吐哈盆地混源型油气藏的形成、地化特征及混源比例研究

THE FORMATION AND GEOCHEMICAL BEHAVIOUR OF MIXED SOURCE-TYPE RESERVOIR AND PROPORTION RESEARCH OF MIXED SOURCE IN TUHA BASIN

吐哈盆地是在多期构造运动背景下发展起来的一个复合性含油气盆地。发育二叠系、三叠系、侏罗系多套烃源岩,分别具有多期生、排烃特点。盆地内除发现具单一成因类型的"煤型"、"油型"油气藏外,还发现了"混源型"油气藏,并且随着勘探的不断深入,此类油气藏愈来愈普遍。本文主旨其一是剖析该类油气藏的形成及地球化学特征,其二是探讨应用原油碳同位素来测算混源油混源比例之方法,并应用实验验证了该方法的可行性,从而解决了盆地内已发现混源油的混源比例问题。

Tuba basin is a composite petroliferous basin evolved in multistage tectonic movement and developed multiplex hydrocarbon source rock of Permian, Triassic and Jurassic. The peak-period of discharge and generating hydrocarbon of hydrocarbon source rock was in early, medial and later Yanshan period and Himalayan period. For the effect of tectonic movement of multistage the'coal-type'and'oil-type'reservoirs with unitary genesis have been discovered besides the mixed-source type reservoir in the basin. Along with the deepening exploration the kinds of hydrocarbon reservoirs appeared generally. One of the main purposes in the paper is to analyze the formation and geochemical behaviour of this hydrocarbon reservoirs and discuss the method which uses carbon isotope of crude oil to quantify mixed-source proportion of mixed-source oil. The feasibility of the method was verified by experiment and the mixed-source proportion have been solved for mixed-source oil discovered in the basin.