高精度随机反演方法及在苏里格气田的应用

Precision Stochastic Inversion Method and Its Application in Sulige Gas Field

苏里格气田属于低孔、低渗、非均匀性极强的砂岩岩性气藏,具有有效储层厚度小、横向变化大等特点,常规的反演技术难以满足其储层预测要求。基于常规的地震反演方法与随机模拟理论,提出一种高精度的随机反演方法。该方法首先采用随机爬山反演方法计算波阻抗数据体,然后对研究区内的伽马曲线结合波阻抗的反演结果,使用序贯指示模拟技术进行伽马反演。在苏里格气田实际应用结果表明,该方法可以很好地压制地震反演的多解性,提高分辨率,能很好地识别薄层砂体、刻画出砂体的变化情况,预测结果与实际钻井资料对比吻合率较高。

Sulige gas field is belong to sandstone lithologic gas reservoir with low porosity, low permeability andstrong heterogeneity, it has the characteristics of the effective reservoir is thin with strong lateral thickness varia-tions, the conventional inversion technique can＇ t meet the requirements for reservoir prediction in Sulige area. Ahigh precision of stochastic inversion methods based on the stochastic simulation theory with seismic inversion tech-nique was proposed. Firstly, wave impedance data was calculated by stochastic seismic inversion methods, thencombining the study area gamma curve with wave impedance inversion results using sequential indicator simulationtechnology gamma inversion conditions. Practical application in Sulige gas field shows that this method improves theresolution of reservoir and suppressed multiple solution of seismic inversion , it could be a better identification tothin sandstone, and could characterize the lateral variation of sand body better, the predict results agree well withreal well-drilling data.