摘要
通过对多研究区的页岩气碳同位素倒转现象及成因进行总结,发现目前对页岩气碳同位素倒转成因的主流认识有扩散和吸附/解吸过程中的碳同位素分馏、初次裂解气和二次裂解气的混合以及页岩气与水和过渡金属发生反应。此外,高地温、溶解作用和构造活动也可能会对碳同位素倒转有一定的贡献。碳同位素倒转在预测页岩气高产区及资源量、压裂效果以及页岩气藏的保存条件等方面有着重要的指示意义。但目前还存在一些争议,如扩散作用和吸附/解吸作用哪个占主导地位,初次裂解气和二次裂解气的混合在什么情况下才能导致碳同位素倒转,页岩气与水和过渡金属的反应中反应物和生成物还无法确定。这些争议的解决需要广大学者进一步的研究。
Carbon isotopic reversal is a phenomenon often observed in the shale gas in some areas.Studies suggest that the reversal may come from various reasons,such as carbon isotope fractionation by diffusion and adsorption/desorption processes,mixing of primary cracking gas and secondary cracking gas and the reaction of shale gas with water and transition metals.In addition,high temperature,dissolution and tectonic activities may also contribute to some extent to carbon isotope reversal in shale gas.Carbon isotope reversal in shale gas is a significant indicator to prediction of shale gas yield zone and resource potential assessment,as well as fracturing effect and preservation conditions of shale gas reservoirs.However,there are still controversies.The dominant role of diffusion and adsorption/desorption remains uncertain;it is arguable that under what circumstances a mixture of primary cracking gas and secondary cracking gas may lead to carbon isotope reversal;and the reactants and products need to be identified in the reaction of shale gas with water and transition metals.Further studies are needed to settle these disputes.
作者
陈麦雨
徐守余
张江晖
王朝
吕召宁
CHEN Maiyu;XU Shouyu;ZHANG Jianghui;WANG Zhao;LV Zhaoning(School of Geosciences,China University of Petroleum (East China),Qingdao 266580,China)
出处
《海洋地质前沿》
CSCD
2018年第12期22-28,共7页
Marine Geology Frontiers
关键词
碳同位素
页岩气
同位素倒转
干酪根
地球化学特征
carbon isotope
shale gas
isotope reversal
Kerogen
geochemical characteristics
