【摘要】 鄂尔多斯盆地Z地区上古生界下二叠统山西组(P1sx)含气砂岩主要属湖相三角洲平原分流河道沉积,是一种低孔低渗致密砂岩气藏,常规的处理解释技术很难对其进行有效地识别。开展了AVO技术预测该区有利含气砂岩的研究:先对地震叠前道集进行了精细预处理,并根据测井资料进行了AVO正演模型分析和井旁地震AVO特征分析,发现煤层对含气砂岩的AVO效应有明显的减弱或抵消效应,增加了识别气层的难度;计算了地震资料AVO属性,并且进行了有利含气砂岩的预测,其结果与已知钻井结果符合较好,预测的有利区域与地质认识基本一致。更多还原

【Abstract】 Gas-bearing sandstones in lower Permian of Shanxi Formation of Upper Paleozoic system in Z Area of Ordos Basin were mainly distributary channel deposits of lacustrine facies delta plain,which was a tight sandstone gas reservoir with low-porosity and low-permeability,usually it was very difficult for effective recognition with conventional interpretation techniques.The study was carried out to predict the advantageous gas-bearing sandstone with AVO technology in the area: seismic pre-stack gather was finely pre-processed firstly,and AVO forward model analysis and seismic AVO characteristics analysis were performed nearby the wells according to the logging data.It is found out that the coal bed has obvious weakening or counter-balance effect on AVO effect of gas-bearing sandstone,it increases the difficulty of identifying gas reservoirs;seismic data AVO attribute is computed,and advantageous gas-bearing sandstone is predicted.The predicted result is consistent with that of the known wells,and the predicted and favorable region is basically consistent with geological understanding.更多还原