基于岩溶模式的溶洞储集体三维地质建模

3D modeling of cave reservoirs based on karst patterns

针对波阻抗属性可以较准确地识别大型溶洞而不能识别小型溶洞的特点,结合岩溶发育模式,分别对不同类型、不同尺度的溶洞储集体三维地质建模进行研究。结果表明:不同岩溶带溶洞储集体对应不同的波阻抗分布范围,因此对不同岩溶带采用不同波阻抗属性值截断,根据岩溶模式人机交互修正的方法建立大型溶洞模型;小型溶洞具有与大型溶洞相似的岩溶成因和发育规律,可以以不同岩溶带的大型溶洞模型作为训练图像,以单井识别的小型溶洞储集体为硬数据,以小型溶洞发育概率为软数据,利用多点地质统计学算法建立小型溶洞模型;所建立的模型能够吻合硬数据,又可以反映溶洞储集体的空间分布特征。

In this study,we built a 3D model of cave reservoirs for different types and sizes respectively based on karst patterns. Based on that impedance attribute has a good corresponding relationship with cave reservoirs,and caves have different ranges of impedance values in different karst zones,we present a method to construct a model using different seismic imped-ance truncations for different karst zones and then correct the model using prior geological patterns empirically. Small-scale caves have similar genetic type of karstification with large scale caves, so taking large-scale cave model in different karst zones as training images, we established the model of small caves using multiple point geostatistical simulation with the cave interpretation of well logs as the hard data and development probability as the soft data. This model can both match the hard data and reflect the geological distributions of cave reservoirs.