论文详情
根据储层岩石学特征分析认为渤中B油田致密储层的主要成因为原生沉积成岩后期强压实、强胶结作用; 致密储层中局部发育相对高渗甜点储层的控制因素是沉积微相; 该地区致密砂岩中局部甜点层与致密储层的岩石物理特征差异较小, 常规地球物理方法难以区分二者。依据沉积砂体成因类型的差异, 总结了致密储层中高渗甜点层垂向叠置变化模式, 指导建立了不同储层厚度、甜点层厚度、甜点层位置、甜点层非均质性变化的等效甜点层典型模型, 并对该模型进行正演。根据反射特征差异, 遴选出对不同叠置地质模式敏感的地震属性, 并形成多敏感属性组合图版, 再利用有井监督的地质模式匹配方法预测甜点层。将致密层中不同甜点层叠置样式的地震多敏感属性组合图谱库与实际地震属性进行模式匹配, 优选和标识出实际致密层中甜点层的叠置样式组合。将上述方法应用于渤中B油田甜点层的预测, 预测结果与实钻结果吻合率较高。该方法提高了利用地震属性进行甜点预测的准确性, 为低渗致密砂岩的评价和开发提供了参考。
Petrological analysis has shown that the low-permeability genesis of Oilfield B mainly includes primary sedimentation, strong compaction, and strong cementation in late diagenesis.However, sedimentary microfacies primarily control the relatively high-permeability dessert layers developed locally in low-permeability reservoirs.In this oilfield, the petrophysical characteristics of the local dessert layers are slightly different from those of tight reservoirs.Therefore, high permeability dessert layers are difficult to distinguish using conventional geophysical methods.Based on the different geneses of sand bodies, this study first summarized the vertical superposition mode of dessert layers in a tight reservoir, established representative models with varying thicknesses of reservoir, dessert thicknesses, dessert locations, and dessert heterogeneity changes, and conducted forward modeling.Theoretical seismic attributes that were relatively sensitive to different superimposed geological models were selected, and a multi-sensitive attribute combination chart was constructed according to the different reflection characteristics.Finally, the superposition pattern of the dessert layers in the tight reservoir was identified by matching the "multi-sensitive attribute combination" chart with the actual seismic attribute.In this way, the dessert layers of Oilfield B were predicted, and the results were in accordance with the drilling.This method improved the accuracy of dessert prediction using seismic attributes and provided a new method for evaluating and developing low-permeability tight oil.