Yi Song¹, Zheyu Hu^2,*, Cheng Shen¹, Lan Ren², Xingwu Guo¹, Ran Lin², Kun Wang³, Zhiyong Zhao⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.3, pp. 609-624, 2024, DOI:10.32604/fdmp.2023.030521

Abstract Deep shale gas reserves that have been fractured typically have many relatively close perforation holes. Due to the proximity of each fracture during the formation of the fracture network, there is significant stress interference, which results in uneven fracture propagation. It is common practice to use “balls” to temporarily plug fracture openings in order to lessen liquid intake and achieve uniform propagation in each cluster. In this study, a diameter optimization model is introduced for these plugging balls based on a multi-cluster fracture propagation model and a perforation dynamic abrasion model. This approach relies on proper consideration of the multiphase… More > Graphic Abstract

Yongwei Duan, Zhaopeng Zhu, Hui He^*, Gaoliang Xuan, Xuemeng Yu

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.2, pp. 349-364, 2024, DOI:10.32604/fdmp.2023.042659

Abstract The gas-water two-phase flow occurring as a result of fracturing fluid flowback phenomena is known to impact significantly the productivity of shale gas well. In this work, this two-phase flow has been simulated in the framework of a hybrid approach partially relying on the embedded discrete fracture model (EDFM). This model assumes the region outside the stimulated reservoir volume (SRV) as a single-medium while the SRV region itself is described using a double-medium strategy which can account for the fluid exchange between the matrix and the micro-fractures. The shale gas adsorption, desorption, diffusion, gas slippage effect, fracture stress sensitivity, and… More >

Surajudeen Sikiru^1,*, Hassan Soleimani², Amir Rostami¹, Mohammed Falalu Hamza^1,3, Lukmon Owolabi Afolabi⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.1, pp. 31-44, 2024, DOI:10.32604/fdmp.2023.029281

Abstract Determining the adsorption of shale gas on complex surfaces remains a challenge in molecular simulation studies. Difficulties essentially stem from the need to create a realistic shale structure model in terms of mineral heterogeneity and multiplicity. Moreover, precise characterization of the competitive adsorption of hydrogen and methane in shale generally requires the experimental determination of the related adsorptive capacity. In this study, the adsorption of adsorbates, methane (CH₄), and hydrogen (H₂) on heterogeneous shale surface models of Kaolinite, Orthoclase, Muscovite, Mica, C₆₀, and Butane has been simulated in the frame of a molecular dynamic’s numerical technique. The results show that… More >

Linjuan Zeng¹, Daogang Cai¹, Yunhai Zhao^1,*, Changqing Ye¹, Chengcheng Luo²

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.11, pp. 2813-2825, 2023, DOI:10.32604/fdmp.2023.026190

Abstract The flow behavior of shale gas horizontal wells is relatively complex, and this should be regarded as the main reason for which conventional pipe flow models are not suitable to describe the related dynamics. In this study, numerical simulations have been conducted to determine the gas-liquid distribution in these wells. In particular, using the measured flow pressure data related to 97 groups of shale gas wells as a basis, 9 distinct pipe flow models have been assessed, and the models displaying a high calculation accuracy for different water-gas ratio (WGR) ranges have been identified. The results show that: (1) The… More >

Bin Li^*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.10, pp. 2729-2748, 2023, DOI:10.32604/fdmp.2023.029649

Abstract In order to overcome the deficiencies of current methods for the prediction of the productivity of shale gas horizontal wells after fracturing, a new sophisticated approach is proposed in this study. This new model stems from the combination several techniques, namely, artificial neural network (ANN), particle swarm optimization (PSO), Imperialist Competitive Algorithms (ICA), and Ant Clony Optimization (ACO). These are properly implemented by using the geological and engineering parameters collected from 317 wells. The results show that the optimum PSO-ANN model has a high accuracy, obtaining a R² of 0.847 on the testing. The partial dependence plots (PDP) indicate that… More >

Qing Wang^*, Haige Wang, Hongchun Huang, Lubin Zhuo, Guodong Ji

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.10, pp. 2569-2578, 2023, DOI:10.32604/fdmp.2023.025349

Abstract Sticking is the most serious cause of failure in complex drilling operations. In the present work a novel “early warning” method based on an artificial intelligence algorithm is proposed to overcome some of the known problems associated with existing sticking-identification technologies. The method is tested against a practical case study (Southern Sichuan shale gas drilling operations). It is shown that the twelve sets of sticking fault diagnostic results obtained from a simulation are all consistent with the actual downhole state; furthermore, the results from four groups of verification samples are also consistent with the actual downhole state. This shows that… More >

Jialuo Rong^1,2, Shuixiang Xie^3,4, Huijing Geng⁵, Hao Hu^1,2, Shanfa Tang^1,2,*, Yuanpeng Cheng^1,2,*

Energy Engineering, Vol.120, No.8, pp. 1899-1917, 2023, DOI:10.32604/ee.2023.027650

Abstract Due to its extensive use in shale gas exploration and development, oil-based drilling fluids generate large amounts of oil-bearing drill cuttings during the drilling process. The large amount of oil-bearing drill cuttings generated during the drilling process can lead to serious secondary contamination. In this study, a wetting agent FSC-6 with good hydrophobic and oleophobic properties was synthesized to construct an efficient oil removal system. For the first time, the mechanism of this system was analyzed by using the theory of adhesion function, interfacial tension and wettability. At the same time, a combined acoustic-chemical treatment process was applied to the… More >

Zhiyuan Yao^1,2,3, Jing Sun^1,2,3,*, Dehua Liu^1,2,3

Energy Engineering, Vol.120, No.8, pp. 1853-1866, 2023, DOI:10.32604/ee.2023.025846

Abstract Shale gas reservoirs have poor physical properties and a large number of micro-nano pores have been developed. Shale gas wells have no natural productivity and need fracturing reconstruction measures to put into production. However, the fracturing fluid will enter the reservoir space of shale matrix after fracturing and affect the production of shale gas. At present, there is no consensus on the influence of fracturing fluid retention on gas well production. Based on this, the paper adopts gas molecular transport analyzer to carry out experimental research on the influence of fracturing fluid on shale gas diffusion law after entering matrix… More >

Hongsha Xiao¹, Ruihan Zhang^2,*, Man Chen¹, Cui Jing¹, Shangjun Gao¹, Chao Chen¹, Huiyan Zhao¹, Xin Huang^2,*, Bo Kang³

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.7, pp. 1803-1815, 2023, DOI:10.32604/fdmp.2023.026143

Abstract The production performances of a well with a shale gas reservoir displaying a complex fracture network are simulated. In particular, a micro-seismic cloud diagram is used to describe the fracture network, and accordingly, a production model is introduced based on a multi-scale flow mechanism. A finite volume method is then exploited for the integration of the model equations. The effects of apparent permeability, conductivity, Langmuir volume, and bottom hole pressure on gas well production are studied accordingly. The simulation results show that ignoring the micro-scale flow mechanism of the shale gas leads to underestimating the well gas production. It is… More > Graphic Abstract

Shiyu Miao^1,2,3, Xiao Liu⁴, Xiaoya Feng⁶, Haowen Shi^1,2,3, Wei Luo^1,2,3,*, Peng Liu⁵

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.7, pp. 1735-1751, 2023, DOI:10.32604/fdmp.2023.025681

Abstract At present, the optimization of the plunger mechanism is shale gas wells is mostly based on empirical methods, which lack a relevant rationale and often are not able to deal with the quick variations experienced by the production parameters of shale gas wells in comparison to conventional gas wells. In order to mitigate this issue, in the present work, a model is proposed to loosely couple the dynamics of gas inflow into shale gas wells with the dynamics of the liquid inflow. Starting from the flow law that accounts for the four stages of movement of the plunger, a dynamic… More > Graphic Abstract