【摘要】 时深转换作为联系地震与地质的桥梁,是地球物理研究的一大热点。随着渤海油田勘探开发程度的不断加深,对时深转换的要求逐渐提高。渤海Q油田目的层为明下段曲流河沉积,具有典型的低幅度构造特征,且地层速度横向变化较大,具有明显的低速异常特征。这两方面特征增加了该油田时深转换研究的难度。针对常规速度建模方法的缺陷和不足,提出了种子点约束空间插值的平均速度场建模方法。该方法首先根据地震资料并结合测井及地质分层,来确定低速异常带的分布;然后根据速度异常量的大小,在低速异常带范围内设置种子点并结合井点处的速度,进行空间约束插值,进而建立速度场并用于时深转换。从实际钻井情况来看,该方法预测精度较常规方法有了较大提高,并取得了良好的实际应用效果。更多还原

【Abstract】 As the bridge to connect seismic and geological, time-depth conversion is a hot topic of geophysical research. In recent years, with further exploration and exploitation of Bohai Oilfield, higher accuracy of time-depth conversion is required. The target zone of Q oilfield is the deposition of meandering river of Minghuazhen Formation,and it is characterized by typical low amplitude structure, large lateral variation of formation velocity and obvious low velocity anomaly. The above two features brought new challenges to the research of time-depth conversion method for this oilfield. Based on the flaw and insufficiency of conventional velocity modeling method, this paper proposed a new method that firstly determines the distribution range of low velocity anomaly by seismic data combined with logging and geological stratification, then creates seed points inside the anomaly range according to the degree of velocity anomaly, finally builds the velocity field by spatial interpolation under the restraint of velocity at seed points and well points. The velocity field can finally be used for time depth conversion. From actual drilling situation, this method can improve the prediction accuracy more greatly than conventional methods and has made a good practical application.更多还原