Pore Fractal Characteristics of Lacustrine Shale of Upper Cretaceous Nenjiang Formation from the Songliao Basin, NE China
The evaluation of pore characteristics in lacustrine shales is of significance for shale oil and gas exploration in terrestrial sedimentary basins. However, due to the complex depositional environments, there have been few reports on the quantitative evaluation of lacustrine pores. In this study, we...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-03-01
|
| Series: | Applied Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2076-3417/13/7/4295 |
| _version_ | 1797608315987951616 |
|---|---|
| author | Tian Dong Lei Kang Yifan Zhang Yuan Gao |
| author_facet | Tian Dong Lei Kang Yifan Zhang Yuan Gao |
| author_sort | Tian Dong |
| collection | DOAJ |
| description | The evaluation of pore characteristics in lacustrine shales is of significance for shale oil and gas exploration in terrestrial sedimentary basins. However, due to the complex depositional environments, there have been few reports on the quantitative evaluation of lacustrine pores. In this study, we carry out experiments, e.g., scanning electron microscopy (SEM), nitrogen adsorption, X-ray diffraction (XRD), and rock pyrolysis, on sixteen lacustrine shale core samples of the Late Cretaceous Nenjiang Formation (K<sub>2</sub>n<sup>1+2</sup>) in the Songliao Basin. At the same time, we bring in the fractal dimensions to quantitatively characterize the pores of shale samples in K<sub>2</sub>n<sup>1+2</sup>. The kerogen type of shales in the Nenjiang Formation is mainly type Ⅰ. The shales of K<sub>2</sub>n<sup>1+2</sup> develop a large number of mineral intergranular pores and a small number of organic pores and mineral intragranular pores. The primary minerals of the samples are clay minerals and quartz. The total organic carbon (TOC) has a correlation with the pore physical parameters, whereas the content of minerals does not correlate significantly with pore development. The average pore fractal dimensions obtained from the analysis of nitrogen adsorption data are D1 = 2.5308 and D2 = 2.6557. There is a significant negative correlation between the fractal dimensions (D1 and D2) and the TOC content: the lower the fractal dimensions, the higher the TOC, and the more the free oil. In low maturity shales with higher TOC content, due to hydrocarbon generation, larger pores with a regular shape (small fractal parameters) can be produced, which can store more free oil. The shale reservoir evaluation of K<sub>2</sub>n<sup>1+2</sup> in the Songliao Basin should be focused on shales with higher TOC and lower pore fractal parameters. Our work provides a reference for the shale oil evaluation of K<sub>2</sub>n<sup>1+2</sup> in the Songliao Basin and complements studies on lacustrine pore characteristics. |
| first_indexed | 2024-03-11T05:42:45Z |
| format | Article |
| id | doaj.art-49331ba8b39e481d841b3e266960b71b |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-11T05:42:45Z |
| publishDate | 2023-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-49331ba8b39e481d841b3e266960b71b2023-11-17T16:18:22ZengMDPI AGApplied Sciences2076-34172023-03-01137429510.3390/app13074295Pore Fractal Characteristics of Lacustrine Shale of Upper Cretaceous Nenjiang Formation from the Songliao Basin, NE ChinaTian Dong0Lei Kang1Yifan Zhang2Yuan Gao3School of Earth Science and Resources, China University of Geosciences (Beijing), Beijing 100083, ChinaCollege of Mechanical and Electronic Engineering, Dalian Minzu University, Dalian 116600, ChinaSchool of Earth Science and Resources, China University of Geosciences (Beijing), Beijing 100083, ChinaSchool of Earth Science and Resources, China University of Geosciences (Beijing), Beijing 100083, ChinaThe evaluation of pore characteristics in lacustrine shales is of significance for shale oil and gas exploration in terrestrial sedimentary basins. However, due to the complex depositional environments, there have been few reports on the quantitative evaluation of lacustrine pores. In this study, we carry out experiments, e.g., scanning electron microscopy (SEM), nitrogen adsorption, X-ray diffraction (XRD), and rock pyrolysis, on sixteen lacustrine shale core samples of the Late Cretaceous Nenjiang Formation (K<sub>2</sub>n<sup>1+2</sup>) in the Songliao Basin. At the same time, we bring in the fractal dimensions to quantitatively characterize the pores of shale samples in K<sub>2</sub>n<sup>1+2</sup>. The kerogen type of shales in the Nenjiang Formation is mainly type Ⅰ. The shales of K<sub>2</sub>n<sup>1+2</sup> develop a large number of mineral intergranular pores and a small number of organic pores and mineral intragranular pores. The primary minerals of the samples are clay minerals and quartz. The total organic carbon (TOC) has a correlation with the pore physical parameters, whereas the content of minerals does not correlate significantly with pore development. The average pore fractal dimensions obtained from the analysis of nitrogen adsorption data are D1 = 2.5308 and D2 = 2.6557. There is a significant negative correlation between the fractal dimensions (D1 and D2) and the TOC content: the lower the fractal dimensions, the higher the TOC, and the more the free oil. In low maturity shales with higher TOC content, due to hydrocarbon generation, larger pores with a regular shape (small fractal parameters) can be produced, which can store more free oil. The shale reservoir evaluation of K<sub>2</sub>n<sup>1+2</sup> in the Songliao Basin should be focused on shales with higher TOC and lower pore fractal parameters. Our work provides a reference for the shale oil evaluation of K<sub>2</sub>n<sup>1+2</sup> in the Songliao Basin and complements studies on lacustrine pore characteristics.https://www.mdpi.com/2076-3417/13/7/4295shale oilpore structurefractal dimensionlacustrineSongliao Basin |
| spellingShingle | Tian Dong Lei Kang Yifan Zhang Yuan Gao Pore Fractal Characteristics of Lacustrine Shale of Upper Cretaceous Nenjiang Formation from the Songliao Basin, NE China Applied Sciences shale oil pore structure fractal dimension lacustrine Songliao Basin |
| title | Pore Fractal Characteristics of Lacustrine Shale of Upper Cretaceous Nenjiang Formation from the Songliao Basin, NE China |
| title_full | Pore Fractal Characteristics of Lacustrine Shale of Upper Cretaceous Nenjiang Formation from the Songliao Basin, NE China |
| title_fullStr | Pore Fractal Characteristics of Lacustrine Shale of Upper Cretaceous Nenjiang Formation from the Songliao Basin, NE China |
| title_full_unstemmed | Pore Fractal Characteristics of Lacustrine Shale of Upper Cretaceous Nenjiang Formation from the Songliao Basin, NE China |
| title_short | Pore Fractal Characteristics of Lacustrine Shale of Upper Cretaceous Nenjiang Formation from the Songliao Basin, NE China |
| title_sort | pore fractal characteristics of lacustrine shale of upper cretaceous nenjiang formation from the songliao basin ne china |
| topic | shale oil pore structure fractal dimension lacustrine Songliao Basin |
| url | https://www.mdpi.com/2076-3417/13/7/4295 |
| work_keys_str_mv | AT tiandong porefractalcharacteristicsoflacustrineshaleofuppercretaceousnenjiangformationfromthesongliaobasinnechina AT leikang porefractalcharacteristicsoflacustrineshaleofuppercretaceousnenjiangformationfromthesongliaobasinnechina AT yifanzhang porefractalcharacteristicsoflacustrineshaleofuppercretaceousnenjiangformationfromthesongliaobasinnechina AT yuangao porefractalcharacteristicsoflacustrineshaleofuppercretaceousnenjiangformationfromthesongliaobasinnechina |