江汉盆地西南缘原油中含硫化合物的分布特征及其地球化学意义  

Distribution Characteristics and Geochemical Significance of Organic Sulfur Compounds from Crude Oils in the Southwestern Jianghan Basin

作　　者：刘琼[1] 何生[2] 

机构地区：[1]中国地质大学研究生院,武汉430074 [2]中国地质大学资源学院,武汉430074

出　　处：《地质科技情报》2008年第2期56-62,共7页Geological Science and Technology Information

基　　金：中国石油化工股份有限公司中南分公司项目“江汉盆地西南缘油气运移和成藏关键期研究”(XYK-2004-01)

摘　　要：对江汉盆地西南缘12个原油样品中含硫化合物分布特征的研究表明，原油中二苯并噻吩系列化合物和苯并萘并噻吩系列化合物分别占芳烃总量的4．61％～9．79％和0．27％～1．32％，与烃源岩中含硫化合物的含量一致，反映原油中含硫化合物的含量与沉积环境有关。原油含硫化合物的内组成表明，成水环境有利于二甲基二苯并噻吩和三甲基二苯并噻吩系列化合物的相对富集。4-甲基二苯并噻吩／1-甲基二苯并噻吩峰面积比值（MDR）在低成熟阶段（R。〈0．7％）的变化范围较小，当成熟度进一步增加时，因热稳定性较差的1-甲基二苯并噻吩向其他化合物转化的速度加快，相对丰度降低，而4-甲基二苯并噻吩的相对丰度增加，致使MDR值随成熟度的增加而很快增大。同时，MDR值受到沉积条件的影响，可能指示沉积环境的成水化程度。2＋3-甲基二苯并噻吩／二苯并噻吩峰面积比值与4-甲基二苯并噻吩／二苯并噻吩峰面积比值之间表现为正相关，说明2＋3-甲基二苯并噻吩与4-甲基二苯并噻吩的形成机理相似，同样受沉积环境和成熟度的影响。This paper studies the distribution characteristics of organic sulfur compounds from twelve crude oil samples in the southwestern Jianghan Basin. The relative abundances between dibenzothiphene（DBT） and naphtha-benzothiophene（NDBT） series of total aromatic hydrocarbons are 4.61%-9.79% and 0.27% -1.32%,which are consistent to the source rocks relating to evaporite depositional environment within the lower part of Xingouzui Formation and the upper part of Shashi Formation in the study area. This saline depositional environment contributes to the relative abundance of dimethyl-and trimethyl-dibenzothiphenes in the aromatic fraction of crude oils. The relationship between C29 ββ and 4-/1-MDBT（MDR） shows that the values of 4-/1-MDBT small increase during low thermal maturity stage（Ro〈0.7%）. With increasing thermal maturity, the amount of less thermal stable 1-MDBT decreases rapidly compared with the amount of more thermal stable 4-MDBT, so the value of MDR increases quickly. This study suggests that the changes of MDR value are also affected by the depositional environment, and the MDR value may be as an indicator of the saltiness degree of sedimentary environment. The relationship of 2 ＋ 3-MDBT/ dibenzothiphene（DBT） and 4-MDBT/ DBT shows a good positive correlativity, indicating that the formation mechanism of 2 4-3-MDBT is similar to 4-MDBT , regarded to be both depositional environment and thermal maturity.

关 键 词：含硫化合物 二苯并噻吩 成熟度 沉积环境 江汉盆地西南缘 

分 类 号：TE133.1[石油与天然气工程—油气勘探]