大位移井水力延伸极限研究

HYDRAULIC EXTENDED LIMITATION OF EXTENDED-REACH WELL

依据大位移井水力学原理,首次提出了大位移井水力延伸极限的概念,并给出了计算公式及步骤,分析了地层因素、泵能力、环空压耗和岩屑床高度对大位移井水力延伸极限的影响规律,结果表明,大位移井水力延伸极限随地层安全密度窗口和额定泵压的增加而增加,随环空压耗和岩屑床高度的增加而减小。大位移井极限长度的预测以及合理进行工程设计,为减少钻井风险提供了理论指导。

The conception and calculation procedure of hydraulic limitation of extended-reach well were firstly proposed based on drilling hydraulics theorem. The effects of formation parameters, pump ability, annular pressure loss and cuttings bed height on it were also described. These parameters involved annular velocity, cuttings size and hole inclination, and so on. The calculation results showed that the value of hydraulic limitation increases with the increasing of fluid density window for safely drilling and rated pump pressure and decreases with the increasing of annular pressure loss and cuttings bed height.