东营凹陷盐湖相天然气生成的热模拟试验

东营凹陷民丰地区沙四段是典型的盐湖相沉积,也是本区重要的烃源灶和天然气产层。为了研究不同盐类物质与烃源岩在高成熟阶段的相互作用,采用高压釜封闭体系模拟了东营凹陷盐湖相烃源岩的天然气生成过程。结果表明：碳酸盐、硫酸盐、氯化盐对烃源岩热解生成天然气有强催化作用,同烃源岩热解相比,550℃时气态烃产率分别增加了35%、77%和46%。在4组热模拟气的气态烃组成及热模拟气与民丰地区天然气的轻烃组分比较中发现,上述蒸发盐类不仅改变了气态烃产物中各单组分化合物的生成路径,影响了气态烃产物的组成,而且在盐类物质参与作用下,烃源岩热解的气态烃组成与民丰地区天然气更接近。

Thermal Simulation Experiment on the Generation of Saline Lacustrine Natural Gas in Donying Depression

In the Minfeng area of Dongying depression,the natural gas comes from the source rocks of saline lacustrine facies.In order to study the reciprocity of organic matter and evaporates of saline lacustrine in Dongying depression,the paper conducts a series of thermal simulation experiment.It is found that carbonate,sulfate and chlorate can increase the hydrocarbon gas yields.The increase of their hydrocarbon is 35%,77% and 46% respectively at 550 ℃ when the three evaporates are mixed with the source rock.By comparison with the composition and parameter of the light hydrocarbon,it is concluded that evaporate could change the way of chemical compound and promote the evolution of organic matter.Furthermore,the composition of gaseous hydrocarbons generated from the source rock with evaporates are more similar to those of natural gases found in the Minfeng area.In view of above,the conclusion of thermal simulation has an important effect on the recognition of the hydrocarbon generation in saline lacustrine and the origin of natural gas in Minfeng area.