scholarly journals The Spontaneous Imbibition of Micro/Nano Structures in Tight Matrix and the Influence on Imbibition Potential

Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 794
Author(s):  
Caoxiong Li ◽  
Chenggang Xian ◽  
Jun Wang ◽  
Dandan Geng ◽  
Yinghao Shen
Keyword(s):  
Pore Structure ◽  
Fractal Theory ◽  
Gas Production ◽  
Spontaneous Imbibition ◽  
Key Factors ◽  
Pore Connectivity ◽  
Fractal Properties ◽  
The Matrix ◽  
And Diffusion ◽  
Specific Scale

Tight matrix has relatively low permeability and porosity, with abundant micro/nano pores. The capillary force in these pores are relatively strong, making the wetting liquid easier to be imbibed in the matrix. This process is called spontaneous imbibition. The complexity of pore structure is identified as one of the key factors influencing the imbibition process, but the detailed mechanism is not clear. Thus, in this work, a method is proposed to evaluate the influence of pore structure on imbibition process. Pore structure has fractal properties in a specific scale. By using the fractal theory, an imbibition model is provided to analyze the influence of microscopic structures on spontaneous imbibition, considering the pore size distribution and pore connectivity. Also, based on this model, the influencing factors on dimensionless imbibition and diffusion rate are discussed. Results show that the pore structure has more branches, larger and shorter sub-throats has higher chance to gain a high imbibition rate. Finally, a 3D imbibition parameter cube is constructed to determine the parameter combinations in favor of strong water diffusion potential. By utilizing the analysis method based on the fractal theory, we can effectively evaluate the imbibition potential. It is helpful to provide a guidance to evaluate the water imbibition to gas production.

scholarly journals SPONTANEOUS IMBIBITION PROCESS IN MICRO–NANO FRACTAL CAPILLARIES CONSIDERING SLIP FLOW

Fractals ◽  
2018 ◽  
Vol 26 (02) ◽  
pp. 1840002 ◽  
Author(s):  
YINGHAO SHEN ◽  
CAOXIONG LI ◽  
HONGKUI GE ◽  
XUEJING GUO ◽  
SHAOJUN WANG
Keyword(s):  
Fluid Transport ◽  
Slip Length ◽  
Fractal Theory ◽  
Slip Flow ◽  
Gas Production ◽  
Spontaneous Imbibition ◽  
Equivalent Diameter ◽  
Slip Effect ◽  
Analytic Equation ◽  
Slip Boundary

An imbibition process of water into a matrix is required to investigate the influences of large-volume fracturing fluids on gas production of unconventional formations. Slip flow has been recognized by recent studies as a major mechanism of fluid transport in nanotubes. For nanopores in shale, a slip boundary is nonnegligible in the imbibition process. In this study, we established an analytic equation of spontaneous imbibition considering slip effects in capillaries. A spontaneous imbibition model that couples the analytic equation considering the slip effect was constructed based on fractal theory. We then used a model for various conditions, such as slip boundary, pore structure, and fractal dimension of pore tortuosity, to capture the imbibition characteristics considering the slip effect. A dynamic contact angle was integrated into the modeling. Results of our study verify that the slip boundary influences water imbibition significantly. The imbibition speed is significantly improved when slip length reaches the equivalent diameter of a tube. Therefore, disregarding the slip effect will underestimate the imbibition speed in shale samples.

scholarly journals Pore Connectivity Characterization Using Coupled Wood’s Metal Intrusion and High-Resolution Imaging: A Case of the Silurian Longmaxi Shales From the Sichuan Basin, China

2021 ◽  
Vol 9 ◽  
Author(s):  
Lingjie Yu ◽  
Keyu Liu ◽  
Ming Fan ◽  
Zhejun Pan
Keyword(s):  
Ion Beam ◽  
Three Dimensional ◽  
Gas Production ◽  
Micro Ct ◽  
Pore Connectivity ◽  
X Ray ◽  
Pore Networks ◽  
The Matrix ◽  
Siliceous Shale ◽  
Pore Types

Pore connectivity is crucial for shale gas production. However, the three-dimensional (3D) characteristics and distribution of pore networks and, more fundamentally, the underlying role of different pore types on pore connectivity in shales are inadequately understood. By comparing the 3D pore connectivity derived from direct microstructural imaging of pores filled with Wood’s metal at a pressure corresponding to the finest accessible pore throat in the resolution ranges that may be achieved by X-ray micro-CT and SEM, it is possible to evaluate pore connectivity of different types of shales. The pore connectivity of three shales including a mixed mudstone, siliceous shale, and argillaceous shale from the Silurian Longmaxi Formations is investigated via combined broad ion beam (BIB) polishing, and SEM and X-ray micro-CT imaging after Wood’s metal injection at a pressure up to 380 MPa. The three shales show significant differences in pore connectivity. The mixed mudstone shows excellent pore connectivity in the matrix; the siliceous shale shows an overall poor connectivity with only a small amount of OM (organic matter) pores immediately adjacent to microfractures displaying interconnectivity, while the pores in the argillaceous shale, dominated by plate-like clay pores, are largely not interconnected.

Does Vitamin K Intake Influence High Phosphate Induced Vascular Pseudo-ossification: An Underappreciated Therapeutic Prospect in General Population?

2019 ◽  
Vol 20 (4) ◽  
pp. 421-430
Author(s):  
Zar Chi Thent ◽  
Gabriele R.A. Froemming ◽  
Suhaila Abd Muid
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Vascular Calcification ◽  
Vitamin K ◽  
Prolonged Exposure ◽  
Vascular Complication ◽  
Key Factors ◽  
The Matrix ◽  
Underlying Mechanisms ◽  
High Phosphate

Increasing interest in vascular pseudo-ossification has alarmed the modern atherosclerotic society. High phosphate is one of the key factors in vascular pseudo ossification, also known as vascular calcification. The active process of deposition of the phosphate crystals in vascular tissues results in arterial stiffness. High phosphate condition is mainly observed in chronic kidney disease patients. However, prolonged exposure with high phosphate enriched foods such as canned drinks, dietary foods, etc. can be considered as modifiable risk factors for vascular complication in a population regardless of chronic kidney disease. High intake of vitamin K regulates the vascular calcification by exerting its anti-calcification effect. The changes in serum phosphate and vitamin K levels in a normal individual with high phosphate intake are not well investigated. This review summarised the underlying mechanisms of high phosphate induced vascular pseudo ossification such as vascular transdifferentiation, vascular apoptosis and phosphate uptake by sodium-dependent co-transporters. Pubmed, Science Direct, Scopus, ISI Web of Knowledge and Google Scholar were searched using the terms ‘vitamin K’, ‘vascular calcification, ‘phosphate’, ‘transdifferentiation’ and ‘vascular pseudoossification’. Vitamin K certainly activates the matrix GIA protein and inhibits vascular transition and apoptosis in vascular pseudo-ossification. The present view highlighted the possible therapeutic linkage between vitamin K and the disease. Understanding the role of vitamin K will be considered as potent prophylaxis agent against the vascular disease in near future.

FRACTAL MODELS FOR GAS–WATER TRANSPORT IN SHALE POROUS MEDIA CONSIDERING WETTING CHARACTERISTICS

Fractals ◽  
2020 ◽  
Vol 28 (07) ◽  
pp. 2050138
Author(s):  
QI ZHANG ◽  
XINYUE WU ◽  
QINGBANG MENG ◽  
YAN WANG ◽  
JIANCHAO CAI
Keyword(s):  
Fractal Dimension ◽  
Pore Structure ◽  
Pore Pressure ◽  
Surface Diffusion ◽  
Water Transport ◽  
Relative Permeability ◽  
Fluid Transport ◽  
Water Saturation ◽  
Fractal Theory ◽  
Gas Slippage

Complicated gas–water transport behaviors in nanoporous shale media are known to be influenced by multiple transport mechanisms and pore structure characteristics. More accurate characterization of the fluid transport in shale reservoirs is essential to macroscale modeling for production prediction. This paper develops the analytical relative permeability models for gas–water two-phase in both organic and inorganic matter (OM and IM) of nanoporous shale using the fractal theory. Heterogeneous pore size distribution (PSD) of the shale media is considered instead of the tortuous capillaries with uniform diameters. The gas–water transport models for OM and IM are established, incorporating gas slippage described by second-order slip condition, water film thickness in IM, surface diffusion in OM, and the total organic carbon. Then, the presented model is validated by experimental results. After that, sensitivity analysis of gas–water transport behaviors based on pore structure properties of the shale sample is conducted, and the influence factors of fluid transport behaviors are discussed. The results show that the gas relative permeability is larger than 1 at the low pore pressure and water saturation. The larger pore pressure causes slight effect of gas slippage and surface diffusion on the gas relative permeability. The larger PSD fractal dimension of IM results in larger gas relative permeability and smaller water relative permeability. Besides, the large tortuosity fractal dimension will decrease the gas flux at the same water saturation, and the surface diffusion decreases with the increase of tortuosity fractal dimension of OM and pore pressure. The proposed models can provide an approach for macroscale modeling of the development of shale gas reservoirs.

FRACTAL PORE STRUCTURE MODEL AND MULTILAYER FRACTAL ADSORPTION IN SHALE

Fractals ◽  
2014 ◽  
Vol 22 (03) ◽  
pp. 1440010 ◽  
Author(s):  
LIEHUI ZHANG ◽  
JIANCHAO LI ◽  
HONGMING TANG ◽  
JINGJING GUO
Keyword(s):  
Fractal Dimension ◽  
Pore Structure ◽  
Saturated Vapor ◽  
Adsorption Property ◽  
Fractal Theory ◽  
Complex Structure ◽  
Structure Model ◽  
Adsorption Model ◽  
Adsorption Volume ◽  
Isothermal Adsorption

The complex structure and surface property of porous media have significant impact on its accumulation and adsorption capacity. Based on the fractal theory, this paper presents a fractal pore structure model for shales. The effect of different pore structures on fractal dimension is discussed, and the influence of fractal dimension and pore size distribution on porosity is also analyzed. It is shown that the fractal dimension D decreases with the increase of structure parameter q/m for a certain pore diameter ratio, and porosity has positive relationship with fractal dimension. This paper also presents a multilayer fractal adsorption model which takes into account the roughness of adsorption surface by using fractal theory. With the introduction of pseudo-saturated vapor pressure in the supercritical temperature condition, the proposed adsorption model can be applied into a wider range of temperature. Based on the low-pressure nitrogen adsorption and methane isothermal adsorption experiments, the effect of fractal dimension on the adsorption behavior of shales is discussed. Fractal dimension has significant impact on the surface adsorption property and adsorption layer number n. The monolayer saturated adsorption volume Vm increases with the increase of D, while parameter C has the opposite variation trend. Finally, the optimal combination of fractal parameters for describing pore structure of shale samples is selected.

scholarly journals Pengembangan Pasar Tenun Serat PT Retota Sakti Kabupaten Pekalongan, Jawa Tengah

2014 ◽  
Vol 9 (1) ◽  
pp. 54-66
Author(s):  
Hari Subagyo ◽  
Mochamad Hasjim Bintoro ◽  
Parulian Hutagaol
Keyword(s):  
Production Management ◽  
Swot Analysis ◽  
Production Capacity ◽  
Marketing Strategies ◽  
Matrix Analysis ◽  
Key Factors ◽  
Five Factors ◽  
The Matrix ◽  
Market Needs ◽  
Internal And External Factors

Potential weaving industry nationally as one of the SMEs so far have not unearthed the maximum due to the development of production management systems. Therefor,  PT Retota Sakti has prompted company management to enhance the creative abilities tenunnya always accompanied by the application of more precise marketing strategies that correspond with the development of competition situation that occurred in the weaving industry. The purpose of this study was (1) Identify and evaluate the position of Marketing PT Retota Way by internal and external factors, and (2) Develop appropriate marketing strategies in developing future business. Analyzed in a descriptive study to emphasize the aspect of marketing, covering demand products to meet market needs; offer, which gives an overview about the availability of products in the process of cultivation and the balance of factors between demand and supply prices. To examine the marketing strategies carried out by quantitative SWOT analysis. The results of factor identification strategy, there are five key factors of internal strengths and weaknesses of four key factors. While the external environment there are five key factors of opportunities and threats of five factors. IFE values ​​2.842 and 2.530 EFE value, and also the combination of these two values ​​in the matrix IE indicates that the marketing strategy lies in the quadrant of five, namely the growth and stability, where the strategies that can run the market penetration, product development and market. QSP matrix analysis results obtained with the most attractive strategy to be implemented is to increase production capacity.

scholarly journals Effect of Grain Size on Microscopic Pore Structure and Fractal Characteristics of Carbonate-Based Sand and Silicate-Based Sand

2021 ◽  
Vol 5 (4) ◽  
pp. 152
Author(s):  
Shao-Heng He ◽  
Zhi Ding ◽  
Hai-Bo Hu ◽  
Min Gao
Keyword(s):  
Grain Size ◽  
Fractal Dimension ◽  
Pore Structure ◽  
Pore Size ◽  
Quartz Sand ◽  
Glass Bead ◽  
Fractal Theory ◽  
Calcareous Sand ◽  
Wide Range ◽  
Fractal Characteristics

In this study, a series of nuclear magnetic resonance (NMR) tests was conducted on calcareous sand, quartz sand, and glass bead with a wide range of grain sizes, to understand the effect of grain size on the micro-pore structure and fractal characteristics of the carbonate-based sand and silicate-based sand. The pore size distribution (PSD) of the tested materials were obtained from the NMR T2 spectra, and fractal theory was introduced to describe the fractal properties of PSD. Results demonstrate that grain size has a significant effect on the PSD of carbonate-based sand and silicate-based sand. As grain size increases, the PSD of sands evolves from a binary structure with two peaks to a ternary structure with three peaks. The increase in the grain size can cause a remarkable increase in the maximum pore size. It is also found that the more irregular the particle shape, the better the continuity between the large and medium pores. In addition, grain size has a considerable effect on the fractal dimension of the micro-pore structure. The increase of grain size can lead to a significant increase in the heterogeneity and fractal dimension in PSD for calcareous sand, quartz sand and glass bead.

STUDY ON EVOLUTION OF FRACTAL DIMENSION FOR FRACTURED COAL SEAM UNDER MULTI-FIELD COUPLING

Fractals ◽  
2020 ◽  
Vol 28 (04) ◽  
pp. 2050072 ◽  
Author(s):  
GUANNAN LIU ◽  
BOMING YU ◽  
DAYU YE ◽  
FENG GAO ◽  
JISHAN LIU
Keyword(s):  
Fractal Dimension ◽  
Coal Seam ◽  
Pore Structure ◽  
Fractal Theory ◽  
In Situ Stress ◽  
Volume Strain ◽  
Fracture Length ◽  
Field Coupling ◽  
Pore Evolution ◽  
Fractured Coal

In the process of gas extraction, fracture-pore structure significantly influences the macroscopic permeability of coal seam. However, under the multi-field coupling, the mechanism of coal seam fracture-pore evolution remains to be clarified. In this paper, considering the effect of adsorption expansion, the fractal theory for porous media coupled with the multi-field model for coal seam is considered, and a multi-field coupling mechanical model is constructed by considering the influence of fracture-pore structure. Furthermore, the evolution mechanism of fractal dimension with physical and mechanical parameters of coal seam is studied. It is found that the fractal dimension for coal seam is inversely proportional to mining time and in situ stress, proportional to elastic modulus, Langmuir volume constant and Langmuir volume strain constant, and inversely proportional to Langmuir pressure constant. Compared with other factors, Langmuir pressure constant and Langmuir volume strain constant have the significance influence on the fractal dimension for the fracture length.

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