测井资料约束的层速度反演

INTERVAL VELOCITY CONVERSION CONSTRAINED BY LOG DATA

张玉芬

Zhang Yufen

理论分析和实际经验表明,影响层速度反演正确与否和精度的主要因素有两个:一是用于反演的反射系数序列的精度;二是初始层速度值的准确度。综合运用垂向具高分辨率的测井资料和横向有较好连续性的地震资料,建立反射系数序列初始模型,经不断修改和反复迭代,可得到精度较高的反射系数序列。由于受构造起伏、岩性变化以及子波选不准等因素的影响,用常规方法求取的初始层速度常存在精度低、各道不协调等问题。利用测井资料求出的层速度作为约束条件,通过扫描自动求取剖面中各道初始层速度的方法可较好地解决这些问题。

There are two major factors that influence the correction and accuracy of interval velocity.One is the accuracy of reflection coefficient sequence used in interval velocity conversion;the other one is the accuracy of initial interval velocity.In application of vertical high resolution log data and lateral continuous seismic data,high accuracy reflection coefficient sequence could be obtained by establishing the initial model of reflection coefficient sequence.Use the interval velocity that calculated based on log data as constraint condition to obtain initial interval velocity of each channel in profile by scanning,the problem mentioned above could be solved well.

10.11743/ogg19980310