土库曼斯坦图兰台坪南部地区油田原油芳烃地球化学特征

Geochemical characteristics of aromatic hydrocarbons of oilfields in the southern Turantaping of Turkmenistan

通过对图兰台坪南部地区6个不同油田原油抽提物芳烃色谱-质谱分析与研究,发现各油田原油芳烃化合物组成均具有高萘、高菲、高硫芴的特征,沉积环境整体上处于还原—强还原环境。K油田、T油田与S油田三芴系列化合物分布集中,原油生油母质类型相近;而Y油田、G油田及D油田原油样品分布偏离集群区,且均含较高的联苯系列化合物,表明原油的生源有机质偏腐殖型。选取烷基萘,三芳甾烷、甲基菲及烷基二苯并噻吩四类不同构型参数综合对比研究原油成熟度特征,除三芳甾类化合物成熟度参数差异较小以外,其他三类参数均可以反映出Y油田和G油田原油成熟度最高,S油田原油成熟度次之,K油田及T油田原油成熟度最低的特征。应用前人提出的相关图版及经验公式定量分析原油成熟度,仅烷基二苯并噻吩及烷基萘成熟度参数表明原油等效镜质体反射率为1.09%~1.35%,其他参数计算的成熟度值明显偏低。

Through the analysis and study of aromatics chromatography-mass spectrometry of crude oil extracts from 6 different oilfields in the southern region of Turantaping,it is found that the composition of aromatics compounds in each oilfield has the characteristics of high naphthalene,high phenanthrene,and high sulfur fluorene,and the sedimentary environment is in the overall reducing-strong reducing environment.The distribution of trifluorene series compounds in the K,T,and S Oilfields is concentrated,and the type of crude oil source material is similar.The distribution of crude oil samples from the Y,G,and D Oilfields deviated from the cluster area,and all of them has higher biphenyl series compounds,indicating that the source organic matter of crude oil is a partial humic type.Four different configuration parameters of alkyl naphthalene,triarylsterane,methylphenanthrene,and alkyl dibenzothiophene are selected to comprehensively compare the maturity characteristics of crude oil.Except for triarylsteroidal maturity parameters,the other three parameters can reflect the highest maturity of crude oils in the Y and G Oilfields,followed by that in the S Oilfield,and the lowest maturity of crude oils in K and T Oilfields.The crude oil maturity was quantitatively analyzed by using the correlation chart and empirical formula proposed by previous authors.Only the maturity parameters of alkyl dibenzothiophene and alkyl naphthalene shows that the equivalent vitrinite reflectance of crude oil is from 1.09%to 1.35%,and the maturity values calculated by other parameters are significantly low.