三探测器密度测井仪器的源距优化

Spacing optimization for three-detector density logging tool

本文用Monte Carlo数值模拟方法,针对探测器均在正源距范围内的三探测器密度测井仪器,计算了不同源距探测器的薄层响应曲线,不同密度地层的光子通量与源距的关系,长、中、短源距间的计数交会图。结果表明,源距与密度测井仪器的纵向分辨率、统计误差、灵敏度、泥饼补偿效果有关。为使密度测井仪器具有20cm的纵向分辨率,并有高的测量精度,长、中、短源距应分别选择38、20.5、11cm左右。

In this paper, Monte Carlo simulation is used to calculates thin bed responses for different detector spacings of longer than zero spacing, the relationships between photon flux and spacing at various formation densities, and the ＂spine-rib＂ figures for long, middle and short spacings. The results show that the spacing affects the longitudinal resolution, statistical error, sensitivity, and mudcake compensation effect of density logging tool. For a density logging tool of high-resolution （20 cm） and high measurement precision, the long, middle and short spacing should be about 38, 20.5 and 11 cm, respectively.