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鄂尔多斯盆地上古生界有石炭—二叠系煤系和石炭系碳酸盐岩两套气源岩 ,其中前者对天然气的生成贡献最大。古地质温度计测温和古地温场模拟计算结果显示出 ,在晚侏罗世—早白垩世存在异常高地温场 ,使盆地古地温场和热流值均远高于现今值。受古地温场演化史的控制 ,天然气的生成具有侏罗纪之前深成变质作用控制下的生烃演化 ,早、中侏罗世深成变质作用和局部热异常控制下的生烃演化 ,晚侏罗世—早白垩世深成变质作用和区域热变质共同控制下的生烃演化及早白垩世之后降温过程下的生烃演化 4个阶段 ;相应的烃源岩在晚三叠世局部开始进入生烃门限 ,之后随生气量的逐渐增加 ,生烃范围不断扩大 ,至早中侏罗世开始有少量天然气的排出 ,晚侏罗世受燕山中期异常热事件的强烈影响 ,在晚侏罗世—早白垩世达到生排气高峰期。并最终形成以东部为主、西部次之的广覆式资源分布特征。
The Upper Paleozoic in the Ordos Basin includes two sets of gas source rocks such as Carboniferous-Permian coal measures and Carboniferous carbonate rocks, of which the former contributed the most to natural gas generation. The results of palaeogeothermal thermometry and paleo-geothermal field simulation show that there are abnormally high geopotential temperature fields in the Late Jurassic-Early Cretaceous, which make the paleo-geothermal field and heat flow values in the basin far higher than those of today. Controlled by the evolution of paleo-geothermal field, the generation of natural gas has the hydrocarbon evolution under the control of deep metamorphism before Jurassic, the metamorphism of deep metamorphism of early and middle Jurassic and the hydrocarbon evolution under the control of local thermal anomaly, Early Cretaceous metamorphism and regional metamorphism under the common control of hydrocarbon generation evolution and early Cretaceous after the evolution of hydrocarbon evolution under the evolution of four stages; the corresponding source rocks in Late Triassic began to enter the hydrocarbon generation Afterwards, with the gradual increase of the gas production, the hydrocarbon generation range expanded continuously. As early as the Middle Jurassic, a small amount of natural gas was discharged. Late Jurassic was strongly influenced by the mid-Yanshan anomalous thermal event. During the Late Jurassic-Early Cretaceous reached the peak of raw exhaust. And finally formed the distribution characteristics of broadly-distributed resources with the eastern part as the dominant part and the western part as the second part.