scholarly journals Quantitative Characterization of Organic Pore Structure from Gas Adsorption in Lower Cretaceous Lacustrine Shales in the Songliao Basin, NE China

Lithosphere ◽  
2021 ◽  
Vol 2021 (Special 1) ◽  
Author(s):  
Fenglin Gao ◽  
Chengxi Wang ◽  
Yan Song ◽  
Chengxiang Wan ◽  
Fengyang Xiong ◽  
...  
Keyword(s):  
Pore Structure ◽  
Lower Cretaceous ◽  
Gas Adsorption ◽  
Optical Microscope ◽  
Songliao Basin ◽  
Average Pore ◽  
Obvious Effect ◽  
Gas Molecules ◽  
Organic Pv

Abstract Organic matter (OM) pores are widely considered to be important for gas storage and transportation. In this work, we quantitatively analyze the pore structure of OM and its controlling factors through geochemical and petrologic analyses, optical microscope, OM isolation, and adsorption isotherms. These analyses were carried out on lacustrine shale samples from the Lower Cretaceous Shahezi Formation, which is located in the Changling Fault Depression in Songliao Basin. The results show that the content of soluble OM (SOM) is low, accounting for 0.26%-3.75% of total OM. The contribution of pore development from SOM itself is limited. After extraction of SOM by chloroform, pore volume (PV), specific surface area (SSA), and average pore diameter (APD) exposed to gas molecules greatly increase. The existence of SOM has an obvious effect on pores of >10 nm, especially the clay mineral-related pores that contribute the most to the total PV. The content of kerogen is higher than SOM and accounts for 9.9%-65.5% (averaging 24.0%) of total PV in bulk shale, only second to minerals. More importantly, kerogen is the dominant contributor to organic PV, accounting for 95.8%-99.7% (averaging 98.3%) of the total organic PV. The pores developed in the kerogen peak at 0.4-0.7 nm and 10-30 nm. The solid bitumen (SB) followed by vitrinite and inertinite in kerogen contributes the most to the total kerogen PV.

Application of nitrogen gas-adsorption technique for characterization of pore structure of mudrocks

2013 ◽  
Vol 32 (12) ◽  
pp. 1478-1485 ◽  
Author(s):  
Utpalendu Kuila ◽  
Manika Prasad
Keyword(s):  
Pore Structure ◽  
Gas Adsorption ◽  
Nitrogen Gas

Pore structure characterization of different rank coals using gas adsorption and scanning electron microscopy

Fuel ◽  
2015 ◽  
Vol 158 ◽  
pp. 908-917 ◽  
Author(s):  
Baisheng Nie ◽  
Xianfeng Liu ◽  
Longlong Yang ◽  
Junqing Meng ◽  
Xiangchun Li
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Pore Structure ◽  
Gas Adsorption ◽  
Structure Characterization ◽  
Scanning Electron

Pore characteristics of lacustrine mudstones from the Cretaceous Qingshankou Formation, Songliao Basin

2017 ◽  
Vol 5 (3) ◽  
pp. T373-T386 ◽  
Author(s):  
Min Wang ◽  
Shuangfang Lu ◽  
Wenbiao Huang ◽  
Wei Liu
Keyword(s):  
Organic Matter ◽  
Source Rock ◽  
Gas Adsorption ◽  
Total Pore Volume ◽  
Songliao Basin ◽  
Hydrocarbon Generation ◽  
Shale Oil ◽  
Pore Characteristics ◽  
Oil Accumulation ◽  
Average Pore

Cretaceous Qingshankou ([Formula: see text]) mudstone of lacustrine origin is the major source rock for conventional hydrocarbon currently being produced in the Daqing and Jilin oilfields of the Songliao Basin, which is one of the largest continental basins in the world. Therefore, elucidating the geochemical and petrological characteristics of the [Formula: see text] mudstone is important to help determine its quality as an economically viable source for shale oil production. In our study, eight dark mudstone core samples from the [Formula: see text] formation were subjected to total organic carbon (TOC), Rock-Eval pyrolysis, X-ray diffraction, scanning electron microscopy (SEM), field emission SEM (FE-SEM), and low-pressure [Formula: see text] gas adsorption (LPGA-[Formula: see text]) experiments. Geochemical and petrological analysis results indicated the presence of a high TOC content, which originated mainly from alginate and some plant-derived organic matter, whereas bitumen was frequently present in mudstones with thermal maturity in the oil-generation stage. The [Formula: see text] mudstones were comprised mainly of clay minerals, followed by quartz, feldspar, and carbonates. The LPGA-[Formula: see text] experiments revealed the presence of nanoscale slit-shaped pores, and the contribution from mesopores to the total pore volume was the highest in most of the samples. The average pore diameters (APDs) of the mudstone samples were all smaller than 20 nm (4.36–17.79 nm). We determined that there was a clear positive correlation between the APD and the free oil content; however, there were no clear correlations between the APDs and the quartz, carbonate, and TOC contents. FEM studies revealed the presence of intergranular pores with widths of approximately 10 μm, micron-level autogenetic organic matter pores within spores, organic matter pores caused by the hydrocarbon generation effect within organic matter or clay-organic complexes, and intraparticle pores within clays or pyrite framboids. The microlevel intergranular pores might play an important role in shale oil accumulation from source rock of lacustrine origin.

scholarly journals Pore Structure Petrophysical Characterization of the Upper Cretaceous Oil Shale from the Songliao Basin (NE China) Using Low-Field NMR

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Xin Liu ◽  
Jinyou Zhang ◽  
Yunfeng Bai ◽  
Yupeng Zhang ◽  
Ying Zhao ◽  
...  
Keyword(s):  
Pore Structure ◽  
Oil Shale ◽  
Upper Cretaceous ◽  
Distribution Patterns ◽  
Songliao Basin ◽  
Shale Oil ◽  
Low Field ◽  
Wide Range ◽  
Low Field Nmr

Low-field NMR theory was employed to study the pore structure of the upper cretaceous oil shale, on the basis of fourteen core samples collected from Qingshankou (UCQ) and Nenjiang (UCN) formations in the Songliao basin. Results indicated that the T2 spectra from NMR measurements for collected samples contain a dominant peak at T2 = 1∼10 ms and are able to be categorized as three types—unimodal, bimodal, and trimodal distributions. The various morphologies of T2 spectra indicate the different pore type and variable connection relationship among pores in shale. By contrast, UCN shale has more single pore type and adsorption pores than UCQ shale. Besides, NMR-based measurements provide reliable characterization on shale porosity, which is verified by the gravimetric approach. Porosities in both UCN and UCQ shales have a wide range (2.3%∼12.5%) and suggest the strong heterogeneity, which partly makes the challenge in selection of the favorable area for shale oil exploration in the Songliao basin. In addition, the pore size of the collected sample has two distribution types, namely, peaked at ∼10 nm and peaked at ∼100 nm. Similarly, two distribution patterns emerge to the specific surface area of the study shale—peaked at ∼2 nm−1 and peaked at ∼20 nm−1. Here, more investigations are needed to clarify this polarization phenomenon. Basically, this study not only exhibits a preliminary understanding on the pore structure of the upper cretaceous oil shale, but also shows the reliability and pertinency of the low-field NMR technique in the petrophysical characterization of the shale oil reservoir. It is expected that this work is helpful to guide the investigation on the pore structure of oil shale from the Songliao basin in theory.

Pore structure characterization of low volatile bituminous coals with different particle size and tectonic deformation using low pressure gas adsorption

2017 ◽  
Vol 183 ◽  
pp. 1-13 ◽  
Author(s):  
Shihui Hou ◽  
Xiaoming Wang ◽  
Xingjin Wang ◽  
Yudong Yuan ◽  
Sidong Pan ◽  
...  
Keyword(s):  
Particle Size ◽  
Pore Structure ◽  
Gas Adsorption ◽  
Low Pressure ◽  
Structure Characterization ◽  
Tectonic Deformation ◽  
Bituminous Coals

Experimental Study of the Pore Structure Characterization in Shale With Different Particle Size

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Shuwen Zhang ◽  
Xuefu Xian ◽  
Junping Zhou ◽  
Guojun Liu ◽  
Yaowen Guo ◽  
...  
Keyword(s):  
Particle Size ◽  
Specific Surface ◽  
Pore Structure ◽  
Pore Volume ◽  
Gas Adsorption ◽  
Total Pore Volume ◽  
Structure Characterization ◽  
Particle Sizes ◽  
Average Pore ◽  
Longmaxi Shale

In order to study the effects of particle size on the determination of pore structure in shale, the outcrop of Ordovician Wufeng (WF) and Silurian Longmaxi shale (LMX) samples from Sichuan basin were chosen and crushed into various particle sizes. Then, pore structure was analyzed by using low-pressure gas adsorption (LPGA) tests. The results show that the pore of shales is mainly composed of slit-type pores and open pores. The specific surface areas of shale are mainly contributed by micropores, while the largest proportion of the total pore volume in shale is contributed by mesopores. With the decreasing of particle size, the specific surface area of both samples is decreased, while average pore diameter and the total pore volume are increased gradually. The influences of particle size on the pore structure parameters are more significant for micropore and macropore, as the particle sizes decrease from 2.36 mm to 0.075 mm, the volume of micropores in Longmaxi shale increases from 0.283 cm3/100 g to 0.501 cm3/100 g with an increment almost 40%, while the volume of macropores decreases from 0.732 cm3/100 g to 0.260 cm3/100 g with a decrement about 50%. This study identified the fractal dimensions at relative pressures of 0–0.50 and 0.50–0.995 as D1 and D2, respectively. D1 increases with the decrease of particle size of shale, while D2 shows an opposite tendency in both shale samples.

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