bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fluid Induced Elemental and Mineralogy Alterations of Caney Shale
Authors: Awejori G. , Xiong F. , Katende A. , Radonjic M. , Whitworth L. , Paronish T. 
Published: September 2022

ABSTRACT:
Studies were conducted on cores and rock cuttings recovered from two wells drilled in Caney shale in the Southern Oklahoma. Mineralogical compositions of these samples were obtained by X-Ray Diffraction (XRD) measurements using two methods of sample preparation: conventional powder (by crushing and grinding of rock fragments) and spray-drying of micronized rock powder method. Microstructure and microanalysis were acquired by Scanning Electron Microscopy/Energy Dispersive Spectroscopy (SEM/EDS). Batch experiments were then conducted using selected rock samples and fracturing fluid whilst deionized water was used as control sample for fluid/rock interaction. These were conducted at 95°C and ambient pressure for various time periods to assess the geochemical reactivity of the Caney shale. The rock samples were subsequently recovered from fluid, dried and analysis repeated using identical XRD and SEM/EDS measurements, following the same conditions.
Preliminary experimental results show rock mineralogical compositions are predominantly quartz with relatively high clay content. The clay minerals are mainly illite. Carbonate content is less than 10% by weight for most samples, with other non-clay minerals pyrite, albite, dolomite, and some apatite. In general, sprayed samples showed more intense peaks and less full width at half maxima (FWHM) relative to conventional rock-powder samples. Post-experimental mineralogical changes were observed in samples with clay portions breaking down to amorphous entities. As expected, dissolution of carbonates (calcite and dolomite) was observed and newly detected dissolution of biogenic micro quartz resulted in formation of amorphous silica.

1.0 INTRODUCTION
Formation of sedimentary rocks involves processes where rock sediments are emplaced with fluids starting interactions that persist over long periods. During the lithification process, sediments and fluids react and attain equilibrium state. This equilibrium is disturbed during drilling, completion, hydraulic fracturing and other operations that involve the introduction of engineered fluids into the subsurface. To return to equilibrium, dissolution and precipitation of minerals may occur. These reactions have implications on the petrophysical properties of the reservoir. Whiles dissolution and precipitation of minerals can enhance porosity and permeability, the reverse can also be true. For example, when acidic fluids are introduced into formations with high carbonate contents, carbonate minerals dissolve into solution thus increasing the porosity and permeability of the formation. In contrast, when alkaline fluids with pH above 11 are introduced into an illite-rich shale formation, the rock-fluid interaction leads to de-flocculation of illite platelets causing substantial increase in clay fines migration, consequently significant reduction in permeability (Salles et al., 2008).
S-Wave Velocity Prediction Based on Probabilistic Neural Network (PNN) and Deep Feed-Forward Neural Networks (DFNN)
Authors: Esmaeilpour S. , Ispas I. 
Published: September 2022

ABSTRACT:
The accuracy of the shear wave travel time prediction affects the overall accuracy of the elastic parameters, and this will have an impact on the reservoir characterization. Rock elastic parameters are critical to alleviate the risks associated with drilling and wellbore stability. This paper establishes the shear wave prediction model based on two artificial intelligence methods (Probabilistic Neural Network (PNN) and Deep Feed-forward Neural Networks (DFNN)) using Wellington oil field data in south central Kansas. Neural networks are potentially superior to linear or multi-linear regressions, and they can be used to model nonlinear functions. These techniques will be used to enhance the high frequency resolution and prediction capability. DFNN uses multiple hidden layers and offers significant advantages in terms of control of training parameters. More data is required to train DFNNs because of the introduction of additional parameters such as weights, but it proves to be a reliable methodology to quantitatively predict the reservoir’s properties by optimizing the parameters such as the number of hidden layers, the nodes in the hidden layers, and the number of iterations required to solve the problem. To validate the neural network’s approach, a number of wells were hidden, and the trained data was used to predict the S-wave velocities in those wells. The validation correlation shows how well the process will work on a new well that has yet to be drilled. The developed model provides an economical and reliable approach for the determination of geomechanical parameters where S-wave travel times are not available.

1. INTRODUCTION
In this study, Probabilistic neural networks (PNNs) were applied to develop an intelligent predictive model for prediction of the shear wave velocity information. PNNs, firstly introduced by McCulloch and Pitts [8], is a mathematical model of biological events used to imitate the capability of biological neural structures with the purpose of designing an intelligent information processing system. An adaptive neural network is a network structure consisting of large number of elemental units, called neurons, organized in input, hidden, and output layers. Any neuron in the network is characterized by some features such as input weights, a threshold, and an activation function. The adjusting weights connect the neurons in different layers, so that a particular input, according to a learning algorithm, leads to a specific target output [8, 9].
Geomechanical Analysis of Some Potential Shale Reservoir Formations in North Sumatra Basin, Indonesia
Authors: Lanin E. S. , Sone H. 
Published: September 2022

ABSTRACT:
Indonesia, as one of the oil and gas producing countries, has potential shale gas and tight oil resources in some of its basins. However, careful assessment of the geomechanical setting is required because most Indonesian basins lie on active tectonic margins, in contrast to most shale play in the U.S, Canada, and China which lie in stable cratonic settings with normal or strike-slip fault regimes. This study aims to analyze the in-situ stress in the potential shale resources of the Baong, Belumai, and Bampo formations in the North Sumatra Basin, Indonesia, and discuss its implication to hydraulic fracturing strategies. Analyses were conducted on the regional and borehole scales. On the regional scale, the earthquake focal mechanism and surface geological features indicate a reverse fault (RF) environment with the maximum horizontal stress (SHmax) in the northeast-southwest (NE-SW) direction. At the borehole scale, analyses were carried out using wireline logs, drilling reports, leak-off test, and hydraulic fracturing data from a pilot hole in the North Sumatra Basin. Borehole stress analysis suggests a near isotropic stress condition in the RF/SS (strike-slip) faulting regime due to overpressure within the Baong formation. On the other hand, the Belumai and Bampo formations show an anisotropic stress state with a normal pressure interval in the NF (normal fault)/SS faulting regime. These conditions lead to a lower minimum principal stress in the Belumai and Bampo formations which suggests that these formations cannot act as a fracture barrier for hydraulic fracturing in the Baong formation. In addition, considering the RF stress state in the Baong formation and the bedding planes that dip at about 30°, horizontal hydraulic fractures can form propagating in all azimuth directions without any obvious fracture barrier preventing them from penetrating into adjacent formations. Meanwhile, hydraulic fracturing in the Belumai formation will create vertical fractures due to the SS/NF faulting regime that will propagate until it reaches the Baong Formation acting as a fracture barrier. Our study suggests that overpressured formations in this region whose prevailing faulting regime is RF are not favorable for hydraulic fracturing operations.
Computational Modeling of Creep Behavior in Shales Induced by Fluid-Rock Interaction
Authors: Prakash R. , Abedi S. 
Published: September 2022

ABSTRACT:
The chemo-mechanical loading of rocks causes the dissolution and precipitation of multiple phases in the rock. This dissolution and precipitation of load-bearing mineral phases lead to the stress redistribution in neighboring phases, which in turn results in deformational changes of the sample composite. The aim of this study is to investigate the link between microstructural evolution and creep behavior of shale rocks subjected to chemo-mechanical loading through modeling time-dependent deformation induced by the dissolution-precipitation process. The model couples the microstructural evolution of the shale rocks with the stress/strain fields inside the material as a function of time. The modeling effort is supplemented with an experimental study where shale rocks were exposed to CO2-rich brine under high temperature and pressure conditions. 3D snapshots of the sample microstructure were generated using segmented micro-CT images of the shale sample. The time-evolving microstructures were then integrated with the Finite element-based mechanical model to simulate the creep induced by dissolution and precipitation processes independent of the intrinsic viscoelasticity/viscoplasticity of the mineral phases. After computation of the time-dependent viscoelastic properties of the shale composite, the combined microstructure model and finite element model were utilized to predict the time-dependent stress and strain fields in different zones of reacted shale.

1. INTRODUCTION
Determination of viscous behavior of shale rocks is key in wide range of applications such as stability of reservoirs, stability of geo-structures subjected to environmental forcing, underground storage of hazardous materials and hydraulic fracturing. Short-term creep strains in hydraulic fracturing can change stress fields and in turn can impact the hydraulic fracturing procedures(H. Sone & Zoback, 2010; Hiroki Sone & Zoback, 2013). While long-term creep strains can hamper the reservoir performance due to the reduction in permeability of the reservoir by closing of fractures and fissures(Du, Hu, Meegoda, & Zhang, 2018; Rybacki, Meier, & Dresen, 2016; Sharma, Prakash, & Abedi, 2019; Hiroki Sone & Zoback, 2014). Owing to these significance of creep strain, it is important to understand the viscoelastic/viscoplastic behavior of shales.
A New Generalized Solution for the Required Strength of the Three Types of Cemented Mine Backfill
Authors: Belem T. , Gélinas L. Ph. , Oke J. 
Published: September 2022

ABSTRACT:
Cemented mine backfills (Cmb) are widely used in underground mining operations. Indeed, for primary and secondary stoping methods, Cmb provides secondary ground support. During secondary stoping, at least one face of the backfill may be exposed, and a failure can occur if the backfill is not strong enough. To ensure the stability of Cmb mass placed in an underground opening with one or more exposed faces during blasting, a given backfill minimum strength is required. The standard practice for assessing the minimum strength of the Cmb is to conduct uniaxial compressive strength (UCS) tests. The minimum required UCS depends on the number of exposed face(s). In the mining industry, a simplified design method is used based on the confined block model. However, most available models do not allow all scenarios to be taken into consideration (e.g., several exposed faces, rockfill, very large stopes, etc.). This paper provides a new generalized 3D solution of the UCS design required for the three main types of mine backfill (i.e., hydraulic fill, paste fill and rockfill) that a designer can use in the design process.

1. INTRODUCTION
Mine backfills are widely used in underground mines in order to dispose waste rocks and tailings from mining operations and to provide temporarily and secondary support during the ore extraction. There are three types of mine backfill that are used in underground backfilling: cemented hydraulic backfill - CHF (or hydraulic fill – HF or slurry fill - SF), cemented paste backfill – CPB (or paste fill - PF), and cemented rockfill (CRF). Nowadays and with technological development, the mines are deeper and deeper (e.g., &gt;2.5 km) for a total extraction such as open stoping, and the stresses induced are very high. But, to ensure the stability of the backfill mass with an exposed face during open stoping, minimum strength is required. There is no standard method of the design of required backfill strength for underground mining since it is a relatively recent technology. The practical observations and the experience of the designer are used in most cases. However, there are rules and principles that should be followed for every design case. First, the method and the environment of the extraction should be identified in order to determine the function of the backfill. The mechanical design of the CPB requires an assessment of the minimum uniaxial compressive strength (UCS) of the backfill, depending on its function (e.g., Belem & Benzaazoua, 2008). For primary and secondary stoping methods, backfill provides secondary support while extracting the neighboring ore (e.g., Cai, 1983; Annor, 1999). During secondary stoping, at least one face of the backfill mass may be exposed, and a risk of failure or instability due to gravity loading can occur if the backfill is not strong enough.
Methodology for Determination of Anisotropic Elastic Constants and Principal Orthotropic Directions from Laboratory Testing
Authors: Loken M. C. , Mellegard K. D. , Johnson J. C. 
Published: September 2022

ABSTRACT:
The Sanford Underground Research Facility (SURF, formerly known as DUSEL) is a dedicated underground scientific research facility located in Lead, South Dakota, at the former site of the Homestake gold mine. The SURF mission includes the construction of large underground cavern openings at depths of about 1500 meters to house large-scale physics experiments. A primary rock mechanics concern is the stability of these proposed large-diameter caverns (up to 165 meters) in a host rock which has been characterized to be orthotropic in the following conditions: (1) geometry, (2) in situ stress, (3) elastic properties, and (4) strength. Of the four dimensions of orthotropy, the third dimension (3) elasticity will be examined in this paper. The objective of this paper is to present the theoretical development and implementation of the equations that define two-and-three-dimensional orthotropic elasticity. The equations are developed based on simple laboratory testing configurations. The development of the three-dimensional equations of orthotropy is given in this paper. The method is validated with a numerical example and applied to a data set of test results performed on SURF rock samples to determine the orthotropic elastic constants and the principal orthotropy directions.

1. THREE-DIMENSIONAL MATHEMATICAL BACKGROUND
Interest in anisotropic rock mass properties is demonstrated in the current literature [1]. In this initial study, laboratory measurements were made on samples taken from Homestake mine at known and preferred orientations each orthogonal to each other. Strains were measured on each face under a known and controlled state of three-dimensional stress. There were a total of 9 measurements on each cylindrical specimen (each modeled as a cubical specimen). This included 3 measurements on each face (2 normal strains and 1 shear strain) that were mutually perpendicular to each other. However, since each of the three normal strains were measured twice on complementary faces, there are only a total of six independent measurements on each sample. Since there are exactly six unknowns (3 elastic moduli and 3 angles of orientation), a unique solution for each sample can be found using the Solver tool in Microsoft Excel.
The Impact of In-Situ Shear Stress on Microseismic Temporal-Magnitude Patterns
Authors: Tan Yunhui , Fang Zijun , Liu Xiaolong (Darcy) , Fradelizio Gian , Evans John 
Published: September 2022

ABSTRACT:
This paper examines microseismic events recorded during hydraulic fracturing which outline faults in the carbonate layers above the target formation. The faults can be grouped into two systems: North-South system (system 1) and North-Northeast-South-Southwest system (system 2) exhibiting different temporal-magnitude patterns. System 1 showed typical patterns similar to a natural earthquake sequence where the main shock is followed by smaller aftershocks. Whereas system 2 showed increasing larger magnitudes with time along with smaller magnitudes varying with the pumping stages. Regional stress orientation suggests that fault system 1 has higher shear to normal stress ratio, which might be the main reason why those faults are capable of hosting large events without much drive from fluid injection. Geomechanical modeling was performed combining hydraulic fracture modeling with dual-porosity-dual-permeability reservoir simulation. Simulation results show that the events on fault system 2 are more likely to be fluid driven (induced), while events on fault system 1 are more likely to be natural events triggered by fluid injection (triggered).

1. INTRODUCTION
Microseismic data has been used as a qualitative measure for assessing hydraulic fracture geometry during the stimulation process in unconventional plays (Maxwell et al. 2010; Grechka and Heigl 2017). It is an effective tool in outlining the stimulated reservoir volume (SRV) to estimate fracture height, length, complexity, and further, this information can be used to optimize well spacing and landing decisions (Tan et al. 2014a; Tan 2015; Warpinski 2009). Microseismic can also shed light to stress regime and pressure depletion level (Dohmen et al. 2014; Tan et al. 2019; Wang et al. 2019). Common source mechanisms observed for microseismic events include bedding-plane-slip/dip-slip (BSDS) and strike-slip. The mechanisms of BSDS events are still under debate: the disagreement centers around which plane actually slipped (Tan et al. 2014 b; Tan and Engelder 2016; Tan et al. 2021; Tan et al. 2022). The strike-slip events are relatively better understood, which are associated with either natural fracture swarms or faults being reactivated during the hydraulic fracturing process (Yang and Zoback 2014).
Efficient and Accurate Thermoporoelastic Fracture Simulation Based on Adaptive Multimeshing
Authors: Poli Renato E. B. , Roseno K. T. C. , Gioria R. S. , Carrion R. 
Published: September 2022

ABSTRACT:
An adaptative multimeshing algorithm is introduced to simulate hydraulic fracture propagation considering temperature evolution in a petroleum reservoir. The methodology enables an implicit solution by which fracture damage is solved semi-explicitly and sequentially, in a pseudo time evolutionary procedure. In the poroelastic medium, the interaction between rock deformation and fluid flow is strongly coupled and solved implicitly in a non-linear Newton solver while the heat flow problem is weakly coupled. This strategy is justified by the quite different time scales of each phenomenon. The results presented herein address performance and accuracy issues, stress parameter setup in fracture propagation and thermal front evolution models. It was found that working with multiple meshes in numerical simulation runs is advantageous because it enables dealing with more complex scenarios while balancing accuracy and computational cost.

1 INTRODUCTION
Hydraulic fracturing is used in the oil and gas industry to improve hydrocarbon production by augmenting well productivity (Baykin, 2020; Wanniarachchi et al., 2018). Numerical models are aids to optimize those stimulation jobs. For a reliable representation of the process, the model must consider the multiphysics process as a whole, dealing with mechanical equilibrium and fluid leakoff at the fracture-reservoir interfaces, fluid flow inside the fracture domain, fluid flow at the reservoir continuum, elastic response of the formation and plastic propagation of the fracture (Baykin, 2020).
Over the decades, mathematical modeling for hydraulic fracture propagation became an integral part of design and analysis of treatments both for stimulation and reservoir characterization (Lecampion et al., 2018). Generally speaking, however, methods are focused on short term stimulation jobs, ignoring thermal or long term mechanical response of the reservoir. This work aims mainly to provide a methodology for consistent and efficient numerical simulation of such complex processes, bringing up comprehensive mesh technologies for bounding computational effort.
نفي الإكراه بين النسخ والتأصيل
Authors: Meras Meras 
Published: September 2022

اهتم البحث بالتحقيق في قوله تعالی: «لااکراه فی الدین قد تبین الرشد من الغي»البقرة:،256، الذي يطلق عليه بعض المفسرين آية نفي الاكراه، ودراسة أهم ما جاء حولها من تفاسیر المذاهب والفرق الاسلامية، محاولاً إثبات حریة العقيدة والفكر من خلال هذه الایة الکریمة ، والرد علی من ادعی عدم امکان ذلک محتجاً بالنسخ ،أو المحدودية الزمانية لصدر الاسلام وضعف المسلمین بداية الدعوة ،أو بحجة إختصاصها بأهل الکتاب اذا دفعوا الجزیة للحاكم الشرعي،أو اختصاصها بمجموعة من الأنصار سالوا النبی(ص) عن مصیر ابنائهم المتهودين ، وما شابه ذلک ،ثم تناول البحث اسباب نزول هذه الایة ، وناقش رای السید الخوئی حولها ، وما فی الایة من الانشاء و التعلیل ومعانی المفردات واحتمالاتها ، والفرق بین الاکراه والاجبار ، وهل ان الاکراه فی الایة مقابل الرضا ام مقابل الاختیار ؟ وتوصل البحث أخيراً الى ان هذه الآية وامثالها تؤصّل لحرية الاعتقادالديني في الاسلام خلافاً للاتهامات الباطلة.
النداء بالصوت في القرآن الكريم / دراسة في الاسلوب
Authors: Dr. Najah Hussein Kattan  
Published: September 2022

للنداء اكثر من معنى اهمها هو الدعاء برفع الصوت ويكون المنادى هو الشخص أو الجهة المطلوب إقباله بحرف مخصوص .
وقد بين علماء اللغة أن للنداء سبعة أحرف ، منها ما هو مختص بنداء البعيد حساً أو حكماً ونعني بحكما المنادى المنزل منزلة البعيد ، لرقود أو غفلة أو علو محل أو انخفاضه ، ومن ذلك ما استخدم في نداء العبد خالقه ، ونداء الخالق عبدَه .
وقد استعمل الله سبحانه وتعالى أسلوب المناداة في أمر الاستماع إلى بعض من آياته العظيمة حيث نزلت آيات القرآن الكريم لغاية عظيمة الشأن في أمر الاستماع إلى آيات الرحمن ، لما فيها من قوة العبارة وبلاغة المعنى وحسن الأسلوب ، وجاء هذا الاستماع متنوعاً في صياغته ،
إن أصوات حروف القرآن الكريم هي نفسها حروف العربية لكن أسلوبه أفاد من الصوت ما فارق به أساليب الكلام العربي ، وهذا يتضح في القيمة التعبيرية للصوت وقد يتكرر الصوت وفي تكراره تصوير للموقف وتجسيم وإيحاء مما يدل على أن نغمة الجرس تسهم في إبراز المعنى المراد، ولعل أهمية صوت القرآن يتمثل في الإفادة منه في التأثير في الناس حيث نزل القرآن مسموعاً لا مكتوباً .
وإذا ما عدنا إلى الصوت وتأثيراته ، نجد ان القران الكريم حافل باسلوب المناداة لاجل الاسماع ومن ذلك امره لابراهيم علية السلام بمناداة الناس داعيا لهم لحج بيت الله العتيق وهذا واضح من قوله تعالى ((واذن بالناس للحج )) .
الاحتراز في العربية كتاب همع الهوامع في شرح جمع الجوامع للسيوطي (911هـ) أنموذجا
Authors: Dr. Alaa Saleh Obaid Al Asadi  
Published: September 2022

تحاول هذه الدراسة التطرق إلى موضوع مهم من موضوعات النحو العربي نجد أنه أخذ حيزًا لا بأس به عند النحويين والمفسرين والبلاغيين وهو " الاحتراز في العربية كتاب همع الهوامع في شرح جمع الجوامع للسيوطي (911هـ) أنموذجا " كان النحويون والمفسرون والبلاغيون يستعرضون هذه الظاهرة النحوية لغرض دلالي إذ لا يأتي الاحتراز إلّا لأجل المعنى ولأنّ موضوع الاحتراز كبير جدًا في كتب النحو وله مرادفات اصطلاحية لذا اكتفت الدراسة بدراسته في كتاب همع الهوامع فقط