Xinshan Zhuang^*, Shunlei Xia, Ruijie Pan

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.2, pp. 447-461, 2024, DOI:10.32604/fdmp.2023.042220

Abstract Clay, as the most common soil used for foundation fill, is widely used in various infrastructure projects. The physical and mechanical properties of clay are influenced by the pore solution environment. This study uses a GDS static/dynamic triaxial apparatus and nuclear magnetic resonance experiments to investigate the effects of cyclic loading on clay foundations. Moreover, the development of cumulative strain in clay is analyzed, and a fitting model for cumulative plastic strain is introduced by considering factors such as NaCl solution concentration, consolidation stress ratio, and cycle number. In particular, the effects of the NaCl solution concentration and consolidation stress… More >

Yiguo Chen^1,2,3,*, Congjun Feng^1,2, Yonghong He³, Zhijun Chen³, Xiaowei Fan³, Chao Wang³, Xinmin Ge⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.136, No.3, pp. 2451-2463, 2023, DOI:10.32604/cmes.2023.021145

Abstract The low-field nuclear magnetic resonance (NMR) technique has been used to probe the pore size distribution and the fluid composition in geophysical prospecting and related fields. However, the speed and accuracy of the existing numerical inversion methods are still challenging due to the ill-posed nature of the first kind Fredholm integral equation and the contamination of the noises. This paper proposes a novel inversion algorithm to accelerate the convergence and enhance the precision using empirical truncated singular value decompositions (TSVD) and the linearized Bregman iteration. The L1 penalty term is applied to construct the objective function, and then the linearized… More > Graphic Abstract

Yanyue Li¹, Changlong Liu¹, Wenbo Bao^1,*, Baoqing Xue¹, Peng Lv¹, Nan Wang¹, Hui Li¹, Wenguo Ma²

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.3, pp. 737-749, 2022, DOI:10.32604/fdmp.2022.019139

Abstract

Due to long-term water injection, often oilfields enter the so-called medium and high water cut stage, and it is difficult to achieve good oil recovery and water reduction through standard methods (single profile control and flooding measures). Therefore, in this study, a novel method based on “plugging, profile control, and flooding” being implemented at the same time is proposed. To assess the performances of this approach, physical simulations, computer tomography, and nuclear magnetic resonance are used. The results show that the combination of a gel plugging agent, a polymer microsphere flooding agent, and a high-efficiency oil displacement agent leads to… More >

Xing Zhang^*

Energy Engineering, Vol.118, No.5, pp. 1453-1467, 2021, DOI:10.32604/EE.2021.015032

Abstract Polymer has been successfully used to enhance crude oil recovery at high water cut stage. However, the application of polymer flooding is limited by the heterogeneity of reservoir. In this work, the role of polymer flooding in heterogeneous reservoir was explored by nuclear magnetic resonance (NMR) spectroscopy. Parallel core displacement experiments were carried out to study polymer flooding in heterogeneous formation. The results showed that the polymer flooding area was related to permeability and pore connectivity. At the end of the water flooding stage, the residual oil was not evenly distributed in porous media. The percent crude oil recovery increased… More >

Yong Wang, Yongyan Wang^*, Nan Qin, Sa Huang, Le Chang, Shunzheng Hou

Computer Systems Science and Engineering, Vol.39, No.1, pp. 121-131, 2021, DOI:10.32604/csse.2021.014464

Abstract The work presented in this paper was conducted to quantify the relationship between the pore characteristics and mechanical properties of white sandstone. The study include tests carried out under the coupling effects of chemical corrosion, temperature, nuclear magnetic resonance, and mechanical tests. Computer fractal theory was employed to describe and quantify the characteristics of the growth of pores in white sandstone under the same coupling effect. A custom developed program code, in the MATLAB software platform, was used for calculating the growths of the pores in white sandstone when subjected to coupling effects. The correlation between the computer fractal dimension… More >

J.P. Tang^*, Y.S. Pan

The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.4, pp. 107-108, 2011, DOI:10.3970/icces.2011.016.107

Abstract Nuclear Magnetic Resonance (NMR) as an advanced non-damaged measurement technique was introduced into the research of gas adsorption and desorption in coal to simulate physically and evaluate influence of tridimensional load and unload . Coal is typical heterogeneous material which can adsorb gas. Load and unload condition play important roles for gas storage and transport in coal. Gas in coal has two states, free and absorbed which act balance dynamically. The home-made triaxial osmoscope made up of non-magnetic polycarbonate material which has coal sample were placed into the magnetic bore of NMR spectrum equipment. The NMR spectrum experiments of coal… More >