V. V. Poplygin^1,*, A. Dieng², Min Wang³, Xian Shi³

Energy Engineering, Vol.123, No.7, 2026, DOI:10.32604/ee.2025.074170 - 18 June 2026

Abstract Hydraulic fracturing in carbonate reservoirs presents unique challenges due to their complex pore structures and heterogeneous mechanical properties. This paper explores the application of statistical methods to improve fracture prediction and optimization in carbonate formations. Hydraulic fracturing is actively carried out on these formations. In order to properly plan hydraulic fracturing, it is necessary to identify the main factors affecting oil production after hydraulic fracturing. This study introduces an integrated framework combining information amount theory (IAT) and Gray relational analysis (GRA) to identify and rank the dominant parameters controlling hydraulic fracturing performance in heterogeneous carbonate… More >

Boyun Guo^*

Energy Engineering, Vol.123, No.6, 2026, DOI:10.32604/ee.2026.080366 - 27 May 2026

Abstract It is generally believed that the productivity of oil/gas wells in shale reservoirs increases with the population of hydraulic fractures in the stimulated reservoir volume. The objective of this work is to identify the dominant factors affecting hydraulic fracture population in shale oil/gas reservoirs. A semi-analytical model was first developed to simulate the sequential initiation and simultaneous propagation of hydraulic fractures during fracturing shale gas/oil reservoirs. The semi-analytical model was then coded in the FracPropag computer program for model validation and quick analyses. The sequential initiation and simultaneous propagation of hydraulic fractures predicted by FracPropag… More > Graphic Abstract

Sheng Lei^1,2,3, Guanglong Sheng^1,2,3,*, Hui Zhao^1,2,3

Energy Engineering, Vol.123, No.6, 2026, DOI:10.32604/ee.2025.073788 - 27 May 2026

Abstract Multi-stage fractured horizontal wells are among the most prevalent technologies in contemporary shale oil development. This article provides a comprehensive overview of several prevalent issues by examining pertinent simulation methods applicable to existing fractured horizontal wells. First, traditional methods primarily concentrate on individual stages of fracturing, shut-in, and production. These stages are relatively isolated and lack continuity. Second, the effects of reservoir stimulation vary under different operational conditions. The conventional dual (or multiple) porosity model is overly idealized, while analytical (or semi-analytical) models often struggle to accurately represent actual fracture geometries and internal fracture-grid characteristics,… More > Graphic Abstract

Pujin Wang^1,2,3, Guofa Ji^1,2,3,*, Wenwei Zhao^1,2,3, Liangping Yi⁴

Energy Engineering, Vol.123, No.5, 2026, DOI:10.32604/ee.2026.078171 - 27 April 2026

Abstract In multi-cluster horizontal well fracturing, non-uniform propagation due to inter-cluster interference severely limits the effectiveness of reservoir stimulation. This study employs the discrete lattice method for numerical simulation, investigating the influence of cluster spacing, fracturing fluid injection rate, and horizontal stress difference on fracture propagation morphology by monitoring, in real time, the dynamic changes in flow pressure, flow rate, and fluid intake volume for each cluster. The results indicate that the stress shadow effect is the fundamental cause of non-uniform fracture propagation. Cluster spacing is a key parameter controlling the maximum flow pressure difference between… More >

Huiyong Yu¹, Haifu Li¹, Liwei Zhang¹, Yong Chen¹, Rui Wang¹, Qiyong Xiong¹, Xuyang Guo², Shijie Shen^2,*

Energy Engineering, Vol.123, No.4, 2026, DOI:10.32604/ee.2025.072416 - 27 March 2026

Abstract Re-fracturing horizontal wells is a critical strategy for enhancing recovery from tight oil reservoirs, but its success depends on the evaluation of candidate wells and locations. This process is complicated by production-induced alterations in reservoir pressure and geomechanical responses. This study introduces a workflow to evaluate re-fracturing potential by integrating coupled fluid flow and geomechanical modeling for the production of initial hydraulic fractures. We developed a numerical model that simulates the poroelastic response of a tight oil reservoir to depletion from an initial set of hydraulic fractures. To quantify the re-fracturing potential along the horizontal… More >

Bo Zeng¹, Junfeng Li¹, Liqing Chen¹, Qiyong Gou¹, Hao Luo², Haiyan Zhu², Xuanhe Tang^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.22, No.2, 2026, DOI:10.32604/fdmp.2026.069978 - 04 March 2026

Abstract Deep shale gas reservoirs in the southern Sichuan Basin are typically characterized by significant horizontal stress anisotropy (expressed as stress difference), variable brittleness–ductility in rock mechanics, and strong heterogeneity. These complex geomechanical conditions lead to pronounced differences in hydraulic fracturing outcomes among wells and sections. To investigate hydraulic fracture propagation and fracturing fluid injection behavior under varying geomechanical settings, true triaxial physical simulation tests were performed on 400 × 400 × 400 mm artificial rock samples. The samples were designed with different media properties based on similarity criteria. A sensitivity analysis was conducted to assess… More >

Yang Zhang¹, Xiaoping Yang¹, Yalan Zhang¹, Mingzhe Han¹, Jiayi Sun², Zhengsheng Xia^3,*

FDMP-Fluid Dynamics & Materials Processing, Vol.22, No.1, 2026, DOI:10.32604/fdmp.2026.075388 - 06 February 2026

Abstract Self-suspended proppants, which enable clear-water fracturing, represent a promising new class of materials for reservoir stimulation. Given the economic limitations associated with their exclusive use, this study investigates proppant transport behavior in hybrid systems combining self-suspended proppants with conventional 40/70 mesh quartz sand at various mixing ratios. A dedicated experimental apparatus was developed to replicate field-relevant complex fracture networks, consisting of a main fracture and two branching fractures with different deflection angles. Using this system, sand bank formation and proppant distribution were examined for both conventional quartz sand fracturing and fracturing augmented with self-suspended proppants.… More >

Zhirong Jin^1,*, Xiaorui Hou¹, Yanrong Ge¹, Tiankui Guo², Ming Chen², Shuyi Li², Tianyu Niu²

Energy Engineering, Vol.123, No.2, 2026, DOI:10.32604/ee.2025.070750 - 27 January 2026

Abstract Hydraulic fracturing serves as a critical technology for reservoir stimulation in deep coalbed methane (CBM) development, where the mechanical properties of gangue layers exert a significant control on fracture propagation behavior. To address the unclear mechanisms governing fracture penetration across coal-gangue interfaces, this study employs the Continuum-Discontinuum Element Method (CDEM) to simulate and analyze the vertical propagation of hydraulic fractures initiating within coal seams, based on geomechanical parameters derived from the deep Benxi Formation coal seams in the southeastern Ordos Basin. The investigation systematically examines the influence of geological and operational parameters on cross-interfacial fracture… More >

Li Wang¹, Xuesong Xing¹, Yanan Hou¹, Heng Wen¹, Ying Zhu¹, Jingyu Zi¹, Qingwei Zeng^2,3,*

Energy Engineering, Vol.123, No.2, 2026, DOI:10.32604/ee.2025.068653 - 27 January 2026

Abstract The deep coal reservoir in Linxing-Shenfu block of Ordos Basin is an important part of China’s coalbed methane resources. In the process of reservoir reconstruction, the artificial fracture morphology of coal seam with gangue interaction is significantly different, which affects the efficient development of coalbed methane resources in this area. In this paper, the surface outcrop of Linxing-Shenfu block is selected, and three kinds of interaction modes between gangue and coal seam are set up, including single-component coal rock sample, coal rock sample with different thicknesses of gangue layer and coal rock sample with different… More >

Xia Yan¹, Wei Wang¹, Kai Shen^2,*, Yanqing Feng¹, Junyi Sun¹, Xiaogang Li¹, Wentao Zhu¹, Binbin Shi¹, Guanglong Sheng^2,3

Energy Engineering, Vol.123, No.1, 2026, DOI:10.32604/ee.2025.070360 - 27 December 2025

Abstract In the development of coalbed methane (CBM) reservoirs using multistage fractured horizontal wells, there often exist areas that are either repeatedly stimulated or completely unstimulated between fracturing stages, leading to suboptimal reservoir performance. Currently, there is no well-established method for accurately evaluating the effectiveness of such stimulation. This study introduces, for the first time, the concept of the Fracture Network Bridging Coefficient (FNBC) as a novel metric to assess stimulation performance. By quantitatively coupling the proportions of unstimulated and overstimulated volumes, the FNBC effectively characterizes the connectivity and efficiency of the fracture network. A background… More >