随井径与岩性变化的声波时差校正方法探讨

Research on acoustic moveout correction with variable hole diameter and lithology

(1.中国科学院地质与地球物理研究所，北京100029；2.中国石油化工股份有限公司胜利油田分公司物探研究院，山东东营257022)

Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China

声波时差测量结果受井径扩径和岩性变化的双重影响。设计了一种砂泥岩剖面的变井径、变岩性模型，分析了补偿声波测井产生的滑行波传播路径，按照费马时间最小原理推导出了同时考虑井径变化和岩性变化的声波时差补偿计算公式。根据实际测井曲线读取测井值，用经典参数进行了实例计算，得到了符合实际的声波时差补偿量。

The measurement of acoustic moveout is affected by both hole diameter enlargement and lithological change. A sand/shale profile model was designed with different hole diameters and lithologies. The propagation path of slide wave generated by compensated sonic logging is analyzed. Then, Fermat minimum time principle is used to deduce the compensation formula by considering the effect of both hole diameter and lithology. The compensation value of acoustic moveout calculated by classical parameters is coinciding with the actual data read from logging curve.