摘要
钻井过程中形成的井眼轨迹是展布在三维空间中的一条曲线 ,在实际工作中这条曲线是通过逐点测斜工作然后选用一种井眼轨迹计算方法来确定的。提高井眼轨迹曲线的精度有两个途径 :一是减小测斜间距 ,但这将会增加工作成本 ;二是选用更切合实际的井眼轨迹计算方法。在钻井和地质工作中常用的井眼轨变计算方法有 5种 ,算法复杂程度和精度各不相同。其原理一类为将相邻两井斜测点视为一直线 ,算法较简单 ,精度差。如正切法、平衡正切法和平均角法 ;另一类则是相邻两井斜测点视为一平面曲线 ,算法稍复杂 ,精度较高。如最小曲率法和圆柱螺线法。从方法原理分析 ,平面曲线类的算法精度高于直线类的算法。文章介绍的井眼轨迹计算的积分法是一种基于空间曲线的方法 ,它将相邻两井斜测点的连线视为一渐变空间曲线 ,这将更符合钻井工作的实际 ,其精度将高于常用的井眼轨迹计算方法 ,但算法稍复杂。
The hole trajectory formed in the process of drilling is a curve distributed in three dimensions.In practice,this curve was determined by use of a hole trajectory calculation method through measuring the hole deviation points one by one.There are two ways to raising the accuracy of the hole trajectory curve:one is to shorten the distance between two hole deviation-measured points,which will increase work costs;the other is to select a hole trajectory calculation method that is more conform to the actual circumstances.There are five hole trajectory calculation methods commonly utilized for the drilling and geological works,each complex degree of algorithm and accuracy being various.One kind of these methods regards the distance between the two adjacent hole deviation-measured points as a straight line,its algorithm being relatively simple with a poor accuracy,such as tangential method,balanced tangential method and angle-averaging method;and the other kind regards the distance as a plane curve,its algorithm being slightly complex with a relatively high accuracy,such as minimum curvature method and cylinder helix method.Through analyzing the theories of these methods,it was pointed out that the accuracy of the kind of the plane curve is higher than that of the straight line.The integral method of calculating the hole trajectory introduced in the paper is a new method based on space curve and it regards the distance as a gradually changeful space curve,which is more conform to the actual drilling circumstances.The accuracy of the new method is higher than that of the commonly used calculation methods,but its algorithm is slightly complex.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2003年第z1期57-59,共3页
Natural Gas Industry
关键词
井深
井斜角
方位角
井眼轨迹
计算公式
Well depth, Deviation angle, Azimuth (well), Hole trajectory, Calculation formula, Integral method
