法面扫描井间距离的解析算法

Analytical Algorithm for Normal-Plane Scanning of Interwell Distance

法面扫描是分析实钻轨迹偏离程度、邻井防碰、定向井中靶等井间关系的重要方法。然而,传统方法存在2个主要缺陷:一是采用比较井段两端点是否位于法面异侧来判别法面与比较井是否存在交点的方法不具有普遍适用性,可能会遗漏掉邻井防碰的危险点;二是用迭代法来求解法面与比较井的交点,需要进行大量的轨迹插值与比较等方面的计算,计算量大、收敛性差。为此,基于井眼轨迹的空间圆弧模型,发展完善了法面与比较井是否相交的判别方法,并研究提出了求解其交点的解析法。这些方法不需要对比较井进行插值计算,仅需要比较井的设计轨道节点或实钻轨迹测点数据就能得到准确的计算结果,大大减小了计算量。应用实例验证了研究结果的科学性和适用性。

Normal plane scanning is an important method in interwell relationship analyses such as drilling trajectory deviation ,adjacent well anti‐collision and directional well targeting .However ,the con‐ventional method has two major defects ：（1） it can determine whether normal plane has an intersection with comparison well by identifying whether both ends of comparison well section are on the different sides of the normal plane ,which may omit danger points of adjacent well anti‐collisions ;（2） the iteration method can be used for solving the intersection between normal plane and comparison well but needs complicated calculations in the track interpolation ,resulting that the convergence is usually poor .T herefore ,a method is developed based on the spatial arc model of well tracking to determine whether the normal plane is intersec‐ted with the comparison .An analytical method is proposed to solve the intersection .It does not need inter‐polation for the comparison well but can obtain accurate calculation results by using a design track node or drilling track measuring point data of the comparison well ,thus greatly reducing calculations .Its applicabil‐ities have been verified by application examples .