鄂尔多斯盆地长7段页岩生烃活化能分布及其对页岩原位转化的启发  

Controlling factors of activation energy distribution in the Chang 7 shale and insights into in-situ conversion of shale,Ordos basin

作　　者：郑瑞辉 李志鹏 曾文人 余麒麟 满凯旋 肖伟 张枝焕[1,2] ZHENG Ruihui;LI Zhipeng;ZENG Wenren;YU Qilin;MAN Kaixuan;XIAO Wei;ZHANG Zhihuan(College of Geoscience,China University of Petroleum,Beijing 102249,China;State Key Laboratory of Petroleum Resources and Prospecting,Beijing 102249,China)

机构地区：[1]中国石油大学(北京)地球科学学院,北京102249 [2]油气资源与探测国家重点实验室,北京102249

出　　处：《地质学报》2023年第1期197-209,共13页Acta Geologica Sinica

基　　金：中国石油天然气股份有限公司与中国石油大学(北京)战略合作科技专项(编号ZLZX2020-02-01-01)资助的成果。

摘　　要：鄂尔多斯盆地三叠系延长组7段(长7段)中—低熟(R_(o)<1.0%)页岩面积占该段页岩总面积的90%左右,中—低熟页岩油/油页岩资源丰富,原位转化作为实现其工业开采的有效途径日益受到各方的关注。生烃转化率和活化能是影响页岩原位转化和开采潜力的关键因素,前人研究表明研究区长7段页岩生烃活化能分布特征存在较大的差别,但其分布规律及其控制因素尚不清楚,尤其是有机质丰度、成熟度等对页岩生烃特征和动力学过程的控制作用及其成因机制尚不明确,这必将制约研究区页岩原位转化条件和资源潜力的评价。本次研究选取了长7段成熟度相近、不同有机质丰度的5块页岩样品以及有机质丰度相近、不同成熟度的5块页岩样品,通过开放热模拟实验确定了样品的生烃动力学参数,讨论了有机质丰度和成熟度对长7段页岩动力学特征的影响。根据烃源岩生烃过程的时间-温度补偿原理,将实验室条件下获得的动力学参数外推至页岩原位转化条件下,分析了有机质丰度和成熟度对长7段页岩原位转化温度区间的影响。结果表明,在成熟度相近的情况下,受有机质中藻类体等腐泥组的富集程度影响,烃源岩的生烃活化能随有机质丰度的增大而增大;在有机质丰度相近的情况下,受有机质中富氢组分含量的影响,烃源岩的生烃活化能随有机质成熟度的增大而增大。在页岩原位转化条件下,随页岩有机质丰度和成熟度的增加,页岩原位转化对应的主要生烃期温度升高,达到主生烃期所需的加热时间增长;相近成熟度页岩样品的成烃潜力随有机质丰度的增大而增大;相近有机质丰度页岩样品的成烃潜力随有机质成熟度的增大而降低。The area of medium-to low-mature(Ro<1.0%)shale accounts for about 90%of the total shale area in the seventh member of the Yanchang Formation(Chang 7 member),Ordos basin,indicating that it is rich in medium-to low-mature shale oil/oil shale resources.In-situ conversion technology has attracted more and more attention as an effective way to realize its industrial exploitation.Hydrocarbon generation conversion rate and activation energy are the key factors affecting the in-situ conversion and exploitation potential of shale.Previous studies showed that there are great differences in the distribution characteristics of hydrocarbon generation activation energy of the Chang 7 member shale in the study area,but its distribution rule and control factors are not clear.Also,the influence of organic matter abundance and maturity on the hydrocarbon generation characteristics and dynamic process of shale and its genetic mechanism are unclear.This limits the evaluation of in-situ conversion conditions and resource potential of shale in the study area.In this study,five shale samples with similar maturity and different organic matter abundance,and five shale samples with similar organic matter abundance and different maturity were selected to determine the hydrocarbon generation kinetic parameters of the Chang 7 member shale through open thermal simulation experiment.Based on the results,the effects of organic matter abundance and maturity on the kinetic characteristics of the Chang 7 member shale are discussed.According to the time-temperature compensation principle of hydrocarbon generation process of source rocks,the kinetic parameters obtained under laboratory conditions are extrapolated to in-situ conversion conditions.The effects of organic matter abundance and maturity on the in-situ conversion temperature range of the Chang 7 member shale are analyzed.The results show that the hydrocarbon generation activation energy of source rocks increases with the increase of organic matter abundance under conditions of similar matu

关 键 词：生烃动力学 有机质丰度 成熟度 长7段页岩 页岩油原位转化 

分 类 号：P618.13[天文地球—矿床学]