation permeability,while it shows a positive correction with initial wellhead back pressure. This study has some guiding significance to enhance safety in MPD operations.
出处
《钻采工艺》
CAS
北大核心
2015年第6期4-7,129,共4页
Drilling & Production Technology
基金
国家自然科学基金重点项目"控压钻井测控理论及关键问题研究"(编号:51334003)
国家自然科学基金面上项目"深层碳酸盐岩地层与井筒耦合作用机理与压力自动控制方法研究"(编号:51274221)
"控压钻井井筒多相流体瞬态变质量流动理论及工况解释方法研究"(编号:51274045)
"基于模型预测控制理论与状态机架构的控压钻井压力控制方法研究"(编号:51374223)和"大兴场构造钻完井工艺技术研究"(编号:XNS05JS2015-37)联合资助
关键词
控压钻井
井口恒压
井底压力
井口回压
调控区间
managed pressure drilling,constant wellhead pressure,bottomhole pressure,wellhead back pressure,regulating range
