Abstract：Velocity spectrum used to seismic imaging cannot usually meet requirements of horizontal well drilling. In order to adapt the need of horizontal well drilling, we use accurate velocity spectrum data with different density(500m×500m, 250m×250m, 125m×125m) but the same influent factors to build velocity field based on seismic and geology situation in the study area. We analyze the influence of interval velocity calculation method and spectrum lateral density on velocity field accuracy, which provides a foundation for targets of horizontal well drilling. The following observations are obtained based our analysis:A. when velocity lateral changes cannot be controlled by spectrum, depth prediction is uncertain. This may be because of different location of control points; B. Local velocity changes caused by velocity spectrum with low density are easily ignored; when spectrum density gets higher, velocity lateral details are more obvious, and lateral control ability of velocity spectrum is also improved and higher accuracy is obtained; C. Based on drilled well tests, interval velocity calculation by model iteration inversion is more accurate than interval velocity calculation by the Dix formula for velocity field construction, but interval velocity calculation methods have fewer influences on the velocity field accuracy.
王珊. 层速度求取方法及速度谱横向密度对速度场精度的影响[J]. 石油地球物理勘探, 2016, 51(2): 355-360,375.
Wang Shan. Influences of interval velocity calculation method and spectrum lateral density on velocity field accuracy. OGP, 2016, 51(2): 355-360,375.
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