scholarly journals Effect of Shale Sample Particle Size on Pore Structure Obtained from High Pressure Mercury Intrusion Porosimetry

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Zhiye Gao ◽  
Longfei Duan ◽  
Qinhong Hu ◽  
Shuling Xiong ◽  
Tongwei Zhang
Keyword(s):  
Particle Size ◽  
High Pressure ◽  
Pore Structure ◽  
Mercury Intrusion Porosimetry ◽  
Rapid Development ◽  
Structure Characterization ◽  
Barnett Shale ◽  
Skeletal Density ◽  
Mercury Intrusion ◽  
Shale Sample

With the rapid development of unconventional oil and gas, the pore structure characterization of shale reservoirs has attracted an increasing attention. High pressure mercury intrusion porosimetry (HPMIP) has been widely used to quantitatively characterize the pore structure of tight shales. However, the pore structure obtained from HPMIP could be significantly affected by the sample particle size used for the analyses. This study mainly investigates the influence of shale sample particle size on the pore structure obtained from HPMIP, using Mississippian-aged Barnett Shale samples. The results show that the porosity of Barnett Shale samples with different particle sizes obtained from HPMIP has an exponentially increasing relation with the particle size, which is mainly caused by the new pores or fractures created during shale crushing process as well as the increasing exposure of blind or closed pores. The amount and proportion of mercury retention during mercury extrusion process increase with the decrease of shale particle size, which is closely related to the increased ink-bottle effect in shale sample with smaller particle size. In addition, the fractal dimension of Barnett Shale is positively related to the particle size, which indicates that the heterogeneity of pore structure is stronger in shale sample with larger particle size. Furthermore, the skeletal density of shale sample increases with the decrease of particle size, which is possibly caused by the differentiation of mineral composition during shale crushing process.

scholarly journals FRACTAL CHARACTERIZATION OF TIGHT OIL RESERVOIR PORE STRUCTURE USING NUCLEAR MAGNETIC RESONANCE AND MERCURY INTRUSION POROSIMETRY

Fractals ◽  
2018 ◽  
Vol 26 (02) ◽  
pp. 1840017 ◽  
Author(s):  
FUYONG WANG ◽  
KUN YANG ◽  
JIANCHAO CAI
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Pore Structure ◽  
Pore Size ◽  
Mercury Intrusion Porosimetry ◽  
Fractal Dimensions ◽  
Structure Characterization ◽  
Tight Oil ◽  
Petrophysical Properties ◽  
Mercury Intrusion

Tight oil sandstones have the characteristics of narrow pore throats, complex pore structures and strong heterogeneities. Using nuclear magnetic resonance (NMR) and mercury intrusion porosimetry (MIP), this paper presents an advanced fractal analysis of the pore structures and petrophysical properties of the tight oil sandstones from Yanchang Formation, Ordos Basin of China. Firstly, nine typical tight oil sandstone core samples were selected to conduct NMR and MIP test for pore structure characterization. Next, with the pore size distribution derived from MIP, it was found that the relationships between NMR transverse relaxation time [Formula: see text] and pore size are more accordant with the power function relations, which were applied to derive pore size distribution from NMR rather than the linear relation. Moreover, fractal dimensions of micropores, mesopores and macropores were calculated from NMR [Formula: see text] spectrum. Finally, the relationships between the fractal dimensions of different size pores calculated from NMR [Formula: see text] spectrum and petrophysical properties of tight oil sandstones were analyzed. These studies demonstrate that the combination of NMR and MIP can improve the accuracy of pore structure characterization and fractal dimensions calculated from NMR [Formula: see text] spectrum are effective for petrophysical properties analysis.

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.

Study on pore structure evaluation of shale gas reservoir-Taking the Lower Cambrian Niutitang Formation in the Cenggong Block, Guizhou Province as an example

2020 ◽  
pp. 1-25
Author(s):  
Fuqiang Lai ◽  
Haiyan Mao ◽  
Jianping Bai ◽  
Daijan Gong ◽  
Guotong Zhang ◽  
...  
Keyword(s):  
High Pressure ◽  
Pore Structure ◽  
Structure Parameters ◽  
Pore Throat ◽  
Throat Radius ◽  
Volume Percentage ◽  
Nmr Logging ◽  
Mercury Intrusion ◽  
Niutitang Formation ◽  
Structure Evaluation

The storage and seepage space of shale is mainly composed of pores and fractures, while the microscopic pore structure and fracture distribution are very complicated. The accuracy of calculation of pore structure parameters is related to whether the reservoir evaluation is correct and effective. Taking the Niutitang Formation in the Cengong area of Guizhou as the research object. Firstly, based on the Archie formula, the process of the wellbore mud intrusion is approximated as the process of the laboratory high pressure mercury intrusion, combined with conventional and nuclear magnetic resonance logging data. The formula deduces a new model for the T2 spectrum conversion pseudo-capillary pressure curve. Then the model is calibrated by the high pressure mercury intrusion experimental data, and the pore structure parameters such as reservoir pore size distribution curve and maximum pore throat radius are calculated. The results show that the maximum pore throat radius and total porosity data calculated by NMR logging are relatively reliable, the median radius error is general, and the displacement pressure and median pressure error are relatively large. The pore volume percentage of 1-10 μm is up to 60%, and the micro-cracks are relatively developed, which is beneficial to the fracturing of the reservoir. Therefore, the use of NMR logging data combined with conventional logging can better reflect the pore structure characteristics of reservoirs, which provides a strong support for complex reservoir identification and qualitative prediction of productivity, and has a good application prospect.

scholarly journals Ink-bottle Effect and Pore Size Distribution of Cementitious Materials Identified by Pressurization–Depressurization Cycling Mercury Intrusion Porosimetry

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1454 ◽  
Author(s):  
Yong Zhang ◽  
Bin Yang ◽  
Zhengxian Yang ◽  
Guang Ye
Keyword(s):  
Pore Structure ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Mercury Intrusion Porosimetry ◽  
Cementitious Materials ◽  
Limestone Powder ◽  
Accurate Estimation ◽  
Mercury Intrusion ◽  
Pore Size Distributions

Capturing the long-term performance of concrete must be underpinned by a detailed understanding of the pore structure. Mercury intrusion porosimetry (MIP) is a widely used technique for pore structure characterization. However, it has been proven inappropriate to measure the pore size distribution of cementitious materials due to the ink-bottle effect. MIP with cyclic pressurization–depressurization can overcome the ink-bottle effect and enables a distinction between large (ink-bottle) pores and small (throat) pores. In this paper, pressurization–depressurization cycling mercury intrusion porosimetry (PDC-MIP) is adopted to characterize the pore structure in a range of cementitious pastes cured from 28 to 370 days. The results indicate that PDC-MIP provides a more accurate estimation of the pore size distribution in cementitious pastes than the standard MIP. Bimodal pore size distributions can be obtained by performing PDC-MIP measurements on cementitious pastes, regardless of the age. Water–binder ratio, fly ash and limestone powder have considerable influences on the formation of capillary pores ranging from 0.01 to 0.5 µm.

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