井眼轨迹不确定性误差校正方法

Error Correction Method of Well Position Uncertainty

为提高定向井井眼轨迹的控制精度,减小实钻定向井井眼轨迹的误差,对随钻测量(Measurement While Drilling,MWD)测斜数据校正方法进行探讨,包括轴向钻柱磁干扰校正方法、多站点钻柱磁干扰校正方法以及区域磁场测量校正方法,讨论各种校正方法的优势与不足。磁场干扰校正虽然能在一定程度上减小轴向上磁性钻铤对磁场的干扰,但是会影响井底钻具组合(Bottom Hole Assembly,BHA)的成本及性能。多站分析校正方法利用了迄今为止收集的所有可用的MWD数据,以进行最佳可能性校正,具有追溯效力的作用。但是,对于区域地层本身存在异常磁场强度的情况,需要采用现场测量参考磁场方法,这些区域的现场测量数据可以为该油田绘制出来自全球模型的一系列校正结果。此方法可以为MWD测量服务商提供更加精确的参考,对保障定向井井眼轨迹精确性具有一定的指导意义。

In order to make the trajectory more accurate,and minimize the error of well survey,this paper discussed the measures of corrections of MWD survey data including magnetic interference correction,multi-station correction and in-field reference.Although the magnetic interference correction can decrease the effect of magnetic drilling collar,it also increase the cost of the BHA and effect the optimization of BHA.So the multi-station analysis can solve this problem by collecting all available MWD data to make a best estimate.However,in some region where rocks have magnetic neither the multi-station analysis nor the magnetic interference correction can correct the survey data.In order to correct for these effects,the magnetic field has to be measured on site.The in-field reference can provide more accuracy magnetic data for MWD contractor which the global models such as BGGM cannot measure. This measure mean something to the directional drilling and MWD operation.