深部流体对原油中生物标志化合物的影响

Effects of Deep Fluid on Biomarkers in Crude Oil

分析、对比了饱和烃和生物标志物在深部热流体作用下的变化特征后指出,在深部流体热能的影响下, m(ΣnC_(21^-))/m(ΣnC_(23^+))、m(Pr)/m(Ph)值增高,奇偶优势明显减弱,m(C_(31)藿烷)/m(C_(30)藿烷)和m(C_(35)藿烷)/m(C_(34)藿烷)变小,m(C_(27)-C_(29)甾烷20S)/m[C_(27)-C_(29)甾烷(20S+20R)]和m(C_(27)-C_(29)甾烷ββ)/m[C_(27)-C_(29)甾烷(ββ+αα)]增大,芳烃类富集。若为富氢深部热流体,m(ΣnC_(21^-))/m(ΣnC_(22^+))、m(Pr)/m(Ph)、m(Ts)/m(Ts+Tm)等也会失去指示成熟度和沉积环境的能力。在此基础上,初步提出了原油或烃源岩有机质受深部热流体改造的判识标志。

This paper presents the varied characteristics of biomarkers of saturated hydrocarbon and aromatic hydrocarbon in process of＂ deep thermal fluid. Under the impact of thermal energy of deep fluid, the values of m（∑nC21-）/m（∑nC22＋）and m（Pr）/m（Ph） increase while the n-alkane＇s odd-even carbon number predominance gets weaken; the values of m（C31 hopane）/m（C30 hopane）＇and m（C35 hopane）/m（C34 hopane） decrease, while those of m（C27-C29 sterane 20S）/m[C27-C29 sterane （20S＋20R）] and m（C27-C29 steran ββ）/m[C27-C29 steran （ββ＋αα] increase, aromatic hydrocarbons are enriched. If the deep thermal fluid is rich in hydrogen, the biomarkers like m（∑nC21-）/m（∑nC22＋）, m（Pr）/m（Ph）, m（Fs）/m（Ts＋Tm）, etc. will fail in indicating maturity and sedimentary environment. Based on these, the identified biomarkcrs of organic matter in crude oil or hydrocarbon source rock that influenced by the deep thermal fluid are proposed preliminarily in this paper.