Knowledge Management System Of Guangzhou Institute of Geochemistry，CAS
| Yan, Yu1,2,3; Wang, Min1,2; Misch, David3; Sachsenhofer, Reinhard F.3; Wu, Yan1,2; Li, Jinbu4 | |
| Mineral diagenesis in lacustrine organic-rich shales: Evolution pathways and implications for reservoir characteristics | |
| Source Publication | JOURNAL OF ASIAN EARTH SCIENCES
 |
| ISSN | 1367-9120 |
| 2024-03-15 | |
| Volume | 263Pages:23 |
| DOI | 10.1016/j.jseaes.2024.106026 |
| Language | 英语 |
| WOS Research Area | Geology |
| Abstract | Porosity in shale reservoirs is profoundly influenced by diagenetic processes that shape the evolution of pore space. In the Songliao Basin, the first member of the Qingshankou Formation (K(2)qn(1)) shale serves as a typical lacustrine clay-rich shale oil reservoir. It exhibits variable mineralogy and thermal maturity, with its reservoir quality strongly influenced by these variations. This study integrates microscopic observations, including field emission scanning electron microscopy (FE-SEM), cathodoluminescence (CL), and organic petrology, with bulk rock investigations employing X-ray diffraction (XRD), Rock-Eval pyrolysis, and elemental analysis, to reconstruct the diagenetic pathways leading to changes in porosity. The findings reveal that K(2)qn(1) shale is primarily composed of extrabasinal grain assemblages, such as detrital quartz and clay minerals, with sedimentary organic matter mainly as lamalginite. As maturity exceeds 0.8 %R-o, the presence of authigenic clay minerals, primarily characterized by chlorite, becomes widespread, often associated with bitumen impregnation. Additionally, authigenic dolomite and pyrite form during the synsedimentary to early diagenetic stages. In immature to marginally mature stages (<0.6 % R-o), mechanical compaction is the primary factor leading to porosity reduction. Pores associated with organic matter become visible when maturity reaches the oil window (>0.7 % R-o). At the peak of hydrocarbon expulsion (approximately 1.2 % R-o), a high frequency of organic matter shrinkage pores at interfaces to clay minerals is present, likely playing a significant role in enhancing permeability. Although localized occurrences of dissolution and cementation can be observed, the development of these diagenetic processes is limited and exerts minimal influence on the physical properties of the bulk rock. This study significantly contributes to our understanding of the mechanisms governing diagenetic processes and reservoir evolution in markedly heterogeneous lacustrine shale, considering the diverse origins of grain assemblages. |
| Keyword | Songliao Basin Qingshankou Formation Shale oil Clay-rich shale Organic matter porosity Diagenesis |
| WOS ID | WOS:001168551800001 |
| Indexed By | SCI |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.gig.ac.cn/handle/344008/77362 |
| Collection | 有机地球化学国家重点实验室 |
| Corresponding Author | Wang, Min |
| Affiliation | 1.China Univ Petr East China, Natl Key Lab Deep Oil & Gas, Qingdao 266580, Shandong, Peoples R China 2.China Univ Petr East China, Sch Geosci, Qingdao 266580, Peoples R China 3.Univ Leoben, Dept Appl Geosci & Geophys, Peter Tunner Str 5, A-8700 Leoben, Austria 4.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Organ Geochem, Guangzhou 510640, Guangdong, Peoples R China |
| Recommended Citation GB/T 7714 | Yan, Yu,Wang, Min,Misch, David,et al. Mineral diagenesis in lacustrine organic-rich shales: Evolution pathways and implications for reservoir characteristics[J]. JOURNAL OF ASIAN EARTH SCIENCES,2024,263:23. |
| APA | Yan, Yu,Wang, Min,Misch, David,Sachsenhofer, Reinhard F.,Wu, Yan,&Li, Jinbu.(2024).Mineral diagenesis in lacustrine organic-rich shales: Evolution pathways and implications for reservoir characteristics.JOURNAL OF ASIAN EARTH SCIENCES,263,23. |
| MLA | Yan, Yu,et al."Mineral diagenesis in lacustrine organic-rich shales: Evolution pathways and implications for reservoir characteristics".JOURNAL OF ASIAN EARTH SCIENCES 263(2024):23. |
| Files in This Item: | There are no files associated with this item. | |||||
Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.
Edit Comment