阆中地区须家河组烃源岩动态演化模拟

Dynamic evolution simulation of Xujiahe Formation source rocks in Langzhong Area

王东

Wang Dong

中国石化西南油气分公司勘探开发研究院，四川 成都 610041

Research Institute of Exploration and Development, Southwest Oil and Gas Company, SINOPEC, Chengdu 610041, China

随着川北元坝地区须家河组天然气勘探取得重大突破，相邻的阆中地区须家河组的油气资源潜力开始受到重视。由于前期针对研究区须家河组烃源岩生、排烃演化以及生、排烃量等方面的研究较少，制约了须家河组油气资源潜力评价。文章从研究区的基础地质特征入手，运用三维盆地模拟技术开展烃源岩生、排烃演化史研究，并最终落实资源潜力。研究表明：须家河组烃源岩具有分布广泛、厚度大、处于生烃中心、有机质丰度高、热演化程度高等特点；该组烃源岩从中侏罗世晚期开始大量生烃，到早白垩世末期生烃结束，生、排烃期与构造形成期之间匹配关系良好，有利于油气的近源成藏；该组烃源岩生、排烃能力强，单位面积累计生、排烃量分别达94.25×10⁸ m³/km²和90.18×10⁸ m³/km²，资源潜力大，须三、须四段油气勘探前景良好。

As the exploration of natural gas in Xujiahe Formation achieves a major breakthrough in Yuanba Area of northern Sichuan Basin, the oil and gas exploration prospects of Xujiahe Formation in neighboring Langzhong Area begin to receive attention. Previous studies are mainly on the basic conditions of hydrocarbon source rocks and the dynamic evolution of adjacent areas, but the study on hydrocarbon generation and expulsion evolution history of Xujiahe Formation source rocks and the quantity of hydrocarbon generation and expulsion are less, restricting the evaluation of oil and gas resource potential in Xujiahe Formation. So this paper starts from the basis geological characteristics of study area and uses 3-D basin modeling technologies to study the evolutionary history of source rocks. Finally, the resource potentials in this area are implemented. The studies show that the Xujiahe Formation source rocks have the characteristics of wide distribution, being in hydrocarbon generation center, great thickness, high abundance of organic matter and high degree of thermal evolution. The Xujiahe Formation source rocks start to generate a large amount of hydrocarbon from the late Middle Jurassic, finish to the end of Early Cretaceous. There is a good matching relationship between the period of hydrocarbon generation and expulsion and the forming time of structure, which is favorable for the hydrocarbon accumulation near sources. The Xujiahe Formation source rocks have strong hydrocarbon generation and expulsion ability and the accumulated amount of hydrocarbon generation and expulsion are respectively 9,425 million m³/km² and 9,018 million m³/km² per unit area. The resource potential of source rocks is large and Xu 3 and Xu 4 Member have good prospects of oil and gas exploration.

10.6056/dkyqt201401004