碳酸盐岩缝洞型储层叠前—叠后地震综合预测方法及应用

Pre-stack and post-stack seismic comprehensive prediction method and its application in carbonate fractured-vuggy reservoirs

塔里木盆地深层碳酸盐岩缝洞型储层横向变化快、非均质性较强,缝洞间接触关系较为复杂,严重制约了后期的勘探开发部署。为此,研究了基于叠前—叠后地震资料多属性分析的缝洞型储层综合预测方法。首先,基于叠后地震资料,通过多属性对比分析,优选出分频导向相干结果作为大断裂和溶洞预测的敏感属性;其次,基于叠前宽方位地震资料,提出基于宽方位导向相位属性的各向异性强度表征方法,通过奇异值分解(SVD)计算不同方位导向相位属性的最大奇异值与奇异值之和的比值,用于表征目标储层的各向异性强度分布情况,从而作为地下裂缝的预测结果;最后,将叠后大断裂、溶洞刻画结果与叠前裂缝预测结果联合分析,并应用于塔里木盆地碳酸盐岩缝洞型储层的预测,能够清晰表征缝洞间的接触关系,与实钻井结果较为吻合,从而为后期勘探开发部署提供有力依据。

The deep carbonate fractured-vuggy reservoir in Tarim Basin is characterized by rapid lateral changes,strong heterogeneity,and complex contact relationship between fractures and caves,which seriously restrict the sub-sequent exploration and development.Thus,this paper studies a comprehensive prediction method of fractured-vuggy reservoirs based on pre-stack and post-stack seismic multi-attribute analysis.Based on the post-stack seismic data,we firstly select the multispectral geosteering coherence attributes as the sensitive attributes for large fault and cave pre-diction through multi-attribute comparative analysis.Secondly,based on pre-stack wide-azimuth seismic data,we pro-pose an anisotropic strength characterization method based on the wide-azimuth geosteering phase attributes.The sin-gular value decomposition(SVD)is used to calculate the ratio of the maximum singular value to the sum of singular values from different azimuth geosteering phase attributes.The obtained results can be used to characterize the distri-butions of anisotropic strength in the target reservoir and taken as underground fracture prediction results.Finally,the post-stack large fault and cave characterization results are combined with the pre-stack fracture prediction results for analysis,and the results can be applied to the prediction of carbonate fractured-vuggy reservoirs in Tarim Basin.The contact relationship between fractures and caves can be clearly characterized,which is more consistent with the real drilling results,thus providing a favorable basis for subsequent exploration and development.