时深转换中的井震联合速度建模方法研究与应用现状

Research and application status of well seismic joint velocity modeling in time-depth conversion

地震波速度是联系地层界面深度与地震波反射时间的纽带,更是时深转换的桥梁.井震联合速度建模可以分别采用以地震为主的速度建模方法(叠加速度分析、偏移速度分析、层析速度反演等)和以测井为主的速度建模方法(克里金估计法、随机模拟和随机反演法等).以地震为主的速度建模方法建立的速度场横向连续性较好,但算法稳定性和纵向精度等有待进一步提高.以测井为主的速度建模方法建立的速度场精度较高,可靠性好,但计算效率仍需改善.通过加强井震资料之间在不同尺度和频率特征方面的匹配,并在相关方法中加强约束条件的使用能够有效提高井震联合速度建模的准确性和可靠性,进一步加强时深转换过程中的不确定性分析,有助于提高利用井震联合速度建模开展时深转换的精度.

Seismic velocity is not only a link between formation depth and seismic reflection time, but also a bridge of time-depth conversion, when combining well log and seismic data for velocity modeling,we can use velocity modeling toothed based on seismic data （stacking velocity analysis, migration velocity analysis, tomographic velocity inversion ） and well log data （Kriging, stochastic simulation and stochastic inversion ）. the velocity field which is built with vdocity modeling toothed based on seismic data has a good lateral continuity, but its stability and longitudinal precision still need to improve, the velocity field which is built with velocity modeling toothed based on well log data has a high precision and reliability, hut its computational efficiency also need to enhance. By strengthening scale matching and frequency matching between well log and seismic data, as well as enhancing the use of constraints in the relevant approach can improve the accuracy of well and seismic velocity modeling. Further, integrating the uncertainty analysis in the process of time-depth conversion contributes to improve the accuracy of using the well seismic joint velocity modeling to carry out time-depth conversion.