准噶尔盆地玛湖凹陷二叠系风城组烃源岩生烃特征  

Hydrocarbon Generation Characteristics of Permian Fengcheng Formation Source Rocks in Mahu Sag,Junggar Basin

作　　者：张宇 周妮 李际 高秀伟 谢再波 马东正 陶辉飞 ZHANG Yu;ZHOU Ni;LI Ji;GAO Xiu-wei;XIE Zai-bo;MA Dong-zheng;TAO Hui-fei*(Conglomerate Reservoir Key Laboratory of Xinjiang Oilfield Company,Karamy 834000,China;Xinjiang Key Laboratory of Shale Oil,Karamy 834000,China;Experimental Testing Research Institute,Xinjiang Oilfield Company,PetroChina,Karamy 834000,China;Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China)

机构地区：[1]新疆砾岩油藏实验室,克拉玛依834000 [2]新疆页岩油重点实验室,克拉玛依834000 [3]中国石油新疆油田分公司实验检测研究院,克拉玛依834000 [4]中国科学院西北生态环境资源研究院,兰州730000

出　　处：《科学技术与工程》2024年第32期13695-13707,共13页Science Technology and Engineering

基　　金：中国石油天然气集团公司新疆重大科技专项(2017E-0401);甘肃省基础研究创新群体(22JR5RA045)。

摘　　要：玛湖凹陷风城组是目前中国已知最古老的碱湖沉积,发育优质湖相烃源岩。来自风城组的烃源岩作为准噶尔盆地油气生成的物质基础发挥了至关重要的作用。为了解该套烃源岩的生烃演化特征,应用WYMN-3型高温高压半封闭模拟实验平台对采自玛湖凹陷玛页1井风城组的烃源岩样品进行生烃模拟实验,获取生油、生气及其气体碳同位素参数,分析其生烃演化过程。结果表明:风城组风二段(P 1 f 2)泥岩在受热演化过程中以生油为主,生气为辅。在350℃时为排出油、残留油产率的高峰,分别为325.35、239.45 mg/gTOC,在高温阶段(400~500℃)仍然存在生油潜力。气态烃在375℃以后开始逐渐产出,烃类气体的来源主要为油的二次裂解。烃类气体的碳同位素序列未出现倒转现象。但在低温阶段出现了翻转现象,350℃为转折点,也是生油高峰的温度点。根据烃类产率特征、气态烃碳同位素组成以及烃类气体异构比特征可将风城组烃源岩的演化生烃过程划分为4个阶段,即干酪根最初裂解→干酪根裂解→油裂解→油气裂解。The Fengcheng Formation in Mahu Sag is currently the oldest known alkaline-lacustrine deposition in China,with well-developed high-quality lacustrine source rocks.These source rocks from the Fengcheng Formation play a crucial role as a material foundation for oil and gas production in the Junggar Basin.In order to understand the hydrocarbon generation evolution characteristics of source rocks,the WYMN-3 high temperature and high pressure semi-closed simulation experiment platform was utilized.This platform simulated the hydrocarbon generation process of source rock samples obtained from the Fengcheng Formation of Well Maye 1 in the Mahu Sag.The experiment yielded data on oil generation parameters,gas generation parameters,and the gas carbon isotope composition of source rocks.Subsequently,an analysis of the hydrocarbon generation evolution process of the source rocks was conducted.The results show that the mudstone of the P 1 f 2 is dominated by oil generation and supplemented by gas generation in the process of heat evolution.At 350℃,the yield of expelled oil and residual oil peaked at 325.35,239.45 mg/gTOC,respectively,and there is still oil generation potential in the high temperature stage(400~500℃).The gaseous hydrocarbon begins to gradually produce after 375℃,and its source is mainly the secondary cracking of oil.There is no Reversal phenomenon in the carbon isotope sequence of hydrocarbon gases.However,there is a Rollover phenomenon in the low temperature stage,350℃is the turning point,which is also the temperature point of the peak of oil generation.Based on the hydrocarbon yield,carbon isotope composition of gaseous hydrocarbons,and isomerization ratio of hydrocarbon gases,the hydrocarbon generation process of source rocks in the Fengcheng Formation can be categorized into four stages:initial kerogen cracking→kerogen cracking→oil cracking→oil and gas cracking.

关 键 词：玛湖凹陷 半封闭模拟实验 碳同位素特征 生烃演化 

分 类 号：P599[天文地球—地球化学]