烃源岩解析气获取新方法研究

New Experimental Methodology Research for Adsorbed Gases on Hydrocarbon-source Rocks

新研制的解析气脱气集气装置,避免了前人装置的缺点,具有样品适应范围广、进样量大,真空破碎时间短、温度低,高真空脱气,无水集气等明显优势,从而确保了获取气体样品能够真实反映烃源岩解析气的地球化学特征。获取的解析气主要以烃类气体及二氧化碳气体为主,烃类气体相对百分含量最高可达到80%以上,可稳定检测出δ13C1～δ13C3数据,部分样品检测出δ13C4～δ13C5数据,所含地化信息丰富,完全满足了解析气地球化学研究和应用的需要。本次研究利用上述新的解析气实验地球化学技术,把气—源对比研究提升到一个崭新的境界,建立天然气气源直接对比的新方法和新思路,证实前人运用天然气碳同位素间接进行气源对比是科学可行的。同时,反证了新的解析气脱气集气装置的科学性和可靠性,为烃源岩解析气的研究和应用打下了科学的实验基础。

As compared to the device developed by our predecessors, the newly established adsorbed gas degasifica- tion-eollection device has a series of advantages such as wide sample application range, large sample inlet, high vae- cure, short-time sample smashing, low crushing temperature and water-free gas collection, which make sure the geo- chemical characteristics of acquired adsorbed gas sample is the same as the adsorbed gas on corresponding hydrocar- bon-source rock. The results show that the acquired adsorbed gases are composed mainly of hydrocarbon gas and car- bon dioxide gas, with the hydrocarbon gas accounting for more than 80%, and can be measured reliably for their δ13C1 -δ13C3 data, evenδ13C4 -δ13C5 data. The results of carbon isotope test analysis satisfy the needs for the geochem- ical study and application of adsorbed gases. The above new techniques of experimental geochemistry establish the new direct nature gas-source correlation method, prove that the old usual method of indirect nature gas-source correla- tion is scientific and authentic, and set up the experimental basis of the research and application of adsorbed gas on hydrocarbon-source rock.