致密砂岩储层裂缝发育带的检测和识别

四川盆地上三叠统须家河组第二段T51层砂岩是一套重要的油气储层,它由深层致密河道砂岩组成,砂岩中的裂缝发育带是最有利的油气聚集空间和运移通道.由于用常规方法从地震资料中检测和区分出裂缝发育带十分困难,作者提出首先通过沉积微相分析识别出河道砂体,然后用广义希尔伯特变换法在地震沿层水平切片上找出所有可能存在于河道砂体中的裂缝信息,最后应用地质、钻井和地震等综合信息,确定出最有可能的裂缝发育带.实际资料处理结果表明,上述思路和方法对预测致密砂岩储层中的裂缝发育带是实用的.

Detection and interpretation of fracture sets in tight sandstone reservoir

The Reservoir T51 of second member of Xujiahe Formation, Upper Triassic(T_3x~2) in Sichuan Basin is an important oil-gas reservoir. It is composed of deep buried sandstone with zones rich in fractures. As those zones are the most favorable for oil-gas accumulation or migration, so people need to detect and distinguish the zones rich in fractures from 3D seismic data. However, to detect and identify those fracture zones from seismic data are very difficult by using the traditional methods, because the seismic attribute anomalies may be caused both by fractures or lithologic changes. To solve those problems, the authors first identify the channel sandstone formation by sedimentary microfacies analysis, then, employ the method of GHT (Generalized Hilbert Transform) to detect all possible fractures information in channel sandbodies on seismic horizontal slices, and at last, use the comprehensive data including geological, drilling, well-log and seismic data to determine the most possible zones rich in fractures. The real data processing results show that the above idea and techniques are useful to predict the zone rich in fractures in tight reservior.