预热气体对油页岩自生热原位转化效果的影响

Influence of preheated gas on the autothermic pyrolysis in‑situ conversion process(ATS)for oil shale exploitation

地下原位转化是油页岩工业化开发的必然趋势,自生热法是实现油页岩地下原位转化的一种复合高效加热方法。为探究预热阶段不同高温载气对油页岩自生热原位转化效果的影响,以我国吉林扶余地区油页岩为例,分别在预热阶段注入氮气、空气、蒸汽、二氧化碳4种高温气体进行数值模拟分析,对比最终油气产量和能量回收率的差异。以预热阶段注高温氮气组作为对照组,结果表明注高温空气、蒸汽和二氧化碳完成开采所需时间分别降低22%、39%、12%,最大能量回收率分别提高55%、86%、23%,总油收量分别降低5%、提高18%和降低11%。从开采完成时间、能量回收率及总油收量角度来看,注蒸汽预热效果最佳。因此,综合对比可得,注蒸汽预热的自生热开采方法可有效增大油收量、降低开采所需时间、提高能量利用率。

Underground in⁃situ conversion is an inevitable trend of industrialized development of oil shale,and the autothermic pyrolysis in⁃situ conversion process(ATS)is a compound and efficient heating method to realize underground in⁃situ conversion of oil shale.In order to investigate the influence of different high⁃temperature carrier gases in the preheating stage on the effect of autogenous thermal in⁃situ conversion of oil shale,this paper took the oil shale in Fuyu area of Jilin,China,as an example,and injected four high⁃temperature gases,namely,nitrogen,air,steam,and carbon dioxide,into the preheating stage to conduct numerical simulation analysis,and compared the differences in the final oil and gas yields and the energy recovery rates.Taking the high⁃temperature nitrogen injection group as the control group in the preheating stage,the results showed that the time needed to complete the extraction by injecting high⁃temperature air,steam and carbon dioxide was reduced by 22%,39%and 12%,respectively,and the maximum energy recovery rate was increased by 55%,86%and 23%,respectively,and the total oil production was reduced by 5%,increased by 18%and reduced by 11%.From the perspectives of mining completion time,energy recovery rate and total oil production,steam injection preheating had the best effect.Therefore,a comprehensive comparison showed that the autogenous thermal extraction method of steam injection preheating could effectively increase the oil production,reduce the time required for extraction,and improve the energy utilization rate.