地质统计分析在地震资料砂泥岩分布预测中的应用

Application of geostatistical analysis in prediction of sand/shale distribution from seismic data: A case study

地质统计分析在油藏描述和地震反演中可以定量地综合不同类型的数据。采用地质统计分析,结合井孔资料,对三维地震资料进行油气藏储层构造和岩性的定量解释,可以提高预测的精确性和可靠性。简要介绍了克里金内插和随机模拟应用的方法原理,重点给出了地质统计分析的3个应用实例——时深转换,净砂岩厚度估算和砂泥岩分布预测。从VSP校正的井点时深曲线出发,采用克里金方法得到精确的速度模型,完成时深转换;结合测井数据和地震波阻抗结果,采用随机模拟方法估算净砂岩厚度和砂泥岩分布。交叉验证表明,估算结果的精度较高,取得了较好的地质成果。

Geostatistical analysis can be used to integrate different classes of information in reservoir charac- terization and seismic inversion. By virtue of geosta- tistics, well logs and 3-D seismic data can be inte- grated within reservoir research, enhancing interpre- tation accuracy.In this paper, the Kriging and sto- chastic simulation are summarized firstly, and then introduced the three case histories about the applica- tion of geostatistics in detail in time-depth conversion and prediction of thickness and sand/shale distribu- tion.To implement the time-depth conversion, an accurate velocity model is determined from time- depth curves corrected by VSP data. The sand thick- ness and sand/shale distribution are inferred by sto- chastic simulation from well logs and seismic acoustic impedance data. Cross validation is implemented.