准噶尔盆地南缘中二叠统烃源岩封闭体系与开放体系生烃模拟试验研究

Simulation Experiment of Open and Closed System of Permian Source Rocks in the Southern Junggar Basin

准噶尔盆地南缘地区二叠系烃源岩生烃潜力较好,部分层段达到优质烃源岩标准,勘探前景广阔。选取了南缘东部野外妖魔山和红雁池地区的野外地质剖面中二叠统不同类型干酪根的烃源岩样品,进行了开放体系与封闭体系的生烃模拟试验的研究。密闭体系的生烃模拟试验表明,南缘二叠系烃源岩Ⅰ型干酪根生油量与生气量均较高,好于Ⅱ型。并且二者的生烃演化过程也不同,Ⅰ型干酪根的镜质体反射率Ro值在1.0%左右时,吸附油量达到高峰,Ro值在1.3%左右时,排出油量达到高峰;Ⅱ型干酪根的Ro值在1.0%左右时,排出油量与吸附油量均达到高峰。开放体系模拟试验表明,不同类型干酪根的活化能存在差异,与干酪根的显微组分有关,并且从生烃转化表明,Ⅰ型干酪根的生烃转化早、快,在Ro值为0.90%左右时达到生烃高峰,Ⅱ型与Ⅲ型干酪根依次变慢。

In the south of Junggar Basin,the generation potential of the Permian source rocks were good,part of it reached the assessment standard of high quality with wide exploration prospects.According to the simulation experiment of the open system and closed system,the simulation of the Permian source rock samples of different kinds of kerogen was analyzed from Yaomoshan and Hongyanchi Areas in the east of southern Junggar Basin.The results show that the oil and gas generation quantity of the Kerogen Ⅰis larger than that of Kerogen Ⅱ.Additionally,the generation hydrocarbon evolution of both two kerogens is different.When the Ro ratio is 1.0%,the adsorption oil of Kerogen Ⅰ is at the peak,and when the Ro ratio is 1.3%,the expulsive oil of Kerogen Ⅱ is at the peak.The simulation experiment of the open system shows that active energy of different kerogens is different in virtue of their macerals.Alternatively,from the generation hydrocarbon evolution,the generation hydrocarbon transformation of the Kerogen Ⅰis faster and earlier,it is at the peak when Ro is about 0.90%,the generation of Kerogen Ⅱ and Ⅲ slows down orderly.