定向钻井MWD工具面角数据分析

Analysis of MWD Tool Face Angle Data in Directional Drilling

定向钻井过程中,正确地判断滑动钻进和复合钻进井段分析钻井过程是非常必要的。通过对大量实际MWD工具面角数据的观察和归纳总结,发现了滑动钻进和复合钻进的工具面角数据特征:当滑动钻进时,工具面角是围绕均值小幅波动的平稳序列;当复合钻进时,工具面角无规则地剧烈震荡。对于给定的一个数据窗口,使用频数分析方法求出了井段工具面角均值的近似值;通过定义最小波动值,求出了偏离均值的例外点集合。根据最小井段长度限制、最多例外点个数、最小波动值等参数,提出了滑动井段的判别算法。对于MWD工具面角的历史数据或者实时数据,使用数据窗口扫描方法,能从MWD工具面角数据中正确地划分出滑动钻进井段和复合钻进井段。实际钻进数据算例表明,该算法是快速、有效的。该算法既能对MWD工具面角数据做事后分析,也能用于实时在线分析。

Correct determination of the sections of sliding drilling and compound drilling is essential for process analysis during directional drilling.Through observation and generalization of a large amount of actual MWD tool face angle data,the characteristics of tool face angle data for the sliding drilling and compound drilling are discovered:the tool face angle is a stationary sequence with small fluctuations around the mean value while sliding drilling,but it oscillates violently and irregularly while compound drilling.For a given data window,the frequency analysis method is used to calculate the approximate value of the mean tool face angle.By defining the minimum fluctuation value,the set of exception points deviating from the mean value is obtained.According to the minimum section length limit,the maximum number of exception points,the minimum fluctuation value and other parameters,the discrimination algorithm of sliding interval is proposed.For historical or real-time MWD tool face angle,the data window scanning method can correctly distinguish sliding drilling sections and compound drilling sections from the MWD tool face data.The example of actual drilling data shows that the proposed algorithm is rapid and effective.The algorithm can be applied to either post-analysis or real-time online analysis for the MWD tool face angle data.