车排子凸起东翼中生界原油生物降解程度评价  

Evaluation of the Biodegradation of Mesozoic Crude Oils in the Eastern Chepaizi Uplift

作　　者：苏蕾 常象春 徐佑德[2] 柳忠泉[2] 史兵兵 SU Lei;CHANG XiangChun;XU YouDe;LIU ZhongQuan;SHI BingBing(College of Earth Science and Engineering,Shandong University of Science and Technology,Qingdao,Shandong 266590,China;Institute of Petroleum Exploration and Development,Shengli Oilfield Company,SINOPEC,Dongying,Shandong 257015,China)

机构地区：[1]山东科技大学地球科学与工程学院,山东青岛266590 [2]中国石化胜利油田分公司勘探开发研究院,山东东营257015

出　　处：《沉积学报》2024年第4期1422-1432,共11页Acta Sedimentologica Sinica

基　　金：国家自然科学基金项目(42072172)。

摘　　要：【目的】车排子凸起中生界稠油资源丰富,但原油生物降解严重,制约了勘探进程。【方法】为明确车排子凸起东翼中生界原油的生物降解程度,对车排子凸起东翼侏罗纪和白垩纪储层样品抽提出的饱和烃和芳香烃进行了气相色谱—质谱(GC-MS)分析,采用分子地球化学指标,对其进行定性与定量评价。【结果】通过聚类分析,将原油分为Ⅰ、Ⅱ、Ⅲ、Ⅳ四类族群。PM(Peters and Moldowan)法分析结果表明Ⅰ_(1)类和Ⅱ_(1)类原油的生物降解程度达PM7,Ⅰ_(2)类和Ⅳ类原油的生物降解程度为PM8;Ⅱ_(2)类和Ⅲ_(1)类原油的生物降解程度为PM9,Ⅲ_(2)类原油生物降解程度为PM9+。基于优化的Manco法求得的MN_(1)值介于19693~215623,Ⅰ类原油的MN_(2)值介于769~919,Ⅱ类原油的MN_(2)值介于768~907,Ⅲ类原油的MN_(2)值介于906~954,Ⅳ类原油的MN_(2)值介于774~817。同一原油族群的Manco数与原油密度、黏度、非烃和沥青质含量均呈现良好的正相关性,与总烃呈现良好的负相关性。优化的Manco法成功厘定了生物降解程度在PM7-PM9+的储层样品,与PM等级评价具有一致性。【结论】与PM法相比,优化的Manco法对原油生物降解的识别分辨率更高。通过PM法定性评价和优化Manco法定量评价相结合,可以很好地揭示原油物性的变化,对稠油区的油气勘探有重要的指导作用。[Objective]Biodegraded crude oil is commonly found in poriferous basins globally.Biodegradation will have a profound impact on the physical properties and group components of crude oil,resulting in an increase in the oil density and viscosity,an enrichment in the non-hydrocarbon,asphaltene,sulfur metallic ion content and acid val⁃ue.In recent years,the Mesozoic(Jurassic and Cretaceous)oil-bearing sandstone reservoirs in the east margin of the Chepaizi uplift have attracted much more attention due to the discovery of large quantities of crude oil,but their se⁃vere biodegradation restricts the exploration process.In order to clarify the biodegradation level of Mesozoic crude oil in the east margin of the Chepaizi uplift,the saturated hydrocarbon and the aromatic hydrocarbon fractions extracted from the reservoir samples from 10 wells in the Mesozoic east margin of Chepaezi uplift were analyzed by gas chroma⁃tography-mass spectrometry(GC-MS),and molecular biomarkers strongly resistant to biodegradation were investigat⁃ed.[Methods]Cluster analysis,a statistical method,is an effective tool to classify studied samples into different groups by their similarity distances which were calculated from the different variables investigated.Allowing for the severe oil alteration,the following nine biomarker parameters related to tricyclic terpenes(TT),tetracyclic terpenes(Tet)and triaromatic steranes(TAS)with strong biodegradation resistance were selected:(C_(19)TT+C_(20)TT)/(C_(23)TT+C_(24)TT),C_(19)TT/C_(23)TT,C_(23)TT/C_(21)TT,C_(22)TT/C_(21)TT,C_(24)TT/C_(23)TT,ETR,C_(24) Tet/C_(26)TT,C_(27) TAS/C_(28)TAS(20R),C_(26)TAS/C_(28)TAS(20S).Cluster analysis(HCA)was performed to classify the Mesozoic crude oil populations.On this basis,the biodegradation level of Mesozoic crude oil was qualitatively evaluated according to the PM(Peters and Moldowan)method and descriptive terms.Then,following the academic theory of Manco scale,eight compounds with different sensitivities to microbial degradation,which characterize progressi

关 键 词：生物降解 PM法 优化Manco法 中生界 车排子凸起 

分 类 号：P618.13[天文地球—矿床学]