降温热模拟实验中烃源岩成熟度和产气率的变化特征

Characteristics of maturity and gas generating yield of source rocks in thermal simulation experiment with lowering temperature

胡国艺 李振铎 李志生 李剑 罗霞 王春怡

Hu Guoyi Li Zhenduo Li Zhisheng Li Jian Luo Xia Wang Chunyi

对鄂尔多斯盆地低成熟(=0.29%)、成熟(=0.66%)和高成熟(=1.71%)的3个煤样分别开展了降温、延长加热时间热模拟实验,研究烃源岩在降温时延长加热时间成熟度和产气率的变化特征。煤样在升温后降到一定的温度,延长加热时间烃源岩成熟度仍然发生变化,增加幅度为0.15%-0.40%。在同一温度不同时间段内,值增加的速率存在差异,前期R。值增加速率较大.随着加热时间的延长值增加的速率逐渐降低。降温延长加热时间测定的烃源岩产气率的变化特征是,早期产气率较低,随着加热时间的延长累积产气率逐渐增高。生气速率的变化特征如同值,在前期生气速率较大,随加热时间延长生气率逐渐降低。实验结果表明,烃源岩在经历高温后降到一定的温度,延长加热时间可以继续生烃,只是生气速率逐渐减小。

Thermal simulation experiments with lowering temperature and extending heating time have been performed on 3 coal samples with low maturity (=0.29%), normal maturity (=0.66%) and high maturity (=1.71%), respectively, to study the change of maturity and gas generating yield of source rocks led by extending heating time while lowering the temperature. The vitrinite reflectance () of source rocks still can increase if the heating time is extended with lowering temperature to a certain point after heating. The increment is in the range of 0.15%-0.40%. The rates of increase of value vary at different time interval at the same temperature. It is relatively large at the initial stage, but then gradually lowers with extending heating time. Gas generating yield of source rocks measured through extending heating time with lowering temperature is relatively low at the initial stage, but the cumulative gas generating yield increases gradually along with the extension of heating time. Just like value, the rate of gas generation is larger at the initial stage but then lowers with extending heating time. The experiment results show that hydrocarbon generation can go on after the temperature has been lowered to a certain point after heating if the heating time is extended, but the rate of gas generation would decrease gradually.

10.11743/ogg20060217