井身结构优化及必封点确定方法

Optimization of Wellbore Structure and Method of Determining Setting Position for Casing

针对于深井井身结构良好的设计优化,对高效钻完井有着极为重要的作用。分析了井身结构确定原则及依据,综合考虑地层压力和岩性等影响因素,确定了主要必封点原因和类型,并分析了正常作业工况、溢流约束条件和卡钻约束条件下的必封点确定。讨论了套管层次及下深的依据,即以压力平衡、管材强度、套管磨损、拉伸载荷和耐腐蚀性能为依据来综合分析。计算了井身结合设计工程数据,合理的确定了必封点。研究表明,完善工程数据后此方法对必封点的确定在实践中更为可靠,为套管下深提供极为重要的依据。

The design optimization of deep well structure has a very important role in high efficiency drilling and completion. In this paper, the principle and basis of determining wellbore structure were analyzed; the influence of formation pressure,lithology and other factors was considered, the main causes and types of setting position were determined, and the determination processes of setting position under normal operating conditions, overflow constraints and sticking constraints were analyzed. The basis of casing layer and bottom depth were discussed, such as the pressure balance, strength of pipe, casing wear, tensile load and corrosion resistance. Calculation of the well was carried out combined with the design data of engineering, and reasonable setting position was determined. The research shows that, after improving the engineering data, this method is more reliable for determining the setting position in practice, and provides a very important basis for determining casing depth.