龙门山山前带北段油气远景评价

龙门山系属上扬子地台内晚中新生代断褶活动形成的山系。川西断陷属龙门山系的前陆盆地，是地台型海相沉积和前陆型陆相沉积组成复合型的含油气区。新生代断褶构造发育程度控制了山前带构造圈闭的发育和裂缝性气藏的形成。印支晚期天井山古隆起因受喜马拉雅期强烈断褶上升活动，使原有的油气藏遭到破坏。天井山古隆起北东倾伏端的广元地区，发育隐伏断裂系伴生的背斜群，是较理想的油气聚集区。

PROSPECTIVE VALUE OF OIL AND GAS IN THE FOOTHILL BELT OF THE NORTH LONGMEN MOUNTAINS

The formation of the Longmen Mountain System is due to the fault folding on the Upper Yangtze Platform in late Mesozoic Cenozoic. The Western Sichuan fault depression belonging to the foreland basin of the Longmen Mountain System is a composite oil gas area that consists of the platform type marine sediment and foreland type continental deposit. The maturity of the fault fold structure in Cenozoic controls the development of structural traps in the foothill belt and the formation of fissured gas pools. The Tianjingshan Paleo uplift in late Indo Chinese epoch destroyed the original oil gas accumulation because of the intensive fault folding in Himalaya epoch. The Guangyuan area at the NE pitching end of the Tianjingshan Paleo uplifl is a favorable oil and gas gathering area because there developed aburied fault system and its accompanying fold group.