The effects of shale composition and pore structure on gas adsorption potential in highly mature marine shales, Lower Paleozoic, central Yangtze, China

2017 ◽  
Vol 54 (10) ◽  
pp. 1033-1048 ◽  
Author(s):  
Yuguang Hou ◽  
Sheng He ◽  
Nicholas B. Harris ◽  
Jizheng Yi ◽  
Yi Wang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Pore Structure ◽  
Surface Area ◽  
Sorption Capacity ◽  
Gas Adsorption ◽  
Bet Surface Area ◽  
Lower Paleozoic ◽  
Longmaxi Formation ◽  
Methane Sorption ◽  
Shale Composition

The Ordovician Wufeng Formation and Silurian Longmaxi Formation are two of the most organic-rich and gas-prospective shale formations in the central Yangtze area, China. In this study, we investigate the controls exerted by shale composition and pore structure on methane sorption of these highly matured marine shales (Ro ranges from 2.0% to 4.0%). Samples were analyzed by SEM pore imaging of Ar-ion milled samples, high pressure methane adsorption, and low temperature nitrogen adsorption. In the high TOC Wufeng and lower Longmaxi formations, numerous organic matter pores are present. A positive correlation exists between TOC, BET surface area, and CH4 sorption capacity, indicating that porosity associated with organic matter is the key factor controlling methane sorption capacity of shale samples. In the organic-lean upper Longmaxi Formation, pores within clay particles and carbonate minerals are the major pore types. Organic-lean shale samples from the upper Longmaxi Formation have higher clay content, lower BET surface area, and lower adsorption capacity than organic-rich shales. Within several low TOC samples, a relatively strong correlation exists between illite content and methane sorption capacity, which is interpreted to result from clay mineral-hosted porosity.

Probing the performance of imide linked micro-porous polymers for enhanced CO2 gas adsorption applications

2021 ◽  
Author(s):  
Narendran Rajendran ◽  
Ali A. Husain ◽  
Saad Makhseed
Keyword(s):  
Surface Area ◽  
Gas Adsorption ◽  
Oxidative Polymerization ◽  
Porous Polymers ◽  
Bet Surface Area ◽  
Co2 Gas

Three new carbazole containing cross-linked polymers namely AH-Poly, TM-PDA-Poly and TMB-PDA-Poly were designed and successfully synthesized by an oxidative polymerization protocol. The prepared AH-Poly showed a specific BET surface area...

scholarly journals Characteristics of Pore Structure and Gas Content of the Lower Paleozoic Shale from the Upper Yangtze Plate, South China

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7603
Author(s):  
Xiaoyan Zou ◽  
Xianqing Li ◽  
Jizhen Zhang ◽  
Huantong Li ◽  
Man Guo ◽  
...  
Keyword(s):  
Organic Matter ◽  
Pore Structure ◽  
Shale Gas ◽  
Lower Cambrian ◽  
Gas Content ◽  
Lower Paleozoic ◽  
Lower Silurian ◽  
Surface Areas ◽  
Specific Surface Areas ◽  
Yangtze Plate

This study is predominantly about the differences in shale pore structure and the controlling factors of shale gas content between Lower Silurian and Lower Cambrian from the upper Yangtze plate, which are of great significance to the occurrence mechanism of shale gas. The field emission scanning electron microscopy combined with Particles (Pores) and Cracks Analysis System software, CO2/N2 adsorption and the high-pressure mercury injection porosimetry, and methane adsorption were used to investigate characteristics of overall shale pore structure and organic matter pore, heterogeneity and gas content of the Lower Paleozoic in southern Sichuan Basin and northern Guizhou province from the upper Yangtze plate. Results show that porosity and the development of organic matter pores of the Lower Silurian are better than that of the Lower Cambrian, and there are four main types of pore, including interparticle pore, intraparticle pore, organic matter pore and micro-fracture. The micropores of the Lower Cambrian shale provide major pore volume and specific surface areas. In the Lower Silurian shale, there are mesopores besides micropores. Fractal dimensions representing pore structure complexity and heterogeneity gradually increase with the increase in pore volume and specific surface areas. There is a significant positive linear relationship between total organic carbon content and micropores volume and specific surface areas of the Lower Paleozoic shale, and the correlation of the Lower Silurian is more obvious than that of the Lower Cambrian. The plane porosity of organic matter increases with the increase in total organic carbon when it is less than 5%. The plane porosity of organic matter pores is positively correlated with clay minerals content and negatively correlated with brittle minerals content. The adsorption gas content of Lower Silurian and Lower Cambrian shale are 1.51–3.86 m3/t (average, 2.31 m3/t) and 0.35–2.38 m3/t (average, 1.36 m3/t). Total organic carbon, clay minerals and porosity are the main controlling factors for the differences in shale gas content between Lower Cambrian and Lower Silurian from the upper Yangtze plate. Probability entropy and organic matter plane porosity of the Lower Silurian are higher than those of Lower Cambrian shale, but form factor and roundness is smaller.

scholarly journals Petrography and Organic Geochemistry Characterizations of Lower Paleozoic Organic-Rich Shale in the Northwestern Upper Yangtze Plate: Niutitang Formation and Longmaxi Formation, Dabashan Foreland Belt

Minerals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 439 ◽  
Author(s):  
Delu Li ◽  
Rongxi Li ◽  
Di Zhao ◽  
Feng Xu
Keyword(s):  
Gas Chromatography ◽  
Organic Matter ◽  
Organic Geochemistry ◽  
Source Rocks ◽  
Gas Chromatography Mass Spectrometry ◽  
Mature Stage ◽  
Type I ◽  
Lower Paleozoic ◽  
Longmaxi Formation ◽  
Niutitang Formation

Measurements of total organic carbon, Rock-Eval pyrolysis, X-ray diffraction, scanning electron microscope, maceral examination, gas chromatography, and gas chromatography-mass spectrometry were conducted on the organic-rich shale of Lower Paleozoic Niutitang Formation and Longmaxi Formation in Dabashan foreland belt to discuss the organic matter characteristic, organic matter origin, redox condition, and salinity. The results indicate that the Niutiang Formation and Longmaxi Formation organic-rich shale are good and very good source rocks with Type I kerogen. Both of the shales have reached mature stage for generating gas. Biomarker analyses indicate that the organic matter origin of Niutitang Formation and Longmaxi Formation organic-rich shale are all derived from the lower bacteria and algae, and the organic matter are all suffered different biodegradation degrees. During Niutitang Formation and Longmaxi Formation period, the redox conditions are both anoxic with no stratification and the sedimentary water is normal marine water.

The whole-aperture pore-structure characteristics of marine-continental transitional shale facies of the Taiyuan and Shanxi Formations in the Qinshui Basin, North China

2019 ◽  
Vol 7 (2) ◽  
pp. T547-T563 ◽  
Author(s):  
Jiyuan Wang ◽  
Shaobin Guo
Keyword(s):  
High Pressure ◽  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
Gas Adsorption ◽  
Pore Morphology ◽  
Qinshui Basin ◽  
Mercury Intrusion ◽  
Structure Characteristics

To systematically study the whole-aperture pore-structure characteristics of the marine-continental transitional shale facies in the Upper Palaeozoic Taiyuan and Shanxi Formations of the Qinshui Basin, we have collected a total of 11 samples for high-pressure mercury intrusion, low-pressure gas adsorption ([Formula: see text] and [Formula: see text]), nuclear magnetic resonance (NMR), and field-emission scanning electron microscopy with argon-ion polishing experiments to determine the pore morphology and distribution characteristics of shale samples in detail and to perform quantitative analyses. Then compared the pore-development characteristics of the Taiyuan Formation samples with those of the Shanxi Formation to determine which is preferable. The experimental results indicate that the shale samples of the Qinshui Basin mainly develop three types of pores: organic pores, intergranular pores, and microfractures. High-pressure mercury intrusion and gas-adsorption experiments indicate that the pore-size distributions exhibit multiple peaks. The samples contained varying proportions of macropores, mesopores, and micropores, among which the former two are dominant, accounting for approximately 85% of the total pore volume, whereas micropores account for only 15%. However, mesopores and micropores dominate the specific surface area; between them, the micropores are much more prevalent, accounting for more than 99% of the total specific surface area. Macropores contribute less than 1% of the specific surface area and therefore can be neglected. The pore morphology resembles the slit type parallel platy pores with a ballpoint pen structure. The NMR [Formula: see text] spectra have multiple-peak values. In addition, the large difference between the curved areas before and after centrifugation indicates that the samples contain a large proportion of mesopores and macropores, which is consistent with the results presented above. The results demonstrate that the development of pores in the Taiyuan Formation is better than that in the Shanxi Formation.

scholarly journals Quantitative Characterization for the Micronanopore Structures of Terrestrial Shales with Different Lithofacies Types: A Case Study of the Jurassic Lianggaoshan Formation in the Southeastern Sichuan Basin of the Yangtze Region

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Weiwei Liu ◽  
Kun Zhang ◽  
Qianwen Li ◽  
Zhanhai Yu ◽  
Sihong Cheng ◽  
...  
Keyword(s):  
Organic Matter ◽  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Sichuan Basin ◽  
Parallel Plate ◽  
Quantitative Characterization ◽  
Southeastern Sichuan Basin

Due to the specificity of the geological background, terrestrial strata are widely distributed in the major hydrocarbon-bearing basins in China. In addition, terrestrial shales are generally featured with high thickness, multiple layers, high TOC content, ideal organic matter types, and moderate thermal evolution, laying a solid material foundation for hydrocarbon generation. However, the quantitative characterization study on their pore structure remains inadequate. In this study, core samples were selected from the Middle Jurassic Lianggaoshan Formation in the southeastern Sichuan Basin of the Upper Yangtze Region for analyses on its TOC content and mineral composition. Besides, experiments including oil washing, the adsorption/desorption of CO2 and nitrogen, and high-pressure mercury pressure experiments were carried out. The pore structure of different petrographic types of terrestrial shales can be accurately and quantitatively characterized with these works. The following conclusions were drawn: for organic-rich mixed shales and organic-rich clay shales, the TOC content is the highest; the pore volume, which is primarily provided by macropores and specific surface area, which is provided by mesopores, was the largest, thus providing more space for shale oil and gas reservation. The pores take on a shape either close to a parallel plate slit or close to or of an ink bottle. For organic-matter-bearing shales, both the pore volume and specific surface area are the second-largest and are provided by the same sized pores with organic-rich mixed shales. Its pores take on a shape approximating either a parallel plate slit or an ink bottle. Organic-matter-bearing mixed shales have the lowest pore volume and specific surface area; its pore volume is primarily provided by macropores, and the specific surface area by mesopores and the shape of the pores are close to an ink bottle.

scholarly journals Other Properties (BET Surface Area, Conductivity, Organic Matter, and pH)

2021 ◽  
pp. 197-204
Author(s):  
Modi Ahmed ◽  
Khaliq Beg
Keyword(s):  
Electrical Conductivity ◽  
Organic Matter ◽  
Surface Area ◽  
Organic Matter Content ◽  
Mineralogical Composition ◽  
Electrical Current ◽  
Matter Content ◽  
Dust Particles ◽  
Bet Surface Area ◽  
List Type

Abstract Brunauer, Emmett, and Teller (BET) test were applied to dust samples in which samples (BET) surface area is highly related to the roundness of dust particles. The higher angularity and low roundness of the dust particles show a higher (BET) surface area. The roundness is also related to the particlesize distribution and mineralogical composition. The electrical conductivity test relates very well with the chemical and physical properties of dust samples in the transmission of an electrical current. The organic matter content was measured using the ignition method and the pH of the samples was recorded. Maps of the distribution of high and low BET concentrations, electrical conductivity EC, organic matter content, pH.

scholarly journals Relationship between Organic Geochemistry and Reservoir Characteristics of the Wufeng-Longmaxi Formation Shale in Southeastern Chongqing, SW China

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6716
Author(s):  
Shengxiu Wang ◽  
Jia Wang ◽  
Yuelei Zhang ◽  
Dahua Li ◽  
Weiwei Jiao ◽  
...  
Keyword(s):  
Organic Matter ◽  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Clay Mineral ◽  
Shale Gas ◽  
Mineral Content ◽  
Organic Geochemistry ◽  
Quartz Content ◽  
Longmaxi Formation

Shale gas accumulates in reservoirs that have favorable characteristics and associated organic geochemistry. The Wufeng-Longmaxi formation of Well Yucan-6 in Southeast Chongqing, SW China was used as a representative example to analyze the organic geochemical and reservoir characteristics of various shale intervals. Total organic carbon (TOC), vitrinite reflectance (Ro), rock pyrolysis, scanning electron microscopy (SEM), and nitrogen adsorption analyses were conducted, and a vertical coupling variation law was established. Results showed the following: the Wufeng-Longmaxi formation shale contains kerogen types I and II2; the average TOC value at the bottom of the formation is 3.04% (and the average value overall is 0.78%); the average Ro value is 1.94%; the organic matter is in a post mature thermal evolutionary stage; the shale minerals are mainly quartz and clay; and the pores are mainly intergranular, intragranular dissolved pores, organic matter pores and micro fractures. In addition, the average specific surface area (BET) of the shale is 5.171 m2/g; micropores account for 4.46% of the total volume; the specific surface area reaches 14.6%; and mesopores and macropores are the main pore spaces. There is a positive correlation between TOC and the quartz content of Wufeng-Longmaxi shale, and porosity is positively correlated with the clay mineral content. It is known that organic pores and the specific area develop more favorably when the clay mineral content is higher because the adsorption capacity is enhanced. In addition, as shale with a high clay mineral content and high TOC content promotes the formation of a large number of nanopores, it has a strong adsorption capacity. Therefore, the most favorable interval for shale gas exploration and development in this well is the shale that has a high TOC content, high clay mineral content, and a suitable quartz content. The findings of this study can help to better identify shale reservoirs and predict the sweet point in shale gas exploration and development.

scholarly journals Pore Structure and Fractal Characteristics of Organic-Rich Lacustrine Shales of the Kongdian Formation, Cangdong Sag, Bohai Bay Basin

2021 ◽  
Vol 9 ◽  
Author(s):  
Shouxu Pan ◽  
Ming Zha ◽  
Changhai Gao ◽  
Jiangxiu Qu ◽  
Xiujian Ding
Keyword(s):  
Organic Matter ◽  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Clay Minerals ◽  
Mineral Composition ◽  
Fractal Dimensions ◽  
Nitrogen Adsorption ◽  
Thermal Maturity ◽  
Pore Types

In order to examine the pore structure and reveal the fractal geometric nature of shales, a series of laboratory experiments were conducted on lacustrine shale samples cored from the Kongdian Formation. Based on the low temperature nitrogen adsorption, fluorescent thin section and field emission scanning electronic microscope, a comprehensive pore structure classification and evaluation were conducted on shale samples. Fractal dimensions D1 and D2 (with relative pressure of 0–0.45 and 0.45–1.00, respectively) were obtained from the nitrogen adsorption data using the fractal Frenkel-Halsey-Hill (FHH) method. With additional means of X-ray diffraction analysis, total organic carbon content analysis and thermal maturity analysis, the relationships between pore structure parameters, fractal dimensions, TOC content and mineral composition are presented and discussed in this paper. The results show that interparticle pores and microfractures are predominant, whereas organic matter pores are rarely found. The pore morphology is primarily featured with wide-open ends and slit-shaped structures. In terms of pore scale, mesopores and macropores are predominant. The value of fractal dimension D1 representing small pores ranges from 2.0173 to 2.4642 with an average of 2.1735. The value of D2 which represents large pores ranges from 2.3616 to 2.5981 with an average of 2.4960. These low numbers are an indication of few pore types and relatively low heterogeneity. In addition, smaller D1 values reveal that large pores have more complicated spatial structures than smaller ones. The results of correlation analysis show that: 1) D2 is correlated positively with specific surface area but negatively with average pore diameter; 2) D1 and D2 literally show no obvious relationship with mineral composition, TOC content or vitrinite reflectance (Ro); 3) both total Barrett-Joyner-Halenda (BJH) volume and specific surface area show a positive relationship with dolomite content and a negative relationship with felsic minerals content. These results demonstrate that the pore types are relatively few and dominated by mesopores, and the content of brittle minerals such as dolomite and felsic minerals control the pore structure development whilst organic matter and clay minerals have less influence due to low thermal maturity and abundance of clay minerals.

Effects of extraction process on the dried cell wall pore structure of messmate heartwood

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 6074-6082
Author(s):  
Weikai Wang ◽  
Minghan Li ◽  
Jiabin Cai
Keyword(s):  
Cell Wall ◽  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Gas Adsorption ◽  
Extraction Process ◽  
Micropore Volume ◽  
Adsorption Method

In order to study the effects of a messmate heartwood extraction process on its cell wall pore structure and its drying ability, its nanopore structure was explored after via gas adsorption technology. Specifically, the messmate heartwood particles were extracted with methanol, and then the cell wall pore structure of the original and extracted samples were evaluated by N2 and CO2 sorption and pycnometer methods, respectively. Overall, compared with the original samples, the cell wall porosity, micropore volume, mesopore volume, BET specific surface area, and specific surface area of the micropores of the extracted messmate heartwoods increased by 2.55%, 0.007 cm3/g, 0.0014 cm3/g, 0.24 m2·g-1, and 21.9 m2·g-1, respectively. The cell wall pore volume measured via the gas adsorption method was smaller than the measurement from the pycnometer method. The results indicated that the presence of extractives made the messmate cell wall have a decreased pore volume and porosity, which may be one of the reasons messmate wood is difficult to dry. Messmate extractives primarily were present in the micropores of the cell wall in the range of 0.4 nm to 0.7 nm. However, gas sorption technology could not detect all the pores in the cell wall of the messmate heartwood sample.

Sign in / Sign up

Export Citation Format

Share Document