Yuanyuan Yang¹, Xian Shi^1,2,*, Cheng Ji³, Yujie Yan³, Na An³, Teng Zhang⁴

Energy Engineering, Vol.121, No.12, pp. 3667-3688, 2024, DOI:10.32604/ee.2024.056266 - 22 November 2024

Abstract Based on a geology-engineering sweet spot evaluation, the high-quality reservoir zones and horizontal well landing points were determined. Subsequently, fracture propagation and production were simulated with a multilayer fracturing scenario. The optimal hydraulic fracturing strategy for the multilayer fracturing network was determined by introducing a vertical asymmetry factor. This strategy aimed to minimize stress shadowing effects in the vertical direction while maximizing the stimulated reservoir volume (SRV). The study found that the small vertical layer spacing of high-quality reservoirs and the presence of stress-masking layers (with a stress difference of approximately 3~8 MPa) indicate that… More > Graphic Abstract

Nuttida Chanhom¹, Tossapon Katongtung², Nakorn Tippayawong^2,*

Energy Engineering, Vol.121, No.12, pp. 3649-3665, 2024, DOI:10.32604/ee.2024.054862 - 22 November 2024

Abstract This study investigated the conversion of sugars into furan derivatives, specifically 2,5-dimethylfuran, through catalytic processes using bibliographic analysis. This method evaluates scientific outcomes and impact within a specific field by analyzing data such as publication trends, references, collaborative models, leading authors, and institutions. The study utilized data from the reliable Scopus database and conducted analysis using the visualization of similarity (VOS) viewer program to gain in-depth insights into the current state of research on this topic. The findings revealed that “5 hydroxymethyl furfural” was the most used keyword, followed by “biomass” and “catalysis.” The research More >

Fengxia Shi^1,2, Guangbiao Zhao^1,*, Yucai Tang¹, Dedong Ma¹, Xiangyun Shi¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.11, pp. 2617-2636, 2024, DOI:10.32604/fdmp.2024.053186 - 28 October 2024

Abstract To analyze the effect of blade number on the performance of hydraulic turbines during the transient stage in which the flow rate is not constant, six hydraulic turbines with different blade numbers are considered. The instantaneous hydraulic performance of the turbine and the pressure pulsation acting on the impeller are investigated numerically by using the ANSYS CFX software. The ensuing results are compared with the outcomes of experimental tests. It is shown that the fluctuation range of the pressure coefficient increases with time, but the corresponding range for the transient hydraulic efficiency decreases gradually when… More >

Fan Yang^1,2,*, Honggang Mi^1,2, Jian Wu^1,2, Qi Yang^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.11, pp. 2637-2656, 2024, DOI:10.32604/fdmp.2024.048574 - 28 October 2024

Abstract The gas production of deep coalbed methane wells in Linxing-Shenfu block decreases rapidly, the water output is high, the supporting effect is poor, the effective supporting fracture size is limited, and the migration mechanism of proppant in deep coal reservoir is not clear at present. To investigate the migration behavior of proppants in complex fractures during the volume reconstruction of deep coal and rock reservoirs, an optimization test on the conductivity of low-density proppants and simulations of proppant migration in complex fractures of deep coal reservoirs were conducted. The study systematically analyzed the impact of… More >

Shangjun Gao^1,2, Yang Yang¹, Man Chen¹, Jian Zheng¹, Luqi Qin^2,*, Xiangyu Liu², Jianying Yang¹

Energy Engineering, Vol.121, No.11, pp. 3305-3329, 2024, DOI:10.32604/ee.2024.053622 - 21 October 2024

Abstract Horizontal well drilling and multi-stage hydraulic fracturing are key technologies for the development of shale gas reservoirs. Instantaneous acquisition of hydraulic fracture parameters is crucial for evaluating fracturing effectiveness, optimizing processes, and predicting gas productivity. This paper establishes a transient flow model for shale gas wells based on the boundary element method, achieving the characterization of stimulated reservoir volume for a single stage. By integrating pressure monitoring data following the pumping shut-in period of hydraulic fracturing for well testing interpretation, a workflow for inverting fracture parameters of shale gas wells is established. This new method… More >

Wenhao Shen^1,2,*, Moubin Liu²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.29, No.2, pp. 1-1, 2024, DOI:10.32604/icces.2024.011418

Abstract In this talk, we will present a SPH formulation for coupled Thermal-Hydraulic-Mechanical processes. The Biot’s theory is used to model the fluid-solid interaction of saturated porous media, the Fourier’s law and the Newton’s law of cooling are used to describe the thermal conduction in a single medium and the heat exchange between the fluid and the solid, respectively. The physical model is expressed in the initial reference, and the total Lagrangian SPH is used to build the discrete formulation. We will discuss the numerical instability induced by twice repeated derivatives of discontinuous physical quantities, and More >

Boyu Liu¹, Jun Yao^1,*, Hai Sun¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.29, No.1, pp. 1-1, 2024, DOI:10.32604/icces.2024.011600

Abstract The temperature gradient between the geological formation and the injected supercritical CO₂ (Sc-CO₂) initiates heat transfer processes, leading to a non-uniform temperature field within the fracture. This spatial thermal variation induces fluctuations in the density and viscosity of Sc-CO₂. Moreover, the non-uniform density distribution of Sc-CO₂ leads to varying degrees of volume expansion or shrinkage, influencing fluid flow velocities within the fractures. This study integrates heat transfer and fluid leak-off models into the Eulerian-Eulerian two-fluid framework to systematically investigate the collective impacts of Sc-CO₂'s density, viscosity, and density-induced volumetric alterations on the proppant transport process under varied pumping… More >

Tiangang Lan¹, Mengyuan Ma¹, Shifeng Lu¹, Ling Xu^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.29, No.1, pp. 1-1, 2024, DOI:10.32604/icces.2024.010867

Abstract Natural loess is a kind of kaolin wind-deposited soil.Thedifferent layers of loess experienced different overburden pressures and wetting-drying cycles, resulting in different water retention behaviors.The axis translation technique and the vapor equilibrium technique to determine the water retention behaviorof the three different sediment depth natural loess during drying and wettingprocess. In addition, the microstructure evolution experienced wetting and drying cycles also characterized by mercury intrusion porosimetry. The saturation and air entry value increased with the sediment depth increased because deeper sediment depth means lower initial void ratio. Thewaterretentioncurveshowsthatthereisalmost nohysteresis observed around the naturalsuction,and in relatively… More >

Zhenshuai Wan^1,2,*, Longwang Yue², Yanfeng Wang², Pu Zhao²

CMES-Computer Modeling in Engineering & Sciences, Vol.141, No.2, pp. 1047-1065, 2024, DOI:10.32604/cmes.2024.053773 - 27 September 2024

Abstract Hydraulic actuators are highly nonlinear when they are subjected to different types of model uncertainties and dynamic disturbances. These unfavorable factors adversely affect the control performance of the hydraulic actuator. Although various control methods have been employed to improve the tracking precision of the dynamic system, optimizing and adjusting control gain to mitigate the hydraulic actuator model uncertainties remains elusive. This study presents an adaptive back-stepping sliding mode controller (ABSMC) to enhance the trajectory tracking precision, where the virtual control law is constructed to replace the position error. The adaptive control theory is introduced in More >

Hong Dong¹, Xiding Gao^2,*, Xinqi Zhang¹, Qian Wang^1,3, Haipeng Xu¹, Binrui Wang², Chengguo Gao¹, Kaiwen Luo², Hengyi Jiang²

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.9, pp. 1971-1991, 2024, DOI:10.32604/fdmp.2024.049406 - 23 August 2024

Abstract CO₂ pre-injection during hydraulic fracturing is an important method for the development of medium to deep heavy oil reservoirs. It reduces the interfacial tension and viscosity of crude oil, enhances its flowability, maintains reservoir pressure, and increases reservoir drainage capacity. Taking the Badaowan Formation as an example, in this study a detailed three-dimensional geomechanical model based on static data from well logging interpretations is elaborated, which can take into account both vertical and horizontal geological variations and mechanical characteristics. A comprehensive analysis of the impact of key construction parameters on Pre-CO₂ based fracturing (such as cluster More >