松辽盆地古龙页岩油储层干酪根的有机元素组成及其N元素的地球化学意义  

Organic element compositions and its N geochemical significances of the kerogen of Gulong shale oil reservoir in Songliao basin

作　　者：何文渊 白雪峰 钟建华 赵莹[2] 孙宁亮 HE Wenyuan;BAI Xuefeng;ZHONG Jianhua;ZHAO Ying;SUN Ningliang(China National Oil and Gas Exploration and Development Company Ltd.(CNODC),Beijing 100032,China;National Key Laboratory of Green Exploitation of Continental Shale Oil with Multi-Resource Collaboration,Daqing,Heilongjiang 163002,China;School of Resources&Materials,Northeastern University at Qinghuangdao,Qinghuangdao,Hebei 066004,China;National Engineering Research Center of Offshore Oil and Gas Exploration,Beijing 100028,China;School of Geosciences,China University of Petroleum(Eastern China),Qingdao,Shandong 266580,China;Institute of Ocean Engineering,Northeastern University at Qinhuangdao,Qinhuangdao,Hebei 066004,China)

机构地区：[1]中国石油国际勘探开发有限公司,北京100032 [2]多资源协同陆相页岩油绿色开采全国重点实验室,黑龙江大庆163002 [3]东北大学秦皇岛分校资源与材料学院,河北秦皇岛066004 [4]海洋油气勘探国家工程研究中心,北京100028 [5]中国石油大学(华东)地球科学与技术学院,山东青岛266580 [6]东北大学海洋工程研究院,河北秦皇岛066004

出　　处：《地质学报》2024年第6期1840-1866,共27页Acta Geologica Sinica

基　　金：国家自然科学基金项目(编号42072138,41572088);中国石油天然气股份有限公司重大科技专项(编号2021ZZ10);黑龙江省“百千万”工程科技重大专项(编号2020ZX05A01)联合资助的成果。

摘　　要：对青山口组页岩的317件干酪根样品进行了工业、元素及能谱分析,对样品进行两次校正,引入合理评价干酪根C、H、O、N的指标C_(cc)、H_(cc)、O_(cc)、N_(cc)概念。研究结果显示:古龙凹陷青山口组泥页岩Ⅰ型干酪根具有较高的H_(cc)、N_(cc)和很低的O_(cc),而Ⅲ型干酪根的O_(cc)则较高,H_(cc)、N_(cc)较低。Ⅱ干酪根的H_(cc)和N_(cc)低于Ⅰ型干酪根,而高于Ⅲ型干酪根;Ⅱ干酪根的O_(cc)高于Ⅰ型和Ⅲ型干酪根。N_(cc)主要以有机官能团(NH3+)方式存在的于黏土的F-F纳缝中,而不是存在于黏土晶胞间的无机N(NH4)。微量元素研究表明,古龙青山口组页岩油储层沉积时经历了十几次干旱咸水环境,因为咸水环境有利于形成黏土的F-F凝聚,使发育有NH3+官能团的有机质被吸附在黏土片的F-F纳缝之间。随着深度的增加,N_(cc)的克分子量增加速率是C_(cc)克分子量增加速率的0.96~2.04倍,在青山口组1300~2550m深度内青一段干酪根的N_(cc)含量明显比上部的干酪根相对高,主要原因与下部青一段藻类较富集有关,其次与H_(cc)的快速脱落而使N_(cc)相对富集有关,间接地揭示了青一段生烃能力较上部强。通过研究N_(cc)可以间接地知道古环境中的咸度、黏土的孔隙类型及其干酪根的来源。经过论证,O_(cc)和N_(cc)越大,页岩的封存性也就越好,含油气性也越好。因此,O_(cc)和N_(cc)值可以作为判别页岩油发育程度的指标。古龙页岩油储层的N_(cc)和O_(cc)的研究可以提供一些重要的沉积环境、地球化学、黏土结构、干酪根有机质类型和成岩成储及成藏等信息,应该受到重视。The present study conducted industrial analysis,elemental analysis,and energy spectrum analysis on 317 kerogen samples from the shale of the Qingshankou Formation.The samples underwent two calibrations,and the concepts of C_(cc),H_(cc),O_(cc),and N_(cc) were introduced to effectively evaluate the C,H,O,and N content in the kerogen.The results showed that type-I kerogen exhibited higher H_(cc) and N_(cc) values,while having lower O_(cc) values.In contrast,type-III kerogen displayed higher O_(cc) values and lower H_(cc) and N_(cc) values in the Qingshankou Formation shale in the Gulong sag area.Kerogen II had lower H_(cc) and N_(cc) values than type-I kerogen but higher values than type-III kerogen.Additionally,the O_(cc) value of kerogen II was higher compared to that of type-I and type-III kerogen.N_(cc) primarily exists in the F-F nanocrystals of clay in the form of organic functional groups(NH3+),rather than in the inorganic N(NH4)between clay cells.Trace element analysis indicated that the shale oil reservoir of the Gulong Qingshankou Formation experienced multiple arid and saltine water environments during deposition.The presence of a saltine water environment facilitated the formation of F-F condensation of clay,leading to the adsorption of organic matter with NH3+functional groups between the F-F nanocracks of the clay sheet.With increasing depth,the rate of increase in the molecular weight of N_(cc) was observed to be 0.96 to 2.04 times higher than that of C_(cc).Notably,the N_(cc) content of kerogen in the lower section of the Qingshankou Formation at depths ranging from 1300 to 2550 m is significantly higher than that in the upper section.This difference can be attributed to the enrichment of algae in the lower section of the Qingshankou Formation and the relatively higher enrichment of N_(cc) due to the rapid release of H_(cc).This indirectly suggests a stronger hydrocarbon generation capacity in the Qingyi area compared to the upper section.The study of N_(cc) provides valuable insight into the paleoen

关 键 词：黏土 干酪根 有机元素 N 页岩油 古龙凹陷 

分 类 号：P618.13[天文地球—矿床学]