丽水36-1油气田原油轻烃地球化学特征  

Geochemical Characteristics of Light Hydrocarbons in Crude Oil From Lishui 36-1 Oil and Gas Field

作　　者：徐波 胡碧瑶 张亚男 顾智鹏 洪婧 XU Bo;HU Biyao;ZHANG Yanan;GU Zhipeng;HONG Jing(CNOOC Central Laboratory(Shanghai),CNOOC Ener Tech-Drilling and Production Co.,Shanghai 200941,China)

机构地区：[1]中海油能源发展股份有限公司工程技术分公司中海油实验中心(上海),上海200941

出　　处：《重庆科技学院学报（自然科学版）》2020年第4期12-18,共7页Journal of Chongqing University of Science and Technology：Natural Sciences Edition

基　　金：“十三五”国家科技重大专项“东海深层低渗-致密天然气勘探开发技术”(2016ZX05027-001)。

摘　　要：研究丽水36-1油气田的原油轻烃地球化学特征,主要分析其原油母质类型、次生作用、沉积环境及成熟度等特征。采集了6个原油样品,利用气相色谱仪和同位素质谱仪开展地化分析和研究。研究表明:原油轻烃组成、C7化合物(甲基环己烷、正构烷烃和二甲基环戊烷)组成、全油碳同位素指示丽水36-1油气田的原油是由煤系腐殖型有机质生成,为湖相油和煤成油的混源油;原油不存在明显的次生作用,为正常原油。利用庚烷值、异庚烷值以及二甲基戊烷参数对原油成熟度进行划分,指示原油处于成熟油阶段。研究区原油的参数K1均为1.08,与Mango提出的K1相对稳定的观点完全吻合;参数K2为0.47-0.48,结合Pr/nC(17)-Ph/nC(18)数据,进一步指示研究区的原油形成于氧化环境,有机质类型以腐殖型(Ⅲ型)为主,为陆相原油。In order to study the geochemical characteristics of light hydrocarbon in crude oil from Lishui 36-1 oil and gas field,the characteristics of the parent material type,secondary changes,sedimentary environment and maturity of crude oil in this oil field are analyzed.Geochemical analysis and research are carried out by gas chromatograph and isotope mass spectrometer through six crude oil samples.The composition of light hydrocarbons in crude oil,the composition of C7 compounds(methylcyclohexane,n-alkanes and dimethylcyclopentane),and carbon isotope of crude oil indicate that the crude oil in Lishui 36-1 oil and gas field is derived from coal-measure humic organic matter,which is a mixed source of laculofacies oil and coal-derived oil.Crude oil has no obvious secondary changes and is normal crude oil.The maturity of crude oil is classified by heptane,isoheptane and dimethyl pentane,indicating that the crude oil is in the mature stage.K1 value of crude oil in the study area are all 1.08,which is completely consistent with Mango’s view that K1 is relatively stable.K2 value is between from 0.47 to 0.48.The results of the study which combined with the data of Pr/nC17 vs Ph/n C18 indicate that the crude oil in the study area was formed in an oxidized environment.Organic matter type is mainly humic type(Ⅲtype)and crude oil is terrestrial.

关 键 词：原油轻烃 原油碳同位素 次生作用 地球化学特征 丽水凹陷 东海盆地 

分 类 号：P618[天文地球—矿床学]