塔里木盆地北部坳陷寒武系烃源岩特征及热演化史模拟

寒武系烃源岩是塔里木盆地北部地区海相油气最为主要的来源,长期以来—对这套烃源岩发育特征研究多停留在全盆地或单一区块分析,给油田资源评价带来了诸多不确定性。利用野外露头和新井钻探取心,在分析寒武纪沉积环境及构造格局基础上,总结北部凹陷寒武系烃源岩的发育及分布特征,对所采样品选取多参数进行评价,然后通过盆地模拟软件模拟寒武系烃源岩热演化史。样品分析结果表明,北部凹陷寒武系烃源岩厚度为160~280 m,有机碳含量均值为2.10%、镜质体反射率均值为2.09%。热史模拟结果表明,塔里木盆地北部凹陷寒武系烃源岩,自加里东中期进入成熟阶段,加里东晚期—海西早期处于生油高峰期,海西中期达到过成熟阶段,海西晚期之后源岩逐步失去生烃能力,至燕山期全部停止生烃。

Characteristics and Thermal Evolution Simulation of Cambrian Source Rocks in Northern Depression of Tarim Basin

The Cambrian source rocks are the main source of marine oil and gas in the northern region of the Tarim Basin.For a long time,the research on the development characteristics of this set of source rocks has mostly stayed in the whole basin analysis or single block analysis,which gives the resource evaluation zone of the oil field.There is a lot of uncertainty.Based on the analysis of Cambrian sedimentary environment and tectonic pattern,field outcrops and core drilling were used to summarize the development and distribution characteristics of Cambrian source rocks in the northern depression.Multiple parameters were selected for evaluation of the samples and then passed Basin simulation software simulates the thermal evolution history of Cambrian source rocks.Sample analysis results show that the thickness of Cambrian source rocks in the northern depression is 160m~280m,the average organic carbon content is 2.10%,and the average value of vitrinite reflectance is 2.09%.Thermal history simulation results show that the The source rocks of the Armenian have entered the mature stage since the middle of the Caledonian period.The late Caledonian-early Haixi period is at the peak of oil generation.The middle Haixi period has reached the mature stage.After the late Haixi period,the source rock gradually loses its hydrocarbon generation ability and reaches the Yanshan period.All source rocks stopped generating hydrocarbons.