地震模糊区速度模型精细构建技术及其开发随钻应用

The technology of velocity model fine construction and application of drilling in seismic fuzzy area

LD气田受热流体上供、浅层气、微裂隙等影响,地震资料在构造主体区存在模糊区。模糊区内速度横向变化大,在时间域剖面上存在同相轴下拉,主力储层的背斜构造表现为向斜。精细的构建地震资料模糊区速度场恢复真实构造,对气田开发随钻工作有着重要的实用价值。本文通过对传统时深转换方法的分析,总结地震模糊区速度模型构建存在问题。应用虚拟井构建技术恢复背斜构造的高点,及地质模型约束层速度空间展布趋势解决模糊区内同相轴波浪跳跃问题。应用构建的速度模型对气田的调整井进行深度预测,随钻误差精度在1m以内,为海上地震模糊区深度预测工作提供了重要保障。

Because the effect of heating fluid shallow gas and micro fracture,the seismic data in main structure exiting chaotic areas in LD gas field.Because of large lateral velocity variation in seismic chaotic areas,the event is pulled down in the seismic profile of time-domain,and the anticlinal structure conducts synclinal structure of main gas reservoirs.Establish velocity model in seismic chaotic areas to restore the true structure,which is important practical for drilling of gas production.By analyzing the traditional time depth conversion methods,summarize the problems of establishing the velocity model in seismic chaotic areas.Apply the technology of building virtual wells to restore the high area of anticlinal structure,and the geological model constrains layer velocity space distribution trend to solve the event wave leap problem in seismic chaotic areas.When predict the depth of adjustment wells by applying the established velocity model,the error is within one meter with high precision,which provides an important guarantee for predict the depth in sea seismic chaotic areas.