随钻电阻率测井的固定探测深度合成方法  

The Synthetic Approach of Fixed Depth of Investigation for Resistivity Logging While Drilling

作　　者：段宝良[1] 宋殿光[1,2] 魏宝君 张贵宾[2] 

机构地区：[1]中国电波传播研究所,河南新乡453003 [2]中国地质大学地球物理与信息技术学院,北京海淀100083 [3]中国石油大学理学院,山东青岛266580

出　　处：《西南石油大学学报（自然科学版）》2015年第4期73-80,共8页Journal of Southwest Petroleum University(Science & Technology Edition)

基　　金：教育部新世纪优秀人才支持计划(NCET-10-0767)

摘　　要：针对随钻电磁波电阻率测井仪原始曲线探测深度不确定的问题,开展了将原始测井结果合成为具有固定探测深度曲线的研究。研究中首先采用了一种简单快速的迭代反演算法进行曲线的围岩校正处理,之后利用高斯牛顿-梯度下降反演算法对每层地层进行三参数反演,获得地层的侵入带电阻率、侵入半径和地层真电阻率,再根据提出的伪源距概念,利用获得的三参数绘制探测深度与源距、源距与视电阻率的关系图版,最终通过插值获得具有固定探测深度的测量曲线。通过一系列数值模拟发现,合成后的不同探测深度曲线在有侵地层中出现有规律的分离现象,该现象与地质特征吻合很好,相比原始曲线能更直接地反映地层侵入特性,说明本方法能够提升该类仪器的应用效果,可以与阵列感应曲线进行对比,方便地质解释人员做出更准确的地层评价。To solve the problem of uncertain investigation depth of the original logging curves electromagnetic LWD Resis- tivity instrument, this paper studied on synthesizing the original logs into curves with fixed depth of investigation. We firstly used a simple and fast iterative inversion algorithm for shoulder-bed correction, followed by Gauss Newton-gradient descent algorithms to inverse invaded formation resistivity, true formation resistivity and invasion radius for each layer. Then according to the concept of the pseudo spacing, we drew the chart of investigation depth and source spacing, source spacing and apparent resistivity by using the three parameters obtained before. Finally we obtained curves with fixed depth of investigation by interpolation. Through a series of numerical simulation, we found that the different curves which were synthesized showed the separation phenomenon with regularity in the invaded formation, which coincided with the geological characteristics well, and can reflect invasion characteristics more directly compared to the original curves. So this method could improve the application effect of this kind of instrument, and can be compared with the array induction curves, which makes geological interpretation on formation evaluation more accurately.

关 键 词：随钻电阻率测井 固定探测深度 伪源距 三参数反演 倾角和围岩校正 

分 类 号：TE122[石油与天然气工程—油气勘探] P631[天文地球—地质矿产勘探]