霍玛吐构造带中组合油气成藏演化分析

Hydrocarbon Accumulation Assemblage and Evolution in Huomatu Structural Belt in Southern Margin of Jungar Basin

综合利用多种油气成熟度参数、包裹体显微观察、储集层沥青测试和颗粒荧光观察等,剖析了霍玛吐构造带的油气充注次序和充注史。研究认为,霍玛吐构造带原油来源于下白垩统吐谷鲁群烃源岩,天然气来源于侏罗系煤系烃源岩。霍玛吐构造带主要存在2期成藏,第一期成藏大约距今10×106a,以低成熟度原油充注为主;第二期成藏大约距今3×106a,以天然气充注为主,伴随有较高成熟度原油充注;其油气藏经历2期充注,早油晚气,后期改造调整,并局部发生气侵分馏的成藏演化过程。

In this paper, the techniques such as oil-gas maturity parameters characterization, inclusion microstructure observation, reser-voir bitumen testing and grain fluorescence are used to analyze oil and gas charging sequence and history in Huomatu structural belt. The study suggests that the oil in Huomatu structural belt comes from the source rocks of Tugulu group of Lower Cretaceous, whereas the gas from the coal-measure source rocks of Jurassic. There are two main stages of hydrocarbon accumulation in Huomatu structural belt： the first stage is about 10 Ma ago, dominated by charging of low maturity oil; the second stage is about 3 Ma ago, dominated by gas charging and ac-companied with higher maturity oil. Such an early oil and late gas charging and evolution pattern suffers late adjustment and reconstruction, with gas-invaded fractionation locally.