礁滩型气藏与燕山、喜山期构造体系的关系

四川盆地川东北地区上二叠统长兴组生物礁、滩型气藏和下三叠统飞仙关组鲕粒生物滩型气藏勘探在普光、毛坝取得重大突破之后,很多研究者从沉积相研究出发,都认为这些礁滩是沿广旺海槽、城口-鄂西海槽以及梁平-开江海槽坡折带分布的丘形体,油气富集与海槽相关。然而,叠加上覆燕山、喜山期的构造形迹分析则发现,这些礁滩型气藏在油气成藏运移过程中还与扭动构造体系相关,特别是与各类扭动构造体系的砥柱密切相关。据此观点进行研究进而预测：巴中、仪陇莲花状构造,中台山、绵阳旋扭构造体系的砥柱与下伏地层地震剖面丘形体叠置处有望获得重大的礁滩型油气藏发现。

RELATIONSHIP BETWEEN GAS RESERVOIRS OF REEF-BANK TYPE AND TECTONIC SYSTEMS IN THE YANSHAN AND HIMALAYAN EPOCH

After significant breakthroughs were made in exploration of the Upper Permian Changxing Formation organic reef bank gas reservoirs and the Lower Triassic Feixianguan Formation oolitic organic bank gas reservoirs in Puguang and Maoba areas in the northeastern Sichuan Basin, many researchers believed based on study of sedimentary facies that these reef banks are mounded deposits distributed along Guangwang ocean trough, Chengkou Exi ocean trough and Liangping Kaijiang ocean trough slope break zone, where the enrichment of hydrocarbons are related with the ocean troughs. However, analysis of the superimposed structures overlying the Yanshan and Himalayan structures shows that various shear structural systems especially their relatively stable parts have influenced these reef bank gas reservoirs in the process of hydrocarbon migrations. Based on this concept, it is predicted that large discoveries of reef bank oil and gas reservoirs are expected in the superimposition area between relatively stable parts of Zhongtaishan and Mianyang shear structural systems and the mounded deposits on the seismic section of the underlying strata in Bazhong and Yilong lotus form structures.