银额盆地及其邻区石炭系—二叠系油气资源远景调查主要进展及成果

Main Progress and Achievements of the Permo-Carboniferous Petroleum Prospective Survey in Yine Basin and its Surrounding Areas

针对影响石炭系—二叠系油气地质条件与油气资源潜力评价的关键地质问题,开展产、学、研联合攻关,采用盆山结合、地质与地球物理结合的工作手段,在石炭纪—二叠纪盆地形成与演化、沉积体系与沉积相展布、石炭系—二叠系烃源岩评价等方面取得了系列新认识。明确了银额盆地及其邻区石炭纪—二叠纪为典型的裂谷裂陷盆地,晚石炭世—早二叠世为盆地发育的鼎盛时期,以浅海陆棚相沉积为主;发现多套厚度大、横向分布稳定,且有机质丰度中等—高,并以Ⅱ型干酪根为主的成熟—高成熟烃源岩,不存在区域变质;于上古生界风化壳钻获的天然气和原油地球化学特征指示与石炭系烃源岩具有显著亲缘关系;初步预测研究区石炭系—二叠系油气资源前景,圈定了有利勘探区和较有利勘探区。

As a production-study-research team, we solved the key problems affecting the petroleum geological conditions, and petroleum resources potential evaluation of the Permo-Carboniferous strata in Yingen-Ejina basin. Several new propositions about the formation and evolution mechanism of the basin, the distribution of sedimentary system and sedimentary facies, and source rocks have been established based on the theory of basin mountain coupling, as well as the geological and geophysical technology. The Yingen-Ejina and its surrounding area is a typical rift basin formed in Permo-Carboniferous period, and the source rocks are mainly deposited in the neritic shelf environment of Late Carboniferous and Early Permian. We found many sets of large thickness, stable lateral distribution, with little regional metamorphism, and mature-to-high-mature source rocks in the Permo- Carboniferous formation, accompanied by medium-to-high abundance marine organism and II type kerogen. Geochemical characteristics of natural gas and crude oil from the Upper Paleozoic weathered crust have significant relation with that of the Carboniferous source rocks. In addition, we forecasted the prospecting potential, favorable prospecting areas, and the relative benefit areas in the Permo-Carboniferous formation.