Key Takeaways & Executive Findings
- •• The alternative hydrofracturing scheme yields the largest fracturing area compared to synchronous and sequential schemes. • Synchronous fracturing produces a significantly smaller fracturing area, indicating a stronger stress-shadow effect. • A novel concept of 'stress-blind area' is introduced to quantify mechanical disturbance between adjacent wells. • The hybrid finite element-discrete element method effectively models 3D fracture propagation and reorientation at engineering scale.
Abstract
Multistage fracturing technology has been used to enhance tight hydrocarbon resource recovery. Determining the proper well spacing and fracturing strategy is crucial for generating a complex fracture network that facilitates oil and gas flow in reservoirs. The stress-shadow effect that occurs between multiple wells significantly affects the development of fracture networks in reservoirs. However, the quantification of the stress-shadow effect and its influence on fracture networks has not been satisfactorily resolved because of the difficulties in detecting and identifying fracture propagation and reorientation in reservoirs. In this study, based on the geological information from the Shengli oilfield, we applied a hybrid finite element-discrete element method to analyze engineering-scale three-dimensional fracture propagation and reorientation by altering well spacings and fracturing strategies. The results indicate that the fracturing area generated by the synchronous fracturing scheme is much smaller than those generated by the sequential and alternative schemes. An alternative hydrofracturing scheme is optimal with respect to fracturing area. The stress-blind area was defined to quantify the mechanical disturbance between adjacent wells. Our study improves the understanding of the effect of fracturing schemes on fracture networks and the impact of independent factors contributing to stress-shadow effects.
1. Introduction
The exploitation and development of terrestrial and marine unconventional oil and gas in shale reservoirs have attracted increasing attention [1]. Innovative horizontal and vertical well-fracturing techniques have recently been developed to increase unconventional terrestrial marine gas and oil production [2]. The design and layout of stereo wells, which are mostly determined by geological parameters, are essential for extracting unconventional hydrocarbon sources [3]. A single fracturing well cannot satisfy reasonable production requirements of thick and block reservoirs; it results in low levels of oil and gas reservoir exploitation, low oil-recovery rates, and low sweep efficiency of water driving. The key to achieving a reasonable and successful utilization of this type of reservoir is the establishment of an optimized stereo well pattern [4].
Currently, China has a superb stereo well pattern technology that is widely used in Daqing, Shengli, Changqing, and other oil fields. This technology has evolved with the development of directional and horizontal well technologies. Stereo well pattern system encompasses various concepts that primarily refer to a design that integrates vertical and horizontal wells. This configuration establishes fracture networks that extend along horizontal wells. Additionally, vertical wells are fractured to enhance hydrocarbon contact in regions inadequately covered by horizontal wells. Developers have efficiently extracted oil and gas from stereo well patterns in the Permian Basin, spanning Texas and New Mexico in the USA. The steam-assisted gravity drainage technique, a renowned combined production method, involves fracturing upper vertical wells, followed by steam injection, and oil extraction from lower horizontal wells. The steam, introduced post-fracturing, heats the oil formation, facilitating upward and lateral movement to create a steam chamber. The resultant heat reduces the viscosity of crude oil and condensate, which then flow into the lower horizontal wells under the influence of gravity for extraction. Fracture disturbance inevitably arises regardless of the method used.
Loading authentic research manuscript (Pages 1–5)...
JU Yang, LI Yang, YANG Yongming, WANG Yongliang (2025). Reorientation of hydraulic fractures and stress-shadow effect in double-well fracturing of hydrocarbon reservoirs: 3D numerical model and analysis. SinoTechIntel Verified Research. https://doi.org/10.1016/j.ijmst.2025.02.011
Research & Educational Purpose Only:The translations, structured abstracts, analytical annotations, and data reports provided by SinoTechIntel are intended exclusively for academic research, internal corporate R&D, and educational benchmarking. They do not constitute formal engineering, chemical safety, legal, or professional advice.
Copyright & Intellectual Property Notice: Original copyright of the underlying source articles and experimental data remains with the respective authors, institutions, and original publishing journals. SinoTechIntel claims intellectual property only over its proprietary translations, analytical syntheses, and AEO structured enhancements in accordance with international fair use and academic citation principles.
Frequently Asked Questions
What is the stress-shadow effect in hydraulic fracturing?
The stress-shadow effect refers to the alteration of in-situ stress around a hydraulic fracture, which can influence the propagation of nearby fractures. In multi-well fracturing, the stress shadow from one well can impede or reorient fractures from adjacent wells, affecting the overall fracture network complexity and reservoir stimulation efficiency.
Which fracturing scheme is most effective for maximizing fracture area?
According to the study, the alternative hydrofracturing scheme (alternating injection between wells) produces the largest fracturing area compared to synchronous (simultaneous) and sequential (one after another) schemes. This is because it mitigates the stress-shadow effect, allowing more uniform fracture growth.
How was the stress-shadow effect quantified in this research?
The researchers introduced the concept of 'stress-blind area' to quantify the mechanical disturbance between adjacent wells. This area represents the region where the stress shadow significantly alters the local stress state, affecting fracture propagation. The size of this area varies with well spacing and fracturing scheme.
What numerical method was used in this study?
The study employed a hybrid finite element-discrete element method (FEM-DEM) to simulate three-dimensional fracture propagation and reorientation at an engineering scale. This approach captures both the continuum behavior of the rock and the discrete nature of fractures.
What are the practical implications of this research for hydraulic fracturing design?
The findings provide insights into optimizing well spacing and fracturing strategies to enhance fracture network complexity. By understanding the stress-shadow effect, engineers can choose alternative fracturing schemes and appropriate well spacing to maximize stimulated reservoir volume, improving hydrocarbon recovery.
Related Technical Papers & Translations
A Novel Approach for Enhanced Brain Tumor Segmentation Using Multimodal MRI and Deep Learning
Brain tumor segmentation from multimodal MRI is crucial for diagnosis and treatment planning. In this study, we propose a novel deep learning framework that integrates structural and functional imaging modalities to improve segmentation accuracy. Our method employs a multi-scale attention mechanism and a hybrid loss function to handle class imbalance and boundary ambiguity. Evaluated on the BraTS benchmark, our approach achieves state-of-the-art performance, with Dice scores of 0.91, 0.87, and 0.84 for whole tumor, core, and enhancing tumor, respectively. Furthermore, we demonstrate the generalizability of our model across different scanners and protocols. Our findings suggest that the proposed method can significantly aid clinical decision-making and surgical planning.
Investigation of coupled acoustic and electrical responses and early warning approaches during re-loading of damaged coal
Initial damage from engineering disturbances in deep coal mining degrades mechanical properties and heightens dynamic-hazard risks, challenging conventional monitoring. This study probes the coupled acoustic-electrical responses of initially damaged coal under reloading and develops a multi-parameter, multi-level dynamic integrated early-warning model. Using a true-triaxial Split Hopkinson Pressure Bar (SHPB) system, we prepared specimens with graded damage by varying static deviatoric stresses and dynamic impacts. Uniaxial compression reloading was conducted with synchronous acoustic emission (AE) and resistivity monitoring. Joint time-domain responses of force, acoustics, and electricity delineated distinct loading stages. Time-frequency features were extracted via Fourier and wavelet transforms; crack architecture was quantified by 3D AE localization and fractal-dimension analysis. Initial damage markedly reduced load-bearing capacity. Resistivity decreased sharply with increasing deviatoric stress, while cumulative AE counts increased strongly. The AE spectrum evolved from bimodal to broadband with low- and high-frequency enhancement. The resistivity spectrum showed progressive bandwidth broadening, energy amplification, and high-frequency advancement. The AE spatial fractal dimension rose significantly during compaction. An integrated warning system combining multiscale entropy fusion, Temporal Convolutional Network (TCN)-Transformer forecasting, recurrence-network analysis, and a Bayesian framework yielded a 28.4 s lead time, offering a theoretical basis and technical pathway for intelligent prevention of dynamic hazards.
Influence of aggregate particle size on fracture behavior and energy evolution of cemented rockfill in the post-peak stage
Cemented rockfill (CRF) combines structural support with sustainable reuse of coal-derived solid waste. This study integrates digital image correlation, acoustic emission monitoring, and finite–discrete element simulations to investigate mechanical behavior, fracture development, and energy evolution of CRF containing 54% aggregate content with three grain-size distributions (5–10, 10–20, and 20–30 mm). Results indicate finer aggregates raise compressive strength and elastic modulus, and increase post-peak softening and residual stiffness. Fracture patterns transition from dominantly unidirectional failure in coarse specimens to pronounced X-shaped conjugate shear in fine specimens, with cracks initiating at boundaries and propagating inward. The proportion of failed joints at comparable strains decreases markedly with finer gradation, reflecting a more homogeneous crack network that enhances post-peak load retention and produces frequent minor stress fluctuations. Energy analyses reveal a coarse > medium > fine ordering in cumulative dissipation; however, finer aggregates delay rapid kinetic and dissipative energy release, promoting slower energy redistribution and improved load resistance. These findings quantify how aggregate gradation controls deformational mechanisms, crack topology, and energy partitioning, and provide design guidance for optimizing aggregate size and cementitious composition to enhance ductility, energy absorption, and structural reliability of CRF in underground engineering.