Marija Macenić, Tomislav Kurevija^*, Tin Herbst

Energy Engineering, Vol.123, No.1, 2026, DOI:10.32604/ee.2025.067067 - 27 December 2025

Abstract The increased interest in geothermal energy is evident, along with the exploitation of traditional hydrothermal systems, in the growing research and projects developing around the reuse of already-drilled oil, gas, and exploration wells. The Republic of Croatia has around 4000 wells, however, due to a long period since most of these wells were drilled and completed, there is uncertainty about how many are available for retrofitting as deep-borehole heat exchangers. Nevertheless, as hydrocarbon production decreases, it is expected that the number of wells available for the revitalization and exploitation of geothermal energy will increase. The… More >

Weiyang Xie^1,2, Cheng Chang^1,2, Ziqin Lai^1,2,*, Sha Liu^1,2, Han Xiao^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.6, pp. 1417-1438, 2025, DOI:10.32604/fdmp.2025.060956 - 30 June 2025

Abstract In the context of post-stimulation shale gas wells, the terms “shut-in” and “flowback” refer to two critical phases that occur after hydraulic fracturing (fracking) has been completed. These stages play a crucial role in determining both the well’s initial production performance and its long-term hydrocarbon recovery. By establishing a comprehensive big data analysis platform, the flowback dynamics of over 1000 shale gas wells were analyzed in this work, leading to the development of an index system for evaluating flowback production capacity. Additionally, a shut-in chart was created for wells with different types of post-stimulation fracture More >

Qi Deng¹, Qi Ruan², Bo Zeng¹, Qiang Liu³, Yi Song¹, Shen Cheng¹, Huiying Tang^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.5, pp. 1201-1219, 2025, DOI:10.32604/fdmp.2025.060311 - 30 May 2025

Abstract Over more than a decade of development, medium to deep shale gas reservoirs have faced rapid production declines, making sustained output challenging. To harness remaining reserves effectively, advanced fracturing techniques such as infill drilling are essential. This study develops a complex fracture network model for dual horizontal wells and a four-dimensional in-situ stress evolution model, grounded in elastic porous media theory. These models simulate and analyze the evolution of formation pore pressure and in-situ stress during production. The investigation focuses on the influence of infill well fracturing timing on fracture propagation patterns, individual well productivity, and… More >

Sheng Ju, Jie Liu^*

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.3, pp. 529-542, 2025, DOI:10.32604/fdmp.2024.057535 - 01 April 2025

Abstract As shale gas technology has advanced, the horizontal well fracturing model has seen widespread use, leading to substantial improvements in industrial gas output from shale gas wells. Nevertheless, a swift decline in the productivity of individual wells remains a challenge that must be addressed throughout the development process. In this study, gas wells with two different wellbore trajectory structures are considered, and the OLGA software is exploited to perform transient calculations on various tubing depth models. The results can be articulated as follows. In terms of flow patterns: for the deep well A₁ (upward-buckled), slug flow… More > Graphic Abstract

Xingbin Zhao¹, Neng Yang², Hao Liang³, Mingqiang Wei^2,*, Benteng Ma², Dongling Qiu²

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.11, pp. 2523-2540, 2024, DOI:10.32604/fdmp.2024.052766 - 28 October 2024

Abstract The transient flow testing of ultra-deepwater gas wells is greatly impacted by the low temperatures of seawater encountered over extended distances. This leads to a redistribution of temperature within the wellbore, which in turn influences the flow behavior. To accurately predict such a temperature distribution, in this study a comprehensive model of the flowing temperature and pressure fields is developed. This model is based on principles of fluid mechanics, heat transfer, mass conservation, and energy conservation and relies on the Runge-Kutta method for accurate integration in time of the resulting equations. The analysis includes the… 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 >

Sha Liu^*, Jianfa Wu, Xuefeng Yang, Weiyang Xie, Cheng Chang

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.10, pp. 2301-2321, 2024, DOI:10.32604/fdmp.2024.052454 - 23 September 2024

Abstract The pivotal areas for the extensive and effective exploitation of shale gas in the Southern Sichuan Basin have recently transitioned from mid-deep layers to deep layers. Given challenges such as intricate data analysis, absence of effective assessment methodologies, real-time control strategies, and scarce knowledge of the factors influencing deep gas wells in the so-called flowback stage, a comprehensive study was undertaken on over 160 deep gas wells in Luzhou block utilizing linear flow models and advanced big data analytics techniques. The research results show that: (1) The flowback stage of a deep gas well presents… More > Graphic Abstract

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 - 12 January 2024

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 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 - 14 December 2023

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… 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 - 25 June 2023

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 More >