辽东湾地区是渤海海域重要的含油气区.通过该地区主干断裂活动速率计算表明,总体上自古近纪沉积期至现今断裂活动减弱;但辽中、辽东地区断裂活动强于辽西地区;就同一条断裂(带)而言,断裂的不同区段也表现出活动速率的较大差异.断裂活动与油气成藏关系分析表明,辽西地区断裂在古近纪末期中等活动速率(<25m/Ma)、新近纪以来微弱活动(<10m/Ma),主要表现为断裂对油气起到有效聚集与保存作用;辽中、辽东地区断裂在古近纪末期活动速率较高(>25m/Ma),新近纪以来仍保持中等活动速率(>15m/Ma),表现为有效的输导.但不利于油气的聚集与保存.辽中、辽东地区有利于油气聚集与保存的断裂是古近纪末期以来活动速率较小或者停止活动的断裂.%Liaodongwan Area was one of the oil-bearing areas in Bohai Bay. Through the calculation of faulting activity ratios (FAR) for all the main faults, it was indicated that FARs all decreased from Eocene, Neocene to the late Holocene. Compared to the west, higher FARs was induced in the middle and east of all the Cenozoic. As far as the same fault concerned in the area, abrupt change of FAR occurred among the different fault segments. Based on the analysis of fault activities combined with oil and gas occurrence in the area, it is realized that the faults in the west, FAR<25m/Ma and <10m/Ma in the late Eocene and Holocene, respectively, it is beneficial mainly for petroleum entrapment- In contrast, those faults in the middle and east, FAR>25m/Ma and (>15m/Ma in late Eocene and Holocene, respectively, they are beneficial petroleum migration upward only, fault traps for the petroleum accumulation.
展开▼
