塔中地区油气源及成藏时期研究

塔里木盆地塔中地区已发现油气藏的油气源多且多期成藏，油气藏类型也很复杂，油源对比和研究油气藏形成时期对勘探有重要指导意义。综合应用全烃地球化学方法（油气碳同位素，油岩轻烃，油岩生物标志化合物），逐步判识塔中地区油气源，确认主力烃源岩为寒武系和奥陶系的碳酸盐岩（其中的泥质灰岩评价为较有利烃源岩），存在两大成因类型油气，即高成熟早期海相有机质成因油（寒武系至下奥陶统烃源岩）和高成熟湿气（中、上奥陶统烃源岩）。在此基础上，利用储集层有机包裹体均一温度分析和排烃史模拟计算结果，认为塔中地区有３期排烃高峰及成藏期，第一期主要为中奥陶世至志留纪（加里东期），第二期为二叠纪至三叠纪，第三期为白垩纪至现今（喜山期）。高成熟湿气喜山期侵入原生残留油藏有一定普遍性，可改造稠油、软沥青，使这类油藏仍有潜在勘探前景。图３表２参４（王孝陵摘）

Oil and gas sources and forming time of oil gas pools in Tazhong area, Tarim basin.

The author progressively determines the complex oil gas sources in Tazhong area of Tarim basin by comprehensively applying whole hydrocarbon geochemistry methods, which is composed of oil gas carbon isotope composition, and light hydrocarbons and biomarkers in oil and source rocks. It shows that the main hydrocarbon source rock is Cambrian Ordovician of Paleozoic. Furthermore, the author can tell two great types of oil gas coming from Cambrian Lower Ordovician and Middle Upper Ordovician, respectively. In the meantime, sources and origins are discussed and distinguished in detail for all kinds of oil and gas in Tazhong area. In the end of the article, based on the recognition of oil gas sources, utilizing the simulation results of hydrocarbon expulsion history and analyses of homogenization temperatures of the organic matter inclusion in reservoirs, and according to practical geological conditions, the author studies and determines the formation periods of all kinds of oil and gas and pools in Tazhong area.