bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coupled Wellbore-Reservoir-Geomechanics Modeling of Parent Well Depletion-Induced Stress Evolutions and Their Potential Impact on Infill Well Fracturing
Authors: Guo Xuyang , Jin Yan , Chen Mian , Song Hongwei 
Published: August 2024

ABSTRACT:
Parent well depletion in shale oil reservoirs leads to in-situ stress changes, consequently altering infill well fracturing quality. Parent well depletion-induced responses are often modeled by coupled flow and geomechanics where the effect of wellbore flow is not thoroughly considered. This study introduces a coupled wellbore-reservoir-geomechanics model considering the wellbore flow. Both system responses in the reservoir and in the wellbore are quantified. Results show that considering the wellbore flow can improve the comprehensiveness of the modeling scheme. The non-uniform productivity distribution among perforations and its relationship with the coupled flow and geomechanical response are documented. The effect of wellbore flow becomes greater as the scale of the problem increases, and the synthetic field scenario has a more significant wellbore flow impact on geomechanics. This work proposes a coupled wellbore-reservoir-geomechanics model that considers the mass conservation and fluid flow in both the wellbore and the reservoir. It specifically quantifies the effect of the oil rate competition between parent well fracture clusters.

1. INTRODUCTION
Infill well drilling and hydraulic fracturing have become a key strategy in the development of shale oil reservoirs since the combination of parent and infill wells can help to improve the estimated ultimate recovery (Lindsay et al. 2018). Infill wells are often drilled and completed later than parent wells, and the pressure and in-situ stress fields for infill wells fracturing can be rather different from parent wells. Since the hydraulic fracturing quality is often governed by the pressure and stress states, the reliable and accurate prediction and modeling of the stress state changes in infill zones and at candidate infill well drilling locations become very relevant (Kurtoglu and Salman 2015; Zhi et al. 2021 Chen et al. 2021). Pressure drops, stress magnitude changes, and stress orientation changes in infill zones should all be evaluated before infill well completion designs are made. If infill well fracturing parameters are not carefully determined, negative outcomes such as productivity decrease, well control problems, casing damage, and loss of wells can be obtained (Morales et al. 2016; Jacobs 2017; Rainbolt and Esco 2018).
Geomechanical Practices in Developing Open-Pit Slopes at Kinross Gold
Authors: Ran Jerry J. 
Published: August 2024

ABSTRACT:
Open-pit slope instabilities may lead to personnel injuries and/or equipment damages in some cases. However, in most cases, these events require mitigation measures like step-outs, unloading, buttressing and local slope flattening with potential impact on mine production in short or long term.
Noncompliance with slope design criteria, which may be a contributing factor in slope instability, potentially creates an unsafe working environment and has a negative impact on mine performance.
Achieving an optimized balance between open-pit slope performance and financial objectives is the goal of many corporate risk management systems in the mining industry. The basis for a practical and achievable slope design is a reliable geomechanical model. Application of this model and slope design acceptance criteria leads to selection of slope design parameters that derive from various geomechanical analyses and numerical modeling, and this process reflects the risk tolerance level of the project or operation owner. In the mine production stage, i.e., implementation of the slope design, operational controls in drilling and blasting, bench face cleaning and visual and instrumentation monitoring play a key role in achieving the recommended slope design.
Building the geomechanical model and subsequent slope design normally start with data collection by launching a drilling and testing program with or without outcrop or exposed bench mapping. As mining progresses, the initial slope design is updated based on actual slope performance and data collected through ongoing programs, for instance, physical and image mapping.
Hydrogeological input to slope stability analysis is critical in many cases particularly in weak rock masses. Input data normally come from non-mining functional groups in early stages of a project or mine operation. This practice may create slope performance issues in the design implementation phase.
This presentation discusses topics described above with examples from Kinross mines. The intention is to draw discussions from peers, initiate ideas in research and development, and help practitioners learn from industry cases.
Evolution of Proppant Embedment and its Impact on Shale Permeability
Authors: Qian Sijin , Lu Mingyuan , Li Jimmy Xuekai , Huang Yixiao , Chen Zhongwei , Shen Luming 
Published: August 2024

ABSTRACT:
Hydraulic fracturing is important for modern gas extraction. However, the proppant embedment affects gas recovery significantly. This study investigates the impact of proppant embedment on permeability over time in shale reservoirs. The study utilized a series of experiments to determine the impact of proppant embedment on permeability over time and designed new methods to induce long-term proppant embedment in proppant-supported fractures. The results showed that the permeability loss after 8 weeks of compression ranges from 4.38 to 6.44 mD, and the percentage ranges from 6.74 to 8.89%. The study also found that the average proppant embedment depth reaches 87.96 μm after 8 weeks compression. The correlation between embedment depth and compression day can be suitably modeled with a logarithmic function. These findings can help optimize production in shale reservoirs by providing a better understanding of proppant embedment and its impact on gas recovery.

1. INTRODUCTION
Hydraulic fracturing is a vital technique to increase the gas production from unconventional reservoirs, which are characterized by low permeability and porosity such as shale and coal seam. This technique creates a network of fractures in the formation, which increases the production rate of natural gas. Due to the high closing stress underground, proppants, typically sands and ceramic grains, are also mixed with the fracking fluid and pumped into the fracture to prevent the fracture from closing and allow gas to pass through the fracture continually. However, the fracture still trends to close over time due to some behaviors in the formation such as proppant flow back (Chuprakov et al., 2020; Hu et al., 2014; Murphey et al., 1989; Parker et al., 1999), proppant fines generation and migration (Kong et al., 2023; Pan et al., 2018; Wang et al., 2020), proppant crush resistance (Liang et al., 2015; Liang et al., 2016; Stephens et al., 2006; Zheng et al., 2018) and proppant embedment (Ghanizadeh et al., 2016; Huang et al., 2019; Liu et al., 2021).
Solids Production Geomechanical Evaluation in a Fractured/Vuggy Carbonate Reservoir from Abu Dhabi Offshore Field: Postmortem Analysis and Advanced Finite Element Simulations
Authors: Pourpak Hamid , Su Kun , Bikong Christian , Rammal Hadi , Bigno Yann , Xi Guifen , Kheidri Hamza , Bere Adam , Kato Jun 
Published: August 2024

ABSTRACT:
Solids production can happen in carbonate rocks even with high strength matrix, because of presence of natural fractures and vuggy or weak zones. Solids production is known to be a common factor in many oil and gas producing wells in carbonate reservoirs both at the early production period but also in later life of a reservoir under depleted conditions. In this paper, we present a real case study performed on a carbonate reservoir located in Abu Dhabi Offshore Field. The production of carbonate debris was observed in a 900m horizontal well completed as barefoot in Arab limestone formation which is a gas bearing reservoir on the area of study and is characterized by natural fractures and weak zones. Anomalous well head flowing pressure (WHFP) behavior and progressive reduce of gas rate were observed with choke fully open and the choke was found partially plugged by debris of centimetric size. The study goal was to investigate whether the solids production experienced was a result of the geomechanical behavior of the rock and fractures during production and to propose mitigations for future wells in terms of completion option and critical drawdown pressure (CDP). This solids production modeling study gave helpful insights regarding the mechanisms of solid production in open hole and cased/perforated wells for the studied carbonate formation. It could also guide the choice of completion and help the solid management decisions for the development of such carbonate reservoirs.

1. INTRODUCTION
Solids production can happen from poorly consolidated carbonate rocks or even in high strength but naturally fractured vuggy carbonates including weak zones. The risk of solids production from carbonate rocks or mitigations of the risks have been discussed in recent literatures (Asadi et al, 2017, AL-Aamri et al, 2020, Ghazali et al, 2020). Solid production is a common factor in many wells in carbonates rocks (oil and gas) during production stages and especially in the later life of a reservoir under depletion conditions (Asadi et al, 2017). Clusters of cemented grains of the formation can be produced together with oil, gas, and water and these could have highly damaging effects on completion equipment, tubing, pipes, valves, and other facilities. Solids production is generally caused by mechanical failure of near wellbore formations due to effective stresses acting on borehole walls, and perforations under drawdown and well flowing conditions exceeding the mechanical strength of reservoir rocks (Asadi et al, 2017).
Seismic Risk Management Practices at Vale's Sudbury Operations
Authors: Yao M. , Landry D. 
Published: August 2024

ABSTRACT:
Vale Base Metals has been operating many underground mines in the Sudbury Basin for over a century and all mines have experienced a significant increase in the number of major seismic events over the last decade. Various mitigation strategies have been developed at Vale's North Atlantic Operations in Ontario to manage and control the risks associated with seismicity and rockbursts. The mines have seen a significant increase in the number of large seismic events, but the overall trend of rockbursts is decreasing. This paper will focus on Seismic Risk Management Strategies developed over the last decade, including both strategic and tactical control measures. Examples will be given in the paper to demonstrate the effectiveness of control measures over the last decade. Recent developments in Seismic Hazard Assessment for burst prone ground conditions are also presented in this paper. Although the strategies presented in this paper can be applied to other deep hard rock underground mine operations that face similar challenges with burst-prone ground conditions, they should be applied with caution and tailored for site specific conditions.

1. INTRODUCTION
Vale Base Metals has operated several underground mines in Sudbury for over a century, and currently five mines are active (Coleman, Creighton, Copper Cliff, Garson, and Totten Mines). Numerous mining methods have been employed including cut and fill, post pillar cut and fill, and sub-level caving, however, currently the primary mining method employed is open stoping.
The primary rock mechanics challenge at these operations is seismicity and rock bursting. Figure 1 shows a recent rockburst at one of the mines which was associated with a large seismic event.
Seismicity has been observed to be primarily linked with:
• Late stage of extraction: sill and diminishing pillars
• Brittle and high strength rocks (UCShost &gt; 200 MPa)
• Mining depths between 1.5 and 2.5 km below surface
• Lack of confinement due to higher extraction ratio
• Presence of seismically active geological structures
A Seismic Risk Management Plan is an important element at any seismically active mine and is also a legal requirement in some mining jurisdictions. The following main items are key requirements:
• Responsibilities
• Microseismic Monitoring & Data Analysis
• Seismic Hazard Assessments
• Hazard Mitigation Plans/Strategies
• Training
This paper will focus on two key requirements described above: Hazard Mitigation Strategies and Seismic Hazard Assessments.
3DEC Modelling Exploration of Residual Stress Mechanisms
Authors: Trzop M. , Corkum A. G. 
Published: August 2024

ABSTRACT:
Residual stress exists as a natural phenomenon found in situ and as a by-product of creation for certain man-made materials. An early implication for residual stresses was illustrated with Prince Rupert's drops where, due to induced compressive residual stress magnitudes the material strength is effectively increased. Residual stress exists in a state of equilibrium with their own internal forces, and as a result are often omitted from stress considerations for design but we believe that these stresses may impact the mechanical behaviour. The purpose of this study was to include residual stresses in modelled specimens of rock to investigate the potential for damage to be present as a result of their redistribution. Residual stresses were formed under load, and once present the specimen was unloaded and damage was quantified through the number of broken subcontacts within the model. Compression tests were then performed on the damaged specimens to investigate the presence of crack closure strains as a result of the produced damage. It was shown that residual stresses can produce damage, and such damage also can produce crack closure strains.

1. INTRODUCTION
Residual stresses exist as a natural phenomenon found in situ and as a byproduct of formation for certain man-made materials. The state of residual stress contains both compressive and tensile stress magnitudes which allows for the residual stress field to reach a state of equilibrium independently from external pressures. As a result of this self-equilibrating nature, residual stresses are often overlooked as they exist separately from both in situ stress and excavation-induced stresses. However, if a residual stress field is disturbed (e.g., fracture formation), the stresses will mobilize in an attempt to reach a new state of equilibrium and will accompany a measurable strain. Although these stresses exist separately from other common stresses, it is important to understand their existence as they may have consequential impacts if not properly understood. An example of this in steel is the case of the split I-beam (Nau, 2015) where due to casting, residual stresses were created within the beam. Once fully hardened the beam was cut at an angle on both ends which disturbed the state of equilibrium and caused a redistribution of the residual stresses. As a result of their redistribution, the I-beam fully split through the web which then destroyed the beam.
A Play-Agnostic Thermo-Poro-Hydro-Mechanical Approximation for Hydraulic Fracture Initiation: Insights on Stress Distortions Between the Wellbore and a Perforation Tunnel
Authors: Bouabdallah Nassim , Michael Andreas 
Published: August 2024

ABSTRACT:
Predicting near-wellbore hydraulic fracture (HF) orientation is crucial for designing stimulation treatments. This work proposes a physics-based approach to determine the orientation of HF initiation considering formation breakdown pressure (FBP) and key geomechanical parameters. A novel closed-form pseudo three-dimensional (3D) approximation captures thermal, poroelastic, hydraulic, and mechanical effects (TPHM), visualizing the stress distortion at the intersection between the wellbore and a perforation tunnel. While specific formations like the Bakken Shale may present unique challenges, the proposed approach transcends such limitations. The play-agnostic TPHM model allows the identification of favorable conditions for transverse HFs across diverse geological settings and wellbore pressure regimes. This empowers engineers to manipulate controllable parameters, such as wellbore pressure and perforation design, to optimize stimulation treatments in various formations, ultimately maximizing well productivity. By promoting favorable HF initiation and early propagation, this approach has the potential to reduce completion issues, enhance well performance, and contribute to a more efficient and sustainable approach to the development of unconventional reservoirs.

1. INTRODUCTION
A number of analytical attempts were made to describe HF initiation from perforated wells. Common to all are two-dimensional (2D) analytical expressions of elasticity relationships, solving the stresses on the wellbore walls. While these models are elegant closed-form expressions of the HF initiation and are particularly useful in practical HF design, they do not consider the presence of perforation tunnels intersecting the wellbore.
Economides et al. (1989) described the stimulation of horizontal wells and the criteria for the decision between longitudinal (axial to the wellbore) and transverse (orthogonal to the wellbore) HFs, as displayed on Fig. 1. Multiple transverse-HF initiations from horizontal wells is the desired outcome of modern-day reservoir stimulation operations. This is despite that in a transverse HF, the flow regime from the reservoir into the HF is linear, while the flow inside the HF is radial, resulting in a pressure drop that contributes to the well's skin. Being able to "stack" multiple transverse HFs near each other in shales will outperform a gigantic longitudinal HF, which is the inadvertent outcome of multiple longitudinal-HF initiations from a horizontal well's lateral.
Correlation of Static and Dynamic Mechanical Properties of Australian Sedimentary Rocks
Authors: Li Jimmy Xuekai , Chen Shuai , Qin Sijin , Flottmann Thomas , Huang Yixiao , Saber Erfan , Chen Zhongwei 
Published: August 2024

ABSTRACT:
This paper presents a comprehensive analysis of the correlation between static and dynamic mechanical properties of sedimentary rocks from Australian basins. By leveraging both empirical and machine learning techniques, we provide valuable insights into the predictive capabilities of different methodologies and identify the most effective approaches for capturing the intricate relationships within the dataset. The results of our study reveal that several machine learning methods consistently outperform empirical approaches, yielding lower error values and providing more accurate predictions of the correlation between static and dynamic properties. Furthermore, we rank these machine learning methods based on their respective error values, offering insights into the relative performance of each algorithm. Our findings not only advance our understanding of sedimentary rock mechanics but also offer practical recommendations for improving reservoir characterization, enhancing geotechnical assessments, and optimizing engineering design.

1. INTRODUCTION
Sedimentary rocks are integral components of the Earth's crust, encompassing a vast array of lithological compositions, depositional environments, and geologic histories (Miall, 2013; Milliken, 2014). Their mechanical properties play a critical role in various engineering and geotechnical applications, including reservoir characterization, wellbore stability assessment, and underground mining design (Abdollahipour et al., 2019; Ghassemi, 2012; Li et al., 2022; Li et al., 2023; Zhong et al., 2021). Understanding the relationship between the static and dynamic mechanical properties of sedimentary rocks is fundamental for accurately predicting their behavior under different loading conditions and is also crucial for interpreting subsurface geology, predicting reservoir behavior, and designing resilient infrastructure (Chang et al., 2006; Sone & Zoback, 2013; Wang et al., 2016).
The Australian continent hosts a diverse range of sedimentary basins, each with unique depositional settings and rock types (Huston et al., 2016; Jaireth et al., 2014; Jaques et al., 2002). These basins offer an excellent opportunity to investigate the correlation between static and dynamic mechanical properties across different geological contexts. Despite the significance of such correlations, comprehensive studies addressing this relationship in the Australian sedimentary basins are limited.
Generation of Micro-Fracture Clouds in Rocks: Mechanisms and Applications
Authors: Mutlu U. , Boitnott G. , Lisjak A. , Mahabadi O. , Sherizadeh T. , Guner D. , Nowak S. , Ghassemi A. 
Published: August 2024

ABSTRACT:
Volume increasing or decreasing processes in rocks can lead to inter or intragranular fractures in subsurface formations. The volume change can be caused by chemical reactions involving fluid, reactive transport, and coupling with the mechanical deformation of the grains. Depending on stress, material properties and coupled thermo-hydro-mechanical-chemical (THMC) conditions, grain scale fractures may propagate and coalesce, forming a cloud of well-connected fracture networks. The mechanisms responsible for propagation, coalescence and inhibition of cloud fractures are not well known. In this study, we review coupled micro-fracture network generation mechanisms as published in the literature and observed in field, experiments, and models. We then introduce simple (decoupled or weakly coupled) models within the framework of analytical and hybrid finite-discrete element models (FDEM). We discuss key parameters that promote (or limit) the generation of micro-fracture clouds under in-situ conditions. Based on the review of literature and preliminary model results, we discuss the implications of micro-fracture generation mechanisms on subsurface storage, hydrogen exploration/production and super-hot supercritical geothermal technologies.

1. INTRODUCTION
Rock deformation and fracturing characteristics under high temperature and pressure (HTHP) conditions are of fundamental significance to emerging subsurface engineering technologies such as super-hot supercritical thermal resources, hydrogen and CO2 storage, and geologic hydrogen production. To unlock the full potential of these applications, it is important to fundamentally understand the fracture initiation, propagation, coalescence and resulting permeability alteration processes and be able to model them at different scales (grain to wellbore to reservoir scale) within the framework of Thermo-Hydro-Mechanical-Chemical (THMC) coupled HTHP systems.
For example, serpentinization is a THMC coupled process that occurs when mafic and ultra-mafic rocks come in to contact with water at specific pressure-temperature conditions to produce hydrogen. This reaction can lead to a significant volume increase, swelling pressures and associated micro-fracture clouds: which in turn can generate additional permeability pathways for flow. Continuous flow of water and mineralization can lead to favorable conditions for a self-driven micro-fracture network, as this process can repeat in a loop: creating a progressive change in host rock permeability.