生物地层格架下湘西北地区五峰组—龙马溪组孔隙结构特征  

Pore Structural Characteristics of Wufeng-Longmaxi Formations Under Biostratigraphic Framework in Northwestern Hunan

作　　者：漆洋 吕春研 王宇慧 唐书恒[1,2,3] 郗兆栋 QI Yang;Lü Chunyan;WANG Yuhui;TANG Shuheng;XI Zhaodong(School of Energy Resources,China University of Geosciences,Beijing 100083,China;Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Enrichment Mechanism,Ministry of Education,Beijing 100083,China;Beijing Key Laboratory of Unconventional Natural Gas Geological Evaluation and Development Engineering,Beijing 100083,China)

机构地区：[1]中国地质大学(北京)能源学院,北京100083 [2]海相储层演化与油气富集机理教育部重点实验室,北京100083 [3]非常规天然气地质评价与开发工程北京市重点实验室,北京100083

出　　处：《现代地质》2022年第5期1292-1303,共12页Geoscience

基　　金：国家科技重大专项“四川盆地及周缘页岩气富集规律与重点目标评价”(2017ZX05035)。

摘　　要：为探究生物地层格架下五峰组—龙马溪组孔隙结构特征,在笔石带划分的基础上结合孔隙结构特征及其影响因素将SY-3井五峰组—龙马溪组划分为LM5—LM7、WF4—LM4、WF2—WF3三个笔石带,并基于扫描电镜、低温氮气吸附实验、高压压汞实验等技术手段,分别对这三个笔石带进行孔隙结构特征的研究和对比。结果表明:LM5—LM7富集黏土矿物,主要发育较大孔径孔隙,以黏土矿物粒间孔为主;WF4—LM4富集有机质,主要发育较小孔径孔隙,以有机质孔为主;WF2—WF3富集石英,主要发育小孔径孔隙,以石英粒间孔为主,但大部分石英粒间孔被黏土矿物和有机质充填。LM5—LM7孔隙发育主要受TOC含量和矿物含量的影响,WF4—LM4孔隙发育主要受TOC含量影响,而WF2—WF3受矿物组分、有机质赋存特征及成岩作用等因素共同影响。不同笔石带由于沉积环境的差异导致其具有不同的有机质丰度及矿物组分,从而导致了孔隙结构的差异。To explore the pore structural characteristics of Wufeng-Longmaxi formations under the biostratigraphic framework,these formations in well SY-3 are divided into LM5-LM7,WF4-LM4 and WF2-WF3,based on the pore structural characteristics and influencing factors.The pore structural characteristics of these three graptolite zones are studied and compared by means of scanning electron microscope,low-temperature nitrogen adsorption,and high-pressure mercury injection experiment.The results show that LM5-LM7 is rich in clay minerals and develops mainly macropores(intergranular pores formed by clay minerals).WF4-LM4 is rich in organic matter and develops mainly micropores(organic pores).WF2-WF3 is rich in quartz and develops mainly micropores(intergranular pores formed by quartz).Most of the intergranular pores are filled with clay minerals and organic matter.TOC and mineral contents are the main influence factors of pore development in the LM5-LM7.TOC content is the main influence factor of pore development in the WF4-LM4,and the WF2-WF3 is affected by mineral constituent,organic matter occurrence and diagenesis.Different graptolite zones have different organic matter abundance and mineral constituents due to the different sedimentary environments,which leads to the pore structural difference.

关 键 词：生物地层 五峰组—龙马溪组 孔隙结构 低温氮气吸附实验 高压压汞实验 

分 类 号：P618.1[天文地球—矿床学] TE122.2[天文地球—地质学]