川东北元坝地区致密砂岩多产状裂缝刻画  

Characterization of multi-attitude fractures in tight sandstones in the Yuanba area,northeastern Sichuan Basin

作　　者：黄彦庆[1] HUANG Yan-Qing(Petroleum Exploration and Production Research Institute,SINOPEC,Beijing100083,China)

机构地区：[1]中国石化石油勘探开发研究院,北京100083

出　　处：《物探与化探》2023年第5期1189-1197,共9页Geophysical and Geochemical Exploration

基　　金：中国石化科研项目“川东北须家河组储层评价与甜点预测技术”(P19012-2)。

摘　　要：为了准确刻画川东北元坝地区上三叠统须家河组致密砂岩中不同产状裂缝的分布,提出了一种基于裂缝敏感属性无监督聚类的裂缝预测方法。在叠后地震数据优化处理的基础上,提取并优选出断缝敏感属性,采用卷积神经网络深度学习算法,学习全球海量的各种类型断层和裂缝数据库,得到断缝强度、倾角和方位体。结合高精度导向曲率属性,在PCA降维的基础上,采用基于贝叶斯概率模型的无监督聚类算法,预测了不同倾角裂缝的强度,预测结果与成像测井裂缝解释结果吻合度高,与地质认识一致性好。须三段裂缝发育程度较须二段高,须三段既发育分布于九龙山背斜东南翼断层附近的断层成因缝,也有地层挠曲较大部位的褶皱成因缝,而须二段仅发育断层附近的断层成因缝。This study proposed a fracture prediction method based on unsupervised clustering of fracture sensitivity attributes to accu-rately characterize the distribution of fractures with different attitudes in tight sandstones of the Upper Triassic Xujiahe formation in the Yuanba area,northeastern Sichuan.First,the sensitivity of fractures was extracted and selected based on the optimized post-stack seis-mic data.Then,the convolutional neural network,a deep learning algorithm,was used to learn global massive fault and fracture data-bases of various types,obtaining the intensities,dip angles,and azimuths of fractures.In combination with high-precision-guided cur-vature attributes,an unsupervised clustering algorithm based on the Bayesian probability model was used to predict the intensities of fractures with different dip angles through dimensionality reduction using principal component analysis(PCA).The prediction results are highly consistent with both the fracture interpretation results from imaging logs and the geological results.The results of this study show that the third member of the Xujiahe Formation has more developed fractures than the second member.Fractures in the third member include both the fault-induced fractures distributed near the faults in the southeast flank of the Jiulongshan anticline and the fold-induced fractures in the areas with large formation flexures.By contrast,only fault-induced fractures near the faults occur in the second member.

关 键 词：多产状裂缝 裂缝相 裂缝预测 致密砂岩 元坝地区 

分 类 号：P631.4[天文地球—地质矿产勘探]