C_5—C_7轻烃在原油地球化学研究中的应用——以塔北隆起哈拉哈塘凹陷奥陶系原油为例  

Application of C_5-C_7 Light Hydrocarbons in Geochemical Studies: A Case Study of Ordovician Crude Oils from the Halahatang Depression,Tabei Uplift

作　　者：程斌[1] 王铁冠[1] 常象春[1,2] 

机构地区：[1]中国石油大学油气资源与探测国家重点实验室,北京102249 [2]山东科技大学,山东青岛266510

出　　处：《天然气地球科学》2013年第2期398-405,共8页Natural Gas Geoscience

基　　金：中国博士后科学基金(编号:20110490539;2012750190);教育部科学技术重点项目(编号:212100)联合资助

摘　　要：以C5—C7轻烃化合物为工具进行原油成熟度、烃源岩有机质类型、原油生成温度等方面的地球化学研究。哈拉哈塘凹陷奥陶系原油样品庚烷值和异庚烷值分别为31.0～38.3及1.0～2.5,均值分别为36.0及2.2,据此得出样品属于高成熟油,烃源岩有机质类型为Ⅰ型和Ⅱ型。原油样品C5—C7轻烃馏分相对组成以正烷烃占优势,C7轻烃化合物相对组成以异构烷烃占优势,推测原油样品烃源岩以腐泥型有机质为主。样品Mango稳态催化轻烃参数K1值为0.97～1.07,均值为1.03,符合K1值相对稳定性规律,K2值为0.18～0.22,均值为0.20,符合海相原油特点;样品具有3RP和6RP,推测烃源岩以腐泥型有机质为主;原油生成温度为119.0～125.9℃。Based on the analyses of C5-C7 light hydrocarbons, geochemical studies including oil maturity, source rocks organic-matter types and hydrocarbon-generating temperature are carried out. The heptane and isoheptane values can be used to distinguish oils and source rock organic-matter types. These two values of the Ordovician crude oils from the Halahatang depression range from 31.0 to 38.3 and 1.0 to 2.5, with the average of 36.0 and 2.2, respectively. And according to both parameters, the samples are highly mature and the source rocks organic-matter type is type I- II. The composition characteristics of C5-C7 light hydrocarbons are usually used to determine the source rock organic-matter types. In oil samples, the C5-C7 light hydrocarbon fraction is dominated by normal alkanes,while the C7 light hydrocarbons is domi- nated by isoalkanes. It is estimated that the source rock is dominated by sapropelic organic-matter. The Mango light hydrocarbon parameters including the K1 ,K2 values and RP are widely used to estimate the source rock organic-matter types and calculate the hydrocarbon-generating temperature. The K1 values for the oil samples range from 0.97 to 1.07 with an average of 1.03 and the K2 values range from 0.18 to 0.22 with an average of 0.20. The oil samples possess 3RP and 6RP,hence,it is concluded that the source rock is dominated by sapropelic organic-matter,which is the same to the result conducted from the Cs-C7 and C7 light hydrocarbons composition characteristics. Besides, the hydrocarbon-generating temperature ranges from 119.0℃ to 125.9℃.

关 键 词：C5-C7轻烃 哈拉哈塘凹陷 庚烷值 异庚烷值 Mango稳态催化理论 

分 类 号：TE122.113[石油与天然气工程—油气勘探]