柴达木盆地咸化湖盆低有机质丰度烃源岩高效生烃模式  

Low organic matter abundance and highly efficient hydrocarbon generation of saline source rock in the Qaidam Basin,NW China

作　　者：李国欣 张斌[3] 伍坤宇[4] 吴松涛[3] 王晓梅[3] 张静 齐雪宁 张娜 邢浩婷 鲜成钢 刘合[3] LI Guoxin;ZHANG Bin;WU Kunyu;WU Songtao;WANG Xiaomei;ZHANG Jing;QI Xuening;ZHANG Na;XING Haoting;XIAN Chenggang;LIU He(State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum,Beijing 102249,China;China National Petroleum Corporation,Beijing 100007,China;Research Institute of Petroleum Exploration&Development,PetroChina,Beijing 100083,China;PetroChina Qinghai Oilfield Company,Dunhuang 736202,China)

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [2]中国石油天然气集团有限公司,北京100007 [3]中国石油勘探开发研究院,北京100083 [4]中国石油青海油田公司勘探开发研究院,甘肃敦煌736202

出　　处：《石油勘探与开发》2023年第5期898-910,共13页Petroleum Exploration and Development

基　　金：中国石油天然气股份有限公司科学研究与技术研发项目(2021DJ1808)。

摘　　要：通过实验模拟和地球化学分析,系统研究柴达木盆地柴西坳陷古近系烃源岩的生烃母质、有机质富集与生烃模式。柴达木咸化湖盆烃源岩总有机碳含量(TOC)值偏低的原因主要有3方面:相对贫乏的营养物质供应抑制了藻类勃发、过快的沉积速率导致有机质被稀释、较高的有机质转化效率导致残留有机碳偏低。针对这类富氢有机质生烃过程中有机碳降低,应用TOC值评价有机质丰度时需根据成熟度对其进行恢复。柴达木盆地咸化湖盆烃源岩生烃包括可溶有机质生烃和不溶有机质生烃两部分。可溶有机质主要继承于生物体在咸化湖盆中得以保存,在低演化阶段生烃形成的烃富含氮、氧、硫等杂原子化合物,在后期二次裂解形成轻质烃类组分;不溶有机质即干酪根生烃模式符合传统的“Tissot”模式,生油高峰对应于Ro值1.0%左右。The geochemical analysis and experimental simulation are comprehensively used to systematically study the hydrocarbon generation parent material,organic matter enrichment and hydrocarbon generation model of Paleogene source rock in the Western Qaidam Depression,Qaidam Basin,NW China.Three main factors result in low TOC values of source rock in the saline lake basin of the Qaidam Basin:relatively poor nutrient supply inhibits the algal bloom,too fast deposition rate causes the dilution of organic matter,and high organic matter conversion efficiency causes the low residual organic carbon.For this type of hydrogen-rich organic matter,due to the reduction of organic carbon during hydrocarbon generation,TOC needs to be restored based on maturity before evaluating organic matter abundance.The hydrocarbon generation of source rocks in the saline lake basin of the Qaidam Basin is from two parts:soluble organic matter and insoluble organic matter.The soluble organic matter is inherited from organisms and preserved in saline lake basins.It generates hydrocarbons during low-maturity evolution stages,and the formed hydrocarbons are rich in complex compounds such as NOS,and undergo secondary cracking to form light components in the later stage;the hydrocarbon generation model of insoluble organic matter conforms to the traditional“Tissot”model,with an oil generation peak corresponding to Ro of 1.0%.

关 键 词：柴达木盆地 柴西坳陷 古近系下干柴沟组 咸化湖盆 低TOC 页岩油 可溶有机质 高效生烃 生烃模式 有机质丰度 

分 类 号：TE122.2[石油与天然气工程—油气勘探]