Pore structure characteristics of tight sandstones in the northern Songliao Basin, China

Zhang, Luchuan; Lu, Shuangfang; Xiao, Dianshi; Li, Bo

doi:10.1016/j.marpetgeo.2017.08.005

Cited by 101 publications

(64 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The scattered point of the sandstone can be divided into two segments obviously, and the inflection points are related to the capillary pressure indicating that pore structures in the uranium-bearing sandstone have two apparent pore types with different pore connectivity in the samples. 33,38 In addition, it can be seen that the slope for the smaller pore under cumulative volume method is rather steep, and the slope for the smaller pore under cumulative surface area method is still rather steep than that for the larger pore, reflecting significant differences between the larger and smaller pore in the uranium sandstone.…”

Section: Double Fractal Characteristicsmentioning

confidence: 97%

“…All the linear models are well fitted with coefficients ranging from 0.89 to 0.99 with an average of 0.97 (Table 6). 33 According to the results from Sakhaee-Pour and Brayant, 45 the double fractal structure corresponds to an intergranulardominant region and an intragranular-dominant region. 33 According to the results from Sakhaee-Pour and Brayant, 45 the double fractal structure corresponds to an intergranulardominant region and an intragranular-dominant region.…”

Section: Double Fractal Characteristicsmentioning

confidence: 99%

“…This indicates that the tested sandstone samples are fractal and therefore can be quantitatively described by fractal geometry theory, it also suggests that the pore volume and specific surface of the This phenomenon is different from the pore structures in the tight sandstone that may only have a unique fractal region. As Zhang et al 33 pointed out, pores in the intergranular-dominant region mainly consist of intergranular pores and dissolution pores, while the pores in the intragranular-dominant region are comprised of intercrystalline pores. It can be seen that pores in the uranium-bearing sandstone can be divided into the intergranular macropores and the intragranular micropores.…”

Section: Double Fractal Characteristicsmentioning

confidence: 99%

“…23 There are a number of technologies that can be used for characterizing the surface morphology and pore structure of sandstone with the aid of fractal theory. 33,34 However, different experimental methods have their own pros and cons due to the different testing principles and limitations of the testing scope. 33,34 However, different experimental methods have their own pros and cons due to the different testing principles and limitations of the testing scope.…”

mentioning

confidence: 99%

“…The fluid invasion, gas adsorption, and image analysis methods are widely utilized to calculate the fractal dimension of the sandstone such as scanning electron microscopy (SEM) tests, 24,25 mercury injection capillary pressure (MICP) tests, 22,26 particle size distribution (PSD) tests, 27,28 nuclear magnetic resonance (NMR) measurements, 29,30 computed tomography (CT) scans, 31,32 and nitrogen gas adsorption (N 2 GA). 33,34 However, different experimental methods have their own pros and cons due to the different testing principles and limitations of the testing scope. For examples, the SEM tests can accurately determine the size and type of pores from the nano-to micron-scale, as well as the mode of minerals occurrence, while the high cost of testing and the difficulty of image processing make it uneconomical and hard to popularize.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Fractal characteristics of uranium‐bearing sandstone structure and their effects on acid leaching

Zeng

Zhang

et al. 2019

Energy Science & Engineering

View full text Add to dashboard Cite

Pore structure characteristics have significant effects on the flow distribution, seepage characteristics, and reaction mechanism of the leachate as well as the uranium leaching efficiency in‐situ leaching (ISL) of uranium. In this study, a series of experiments including mercury injection and uranium leaching were conducted to study the characteristics of the pore structure and their effects on uranium leaching. The following conclusions can be drawn: The distribution of uranium‐bearing sandstone particle size shows the double fractal characteristic, and the particle size can be divided into coarse particles (r > 0.6 mm) and fine particles (r ≤ 0.6 mm). Furthermore, the pore volume and specific surface area of uranium sandstone both have dual fractal features corresponding to an intergranular‐dominant region and intragranular‐dominant region from mercury injection results. Fractures in the uranium‐bearing sandstone may be the main factors that lead to the abnormal fractal dimensions of pore structure. The uranium leaching efficiency of the sandstone increase with the leaching time and reach the maximum value (above 90%) at the 112th hour, and the whole leaching process can be divided into two phases taking the 60th hour as the demarcation point. Through correlation analysis, fractal dimension of the particle size, pore volume, and specific surface area was significantly correlated with the leaching efficiency of uranium at different dissolution phase. Corresponding measures such as adjusting solutions concentration and adding hydrofluoric acid can be taken to avoid the negative effect of pore structure. Those observations can provide a theoretical reference for the optimization of the leaching period and site design parameters of uranium‐bearing sandstone.

show abstract

Section: Double Fractal Characteristicsmentioning

confidence: 97%

Section: Double Fractal Characteristicsmentioning

confidence: 99%

Section: Double Fractal Characteristicsmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Fractal characteristics of uranium‐bearing sandstone structure and their effects on acid leaching

Zeng

Zhang

et al. 2019

Energy Science & Engineering

View full text Add to dashboard Cite

show abstract

Digital Rock Modeling

Tahmasebi

2023

Physics of Fluid Flow and Transport in Unconventional Reservoir Rocks

View full text Add to dashboard Cite

Pore structure of tight sandstones with differing permeability: The He 8 Member of the Middle Permian Lower Shihezi Formation, Gaoqiao area, Ordos Basin

Chen,

Zhu,

Wang

et al. 2023

Energy Science & Engineering

View full text Add to dashboard Cite

Tight sandstone has strong pore heterogeneity and complex pore structure, and the pore structure of tight sandstone varies with different permeability. To study the differences in the pore structure of tight sandstone with different permeability, this study investigated the tight sandstone of the He 8 Member in the Gaoqiao area of the Ordos Basin. Factors influencing pore formation are analyzed through experiments utilizing methods, such as distinguishing casting thin sections, scanning electron microscopy, high‐pressure mercury intrusion, and low‐temperature nitrogen adsorption. The results indicate that in this area, the pores of the tight sandstone are primarily dissolution and intercrystalline pores, with occasional intergranular pores and microcracks. Type Ⅱ samples (permeability > 0.2 × 10−3 μm2) are primarily composed of dissolution and intercrystalline pores, with a few visible intergranular and microcracks. In contrast, Type Ⅰ samples (permeability < 0.2 × 10−3 μm2) mainly consist of micropores and intercrystalline pores, where microcracks are observed locally. Pore size research demonstrates that Type Ⅰ samples have pore size under 1000 nm, with peaks primarily at 4–5 nm. There are also peaks between 10–1000 nm, but without a consistent pattern. For Type Ⅱ samples with sizes smaller than 1000 nm, pore distribution is evident. Peak values when the pore size exceeds 1000 nm. Type Ⅰ samples have fewer micron‐level pores, while Type Ⅱ samples are primarily dissolution pores. The nanopores of Type Ⅰ samples consist of flat pores with good connectivity, whereas those of Type Ⅱ samples are mainly blind pores with poor connectivity. Type Ⅰ samples have larger pore fractal dimensions, more intricate pore morphology, and rougher and irregular pore throat surfaces compared to Type II samples. Hence, the sedimentary environment, diagenesis, and mineral composition affect the pore distribution in tight sandstone. The research findings highlight the variations in the pore structure of tight sandstone with varying permeability, providing crucial guidance for classifying and assessing pore structure in tight sandstone reservoirs.

show abstract

Pore structure characteristics of tight sandstones in the northern Songliao Basin, China

Cited by 101 publications

References 41 publications

Fractal characteristics of uranium‐bearing sandstone structure and their effects on acid leaching

Fractal characteristics of uranium‐bearing sandstone structure and their effects on acid leaching

Digital Rock Modeling

Pore structure of tight sandstones with differing permeability: The He 8 Member of the Middle Permian Lower Shihezi Formation, Gaoqiao area, Ordos Basin

Contact Info

Product

Resources

About