井眼轨迹随钻测量中的测斜仪器不对中随机误差分析.docx

井眼轨迹随钻测量中的测斜仪器不对中随机误差分析陈炜卿1 , 管志川1 , 赵丽2(1 . 中国石油大学 石油工程学院 ,山东 东营 257061 ; 2 . 胜利油田 采油工艺研究院 ,山东 东营 257000)摘要 :为了更加准确地描述随钻测量时产生的井眼轨迹误差 ,利用误差分析方法对随钻测量时测量仪器与井眼轴线不重合所产生的误差进行了分析 ,并采用拉格朗日插值进行了计算 。结果表明 ,这种不对中所引起的测量误差属于 随机误差的范畴 ,该误差对井斜和方位测量结果的作用是相同的 ,且服从均匀分布 。算例分析表明 ,这种随机误差相对于系统误差所造成的井眼位置的不确定范围要小得多 。测点处的随机误差椭球的中心与测点之间的距离很近 ,但是 ,随着钻头尺寸与钻铤尺寸差别的增大 ,此距离增大 ,并且椭球的 3 个半轴也呈现相同的变化趋势 。关键词 :井眼轨迹 ; 随钻测量 ; 测斜仪 ; 测量误差 ; 随机误差 ; 误差分析中图分类号 : T E 21文献标识码 :AStocha st ic error analysis of misal ign ment bet ween a xis of incl inometeran d trajectory in process of mea suring while drill ingCH EN Wei2qing1 , GUAN Zhi2chuan1 , ZHAO Li2( 1 . Col lege of Pet roleu m En gi neeri n g i n Chi n a U ni versi t y of Pet roleu m , Dongyi n g 257061 , S han don g Prov i nce , Chi n a ;2 . Oil Prod uct ion Resea rch I nst i t ute of S hengl i Oil f iel d , Dongyi n g 257000 , S han don g Prov i nce , Chi n a)Abstract : In order to describe t he t rajectory error derived f ro m measurement while drilling more accurately , t he error causedby misalignment bet ween axis of inclino meter and borehole axis was analyzed by error analysis t heory and calculated by L a2 grange interpolatio n met hod. The result s indicate t hat t he misalignment error should be included into t he scope of stochastic error . According to t he characteristics of t his kind of error item , it will take equal effect o n inclinatio n and azimut h of t he survey result s. And t he dist ributio n feat ure of t his stochastic error belo ngs to t he uniform dist ributio n. Through analysis and co mpariso n , t his stochastic error p roduces much less uncertainty co mpared wit h systematic error . The center of stochastic error ellip soid at a survey statio n is close to t his survey statio n. Wit h t he increase of t he gap , t he distance bet ween t he cen2 ter of stochastic error ellip soid and t he correspo nding survey statio n increases too . The dimensio n of ellip soid also takes t he same variatio n tendency.