原油中部分吡咯类含氮化合物运移参数的适用性

Discussion on effects of pyrrolic nitrogen compound parameters on petroleum migration

原油中含氮化合物参数已经成为研究油气运移方向的主要手段,但大量研究实例表明,在不同的地质条件下可能取得不同的应用效果。作者根据渤海湾盆地黄骅坳陷、松辽盆地古龙凹陷、长岭凹陷和新疆焉耆盆地的部分样品,分析了油气运移过程对原油中吡咯类含氮化合物组构的影响,讨论了参数之间的相关性,初步探讨了不同参数在油气运移方向研究中的适用性。分析表明,针对部分中国陆相盆地而言,除了含氮化合物丰度和1,8-二甲基咔唑/2,7-二甲基咔唑外,比较有效的运移参数主要还有苯并[a]咔唑+苯并[b]咔唑+苯并[c]咔唑、苯并[a]咔唑/苯并[c]咔唑或苯并[a]咔唑/(苯并[a]咔唑+苯并[c]咔唑)、遮蔽型烷基咔唑化合物含量(G1)/遮蔽型烷基咔唑化合物含量(G3)、3-甲基咔唑/4-甲基咔唑、甲基咔唑/二甲基咔唑、二甲基咔唑/三甲基咔唑等。

Currently, the content and chemical composition of nitrogen compounds in crude oils are major parameters used to investigate petroleum migration directions. But a great number of research cases show that the effects of nitrogen compound parameters on petroleum migration are different in various regions under different geological and geochemical conditions. Some other factors, such as source, sedimentary (environment) and maturity, affect the content and chemical composition of nitrogen compounds, too. In this paper, the influence of petroleum migration on the chemical composition of pyrrolic nitrogen (compounds) and the relationship between the paramenters of pyrrolic nitrogen compounds are analyzed based on the data from Gulong Depression and Changlin Depression in Songliao Basin, Huanghua (Depression) in Bohaiwan Basin and Yanqi Basin. The applicability of paramenters used to estimate petroleum migration directions is introduced. The result shows that migration is the major factor impacting the distribution of pyrrole nitrogen compounds in crude oils. So is in the case of other geological and (geochemical) factors. Besides the content of nitrogen compound in crude oils and 1,8-dimethyl-carbazole/2,7-dimethyl-carbazole (1,8-DMC/2,7-DMC) used to estimate petroleum migration direction, there are some other parameters, such as benzo [a] carbazole+ benzo[b]-carbazole+ benzo[c]- carbazole ([a]+[b]+[c]), benzo[a]carbazole/benzo[c]carbazole ([a]/ [c]) or benzo[a]carbazole/ (benzo[a]carbazole +benzo[c]carbazole) ([a/([a]+[c]),G1/G3,3-methyl-carbazole/ 4-methyl- carbazole (3-MC/4-MC), methyl- carbazole/ dimethyl- carbazole (MC/DMC), dimethyl-carbazole/trimethyl-carbazole(DMC/TMC), that can be used to judge migration directions in China terrestrial formation.