重晶石泥浆对随钻密度测井中探测器能窗划分的影响

The effect of barite mud on the division of the detector energy window in density logging while drilling

在随钻岩性密度测井中,地层密度和岩性的求取需要通过计算探测器某一能窗段的总计数来获取,因此,能窗的准确划分直接影响到密度值和岩性值的求取。在能窗划分过程中,泥浆类型的选择将直接影响到能窗范围的确定,利用蒙特卡罗方法模拟了在淡水泥浆和重晶石泥浆两种情况下确定的能窗范围。结果表明:重晶石泥浆下确定的能窗范围要小于淡水泥浆,而且泥浆中加入重晶石对岩性识别将产生一定影响。这对岩性密度测井的影响因素分析及进一步提高岩性密度测井的测量精度有重要意义。

In the litho-density logging, formation density and lithology were acquired by calculating the total counts in certain energy window. Therefore, the division of the energy window directly affects the evaluation of density and lithology value. In the process of the energy window division, mud type affects the determination of the range of energy window. In this work, Monte Carlo simulation method was applied to study the range of energy window regarding to water mud and barite mud, respectively. The results show that the range of the energy window with barite mud is less than that of the water mud, and lithology identification will have greater error in the barite mud. It is important to analyze influencing factors and improve the measurement accuracy of the litho-density logging.