Wellbore Stability Analysis of Directional Wells in Pressure Depleted Reservoirs

作者：Qiang Tan, Chen Yong-hao · 发表于：Journal of Oil and Gas Technology · 年份：2010 · 被引用次数：5 · 研究领域：Drilling and Well Engineering、Hydraulic Fracturing and Reservoir Analysis、Hydrocarbon exploration and reservoir analysis

In the late development periods of many oil and gas fields,reservoir pressure decreased to depletion,and the pressure coefficient would be reduced less than 0.5. Formation pressure reduction would result in in- situ stress changes and cause the influence on wellbore stability in drilling. The formation parameters of a normal fault structure were used to calculate the variation of collapse pressure and fracture pressure changed with deviation angle when drilling to the direction of maximum and minimum horizontal principal stress before and after pressure depletion. Calculation results show that lost circulation is main risk in depleted reservoir drilling,and it should be avoid to drill high inclined or horizontal wells to azimuth of maximum horizontal principle stress. It provides a reference for designing directional wells in depleted reservoirs.