法面距离扫描法的漏洞及其完善

Vulnerability and Its Improvement for Normal Plane Distance Scanning Algorithm

法面距离计算是邻井防碰分析、实钻井眼轨迹监控的重要内容,由于井眼轨迹在数学上是三维连续光滑曲线,但是计算机只能处理离散数据,所以在计算两口井之间的法面距离时,一般使用法面距离扫描法。法面距离扫描的当前算法存在一个漏洞,当相邻的两个基准点的法面与比较井井眼轨迹一个存在交点、另一个不存在交点时,基准井井眼轨迹上在这两个基准点之间必定存在一个井身点,使得该点成为有/无交点的分界点,而当前扫描算法不能求出这样的分界点。对法面距离扫描的当前算法进行完善,增加了一段使用二分法计算分界点的程序处理单元,使得扫描算法能够快速、准确地求出分界点。使用完善后算法的计算结果数据所绘制的法面距离扫描图中的法面距离曲线准确反映了法面距离的变化,不再有信息丢失的缺陷。

Calculation on normal plane distance is the important content of anti-collision analysis of adjacent wells and drilling hole trajectory control.The hole trajectory is a 3D continue smooth curve on the mathemat-ics,but the computer can process the discrete data only.So normal plane distance scanning algorithm is used for calculating the normal plane distance between two wells.Present normal plane distance scanning has vul-nerability.When the normal plane of two adjacent reference points has one intersection point with the hole trajectory of the comparison well,there must be a well point between two reference points on the hole trajec-tory of the reference well,which becomes the demarcation point with/without intersection.However,the present algorithm can′t solve such demarcation point.Program processing unit that dichotomy is used for demarcation point calculation was introduced,so the scanning algorithm is improved to solve the demarcation point quickly and accurately.The normal plane distance curve in the scanning image drawn by the calculated data by means of the improved algorithm reflects the change of the normal plane distance accurately without the de-fects of information lost.