bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular Dynamics Simulation Insights into CO2 Wettability of Low-Maturity Shales Organic Matters Under Various Reservoir Conditions
Authors: Cheng Kai , Peng Bo , Arif Muhammad , Zhang Yupeng , Wang Shushuai , Shang Leiwang 
Published: May 2024

Abstract
Geological CO2 sequestration (GCS) stands as a principal global strategy to mitigate greenhouse gas emissions and address climate change. Injecting CO2 into shale not only reduces carbon emissions but also enhances oil recovery. Rock wettability significantly determines CO2 trapping efficiency. Shale consists both hydrophilic inorganic and organic matter like kerogen. Although traditionally viewed as hydrophobic, kerogen has been underscored in recent studies for its potential weak water-wettability. Consequently, understanding this behavior is crucial for GCS.
Utilizing molecular dynamics simulations, we selected the quintessential kerogen type-Ⅰ A from low-maturity shale organic matter. Initially, we constructed a shale organic matter plate model via high-temperature annealing and subsequently amalgamated it with water and CO2, establishing a foundational model for wettability studies. Subsequently, we determined the contact angle of the kerogen plate with air. Then, based on NIST's relationships among density, temperature, and pressure from NIST handbooks, we adjusted the quantity of CO2 to mirror actual reservoir conditions. Ultimately, we assessed the contact angle between CO2 and low-maturity shale within a temperature range of 298.15k-358.15k and pressures of 5-65MPa.
The study reveals that low maturity kerogen in shale organic matter is predominantly weakly water-wet. Under reservoir conditions, variations in temperature and pressure significantly influence the wettability of shale organic matter. Specifically, at a constant pressure, an increase in temperature results in a decreased contact angle, whereas at a consistent temperature, an elevated pressure leads to an increased contact angle. Consequently, the wettability of shale organic matter transitions from being weakly water-wet to predominantly CO2-wet. Enhanced accumulation of CO2 molecules at the H2O-kerogen interface and the emergence of apparent CO2 films indicate that kerogen exhibits substantial CO2 adsorption. Low maturity shale organic matter is thus conducive to the capillary trapping of CO2, facilitating its geological sequestration.
In this study, a low-maturity shale organic matter model was established using molecular dynamics simulation to investigate the effect of CO2 on the wettability of shale organic matter. By examining the water contact angle in various reservoir conditions saturated with CO2, we addressed challenges in assessing shale wettability in such environments. Furthermore, we discerned that low-maturity kerogen exhibits enhanced CO2 capture capability, underscoring its significance in geological carbon sequestration.
Best Practices for High-Temperature Gas Well Abandonment Plugs
Authors: Khan Anum Yousuf , Salazar Jose , Bogaerts Martijn , Rashdi Issa , Wardi Yasser Al , Habsi Younis , Bahri Salim Al , Noumani Abdullah Al , Parasher Mukesh , ElShaarawey Ahmed , Hinai Mohammed Al , Mughairy Mohammed AL 
Published: May 2024

Abstract
Wellbore abandonment in high-pressure, high-temperature (HPHT) wells is an exceptionally challenging operation in the drilling phase because it must satisfy the abandonment criteria but also must ensure that the placement and pullout of the cement plug occurs without obstructions. In this paper we aim to detail the best practices acquired for placing cement plugs under such well conditions.
Our methods cover both slurry design and placement practices. Instead of having multiple diameter shifts, the placement pipe was selected to minimize contamination. Best practices for plug pull out of hole (POOH) included calibrating the openhole diameter to ensure the displacement was accurate. For the fluid designs, not only were density and fraction hierarchies followed, but the important step was ensuring fluid compatibility in downhole conditions. Being a gas well and with exposed flow zones in the open hole, the plug had to be designed as gas tight. HPHT gas-tight cement must present stability at HPHT downhole conditions to prevent any potential settling or free fluid that can compromise its performance. Fluid loss and thickening time properties are tailored accordingly, with tight fluid loss control below 50 mL/30 min API and enough safety margin for a challenging environment. The cement spacer also is a crucial fluid in the cement plug placement to prevent contamination of the cement slurry and provide the proper density and rheology hierarchy for mud displacement but is easy to be displaced by the cement slurry.
Many of the design inputs were verified with execution. First, the POOH fluid levels indicated the caliper assumptions were correct. This was further verified with the returns data post-job circulation. The cement tag after wait on cement (WOC) assured us of the contamination simulation outputs, as the cement was tagged on the desired depth and the well was stable.
We will cover the details of additives and simulations that aided in ensuring the HPHT cement plug design met objectives. By applying the entailed best practices, this execution was the first successful abandonment for a deep gas well for the Amin Formation in Block 60.
Case Study-Abnormal Delay in Project Completion
Authors: Kumar Sanjeev 
Published: May 2024

Abstract
A project is a temporary endeavor required to be completed on schedule to have a win-win situation for all stakeholders. Delay in project completion always leads to financial stress for most stakeholders, and the project is not considered successful. Every project is unique and has a set of distinctive challenges to deal with during the execution of the project. The case study is about an unorthodox delay in one of the major projects executed in Kuwait by a multinational contractor. This case study reviews the entire project execution- detailed design to commissioning and tries to jot down possible reasons for the delay. It also concentrates on probable remedial action/suggestions to avoid these reasons to have a successful project.
A Data-Driven Approach for Hydraulic Fracturing Simulation in Shale Based on Time-Series Images of Fracture Propagation
Authors: Zhao Mingze , Yuan Bin , Zhang Wei , Han Mingliang 
Published: May 2024

Summary
Optimizing the hydraulic fracturing design requires efficient and accurate simulation of fracture propagation. However, traditional numerical methods are computationally expensive due to the solution of coupled differential equations, and the simulation accuracy may be reduced by the uncertainty of the input parameters (e.g., rock mechanical and fluid properties). To address these issues, this paper proposes a deep-learning-based approach to improve both the efficiency and accuracy of fracturing simulation in shale.
This study develops a novel method integrating Feedforward neural network (FNN) and ConvLSTM to predict fracture propagation in shale. We concatenate the well position images, natural fracture images, and the time-series images of fracture propagation, and use FNN to extract the features of reservoir properties and pumping schedules at each timestep as the input of model. Then, the ConvLSTM network is utilized to extract and fuse features from natural fractures, wellbore locations, and the features extracted by FNN. Data preprocessing techniques are employed improve data quality through cleaning and normalization.
Fracture propagation images, wellbore images, natural fracture images, and pumping schedules for hydraulic fracturing were generated using fine-grid hydraulic fracturing simulation. Based on the various settings of different geologic and operational parameters, a dataset with over 1 million samples was established by collecting the fracture propagation image at each frame. The proposed model predicts the fracture morphology images in the next 5 frames based on the fracture propagation history image of the previous 1 frame. The model was evaluated using Structural Similarity Index (SSIM), Mean Squared Error (MSE) and Frame Mean Absolute Error (FMAE). To expedite model training convergence, the Scheduled Sampling technique was incorporated. After 500 iterations of training, the model demonstrated an MSE less than 15×10-5, a maximum SSIM of 0.90, and an average FMAE below 50. In comparison with traditional fracturing simulation using the finite element method, the proposed data-driven method demonstrated a 60% improvement in simulation efficiency.
The main value of this work lies in the development of a new data-driven and mesh-free method for predicting fracture morphology, which eliminates the numerical computation issues so that fast and accurate predictions of fracture propagation can be achieved. Without the heavy computational cost in the traditional fracturing simulation, the developed workflow can be integrated with reservoir simulation and optimization algorithms to perform fast and reliable optimization of fracturing design.
Sh_Pyroil for a Cost-Effective and Rapid Geochemical Pyrolysis Technique for Direct Hydrocarbon Saturation So Evaluation
Authors: Koksalan T. , Hanif R. , Ahsan S. A. 
Published: May 2024

Abstract
In carbonate and clastic reservoirs, determining the saturation levels based on log interpretation can be difficult. The traditional method of deriving saturation values using Archie's equation involves measuring "a," "m," and "n" factors on samples that are highly variable within a core. However, this approach assumes constant values for these factors throughout the entire reservoir section or a given rock type, leading to inaccurate hydrocarbon saturation measurements and impacting volume estimations. We propose an alternative solution that is real-time, cost-effective, and provides high confidence in identifying sweet spots for selecting perforation zones in a vertical well and plugging high water saturation zones in a horizontal well.
Our solution involves a modified pyrolysis technique, which we refer to as "Sh_Pyroil." This technique enables the rapid (within 3 minutes) and low-cost measurement of direct hydrocarbon saturation. Sh_Pyroil is quantified in milligrams of hydrocarbons per gram of rock weight (mg HC/g rock) and can be easily converted into a percentage value for hydrocarbon saturation. To test the efficacy of this technique, we used modified pyrolysis on 90 core plugs extracted from dense and oil-bearing zones at one-foot intervals.
The objective of our study was to compare the hydrocarbon saturation values obtained through thermally extracted core analysis using Sh_Pyroil with the saturation values derived from log interpretation (Archie's equation). This comparison allowed us to assess the applicability of Sh_Pyroil as a rapid, cost-effective, and high-confidence tool for directly measuring hydrocarbon saturation. Furthermore, the use of Sh_Pyroil can assist in making time-sensitive drilling and completion decisions, such as selecting optimal perforation zones and identifying high water saturation zones for plugging. Additionally, it can help in keeping horizontal wells within sweet spots and in estimating in-place hydrocarbon volumes in both conventional and unconventional reservoirs.
Study on Wellbore Stability of Shale Formation Based on Three-Dimensional Weak Plane Strength Criterion
Authors: Gao Jiajia , Bian Gengchen , Lin Hai , Zhang Binqi , Wang Zhe , Chen Fuzhi , Yang Weidong 
Published: May 2024

Abstract
Deep formation rich in the weak plane (bedding, micro-fractures) has strong strength anisotropy and is the internal control factor of frequent wellbore instability of the long horizontal section of shale gas wells, which seriously restricts the realization of improving drilling quality and efficiency. The conventional single plane or multi planes of weakness criterion only considers the pseudo-triaxial loading state (σ2 = σ3) or the loading direction of the intermediate principal stress σ2 coincides with the failure plane of weakness. Based on the theory of elastic mechanics and the Mogi-Coulomb shear failure criterion, this paper establishes the rock strength criterion considering the influence of the weak plane and three-dimensional stress loading. One analyzes the influence of three-dimensional stress on the strength of rock possessing parallel plane of weakness, the variation of equivalent density of wellbore collapse pressure in different time domains, and the influence of wellbore trajectory on wellbore stability considering different occurrences of the weak plane. The results show the obvious influence of intermediate principal stress on the failure of the rock matrix and the weak plane. The strength of the rock matrix first increases and then decreases with the increasing σ2. At a given small dip azimuth angle, the rock strength is controlled by the rock matrix and the weak plane for smaller σ2, while the rock strength is completely controlled by the rock matrix for larger σ2. The strength of the weak plane does not depend on σ2 where the dip azimuth angle coincides with the failure plane of weakness. At a given σ2, the range of failure angle of the weak plane gradually increases with the increasing dip azimuth angle. At a given minimum principal stress σ3, the apparent strength of the rock matrix increases with the increasing σ2. The larger angle between the borehole axis and the normal direction of the weak plane weakens the wellbore stability related to borehole collapse. Besides, the magnitude of the time-dependent equivalent density of collapse pressure descends in short-time, modified instantaneous, long-time, instantaneous, and elastic ones. Introduction of the influence of three-dimensional stress on the strength of rock possessing parallel plane of weakness and time-dependent stress and pore pressure solutions around a borehole is conducive to improving the prediction accuracy of equivalent density of collapse pressure and can help solve the problem of wellbore collapse in complex shale formations.
Red Mud-Based Geopolymer Cement for Sustainable Oil Well Construction: Opportunities and Challenges
Authors: Mahmoud Ahmed Abdulhamid , Abdelaal Ahmed , Elkatatny Salaheldin , Shehri Dhafer Al 
Published: May 2024

Abstract
Red mud is a waste byproduct of aluminum production that can pose significant environmental challenges. However, recent studies have shown that red mud can be used as a raw material for geopolymer cement for construction purposes, which could also potentially have applications in the oil and gas industry. This paper aims to review the potential of red mud-based geopolymer cement for use in oil and gas wells, including its chances, possibilities, and complications. Geopolymer cement has several advantages over traditional Portland cement, including lower carbon emissions, improved durability, and higher resistance to chemical attack. However, the production of geopolymer cement typically requires the use of high-quality raw materials, which can be expensive and may not be readily available in all locations. Red mud is a waste material that is generated during the extraction of alumina from bauxite ore. Red mud contains significant amounts of alumina, silica, and iron oxide, which are the primary components for geopolymer cement production. Consequently, red mud possesses the potential to be a low-cost and readily available source of raw materials for geopolymer production. Many research studies have explored the application of geopolymer cement derived from red mud for diverse purposes, including construction materials, wastewater treatment, and soil stabilization. However, red mud-based geopolymers for oil and gas wells are relatively unexplored. Oil and gas wells require cement with high compressive strength, low permeability, and resistance to high temperatures and aggressive chemicals. Therefore, the potential of red mud-based geopolymer cement to be used in oil and gas wells is an interesting topic for further investigation. This paper reviews some existing literature on the use of red mud-based geopolymer cement and its potential applications for well cementing. The review will focus on the key properties of red mud-based geopolymer cement. The review will also discuss the challenges and complications accompanying the use of red mud-based geopolymer cement in oil wells, such as the potential for corrosion and the effects of different types of oilfield fluids on the cement properties. In conclusion, red mud-based geopolymer cement has the potential to be a cost-effective and environmentally friendly alternative to traditional Portland cement in oil and gas wells. However, further research is needed to fully evaluate the suitability of red mud to be incorporated in well cementing, and to address the challenges and complications associated with this application.
Case analysis of 24 cases of Oxyntic gland neoplasm of the stomach
Authors: Xie Xinyuan , Zhang Yahan , Sun Jianhui , Liu Yangcheng , Yang Gang 
Published: May 2024

Abstract

Background:Stomach oxyntic gland neoplasms such as oxyntic gland adenoma (OGA) and gastric adenocarcinoma of fundic gland type (GA-FG) have been included in the World Health Organization's List of Digestive System-related Malignancies in 2019. Due to the rare occurrence of the disease, some patients have been diagnosed incorrectly in certain clinical settings. This study aimed to investigate the clinicopathological aspects of Stomach oxyntic gland neoplasms by retrospectively examining clinical features, endoscopic evidence, and pathological findings to aid future clinical diagnosis.Materials and methods:A total of 45 patients with verified diagnoses of OGA and GA-FG, as well as other benign lesions were collected from a similar time duration. Patients were divided into three groups and their clinical course was studied both prospectively and retrospectively. Clinical information, including endoscopic characteristics, pathological appearance, and immunohistochemistry for MUC5AC, MUC6, CDX2, KI-67, and P53, SYN, and CgA, were analyzed in detail.Materials and methods:A total of 45 patients with verified diagnoses of OGA and GA-FG, as well as other benign lesions from the same time period, were collected from the researchers and separated into three groups, with the clinical course of all patients being studied prospectively and retrospectively. This involved comparing and analyzing available clinical information, endoscopic characteristics, pathological appearance, and immunohistochemistry for MUC5AC, MUC6, CDX2, KI-67, and P53, SYN, and CgA.Results:The 45 patients' clinical and pathologic data were divided into three groups, 18 OGA patients, 6 GA-FG patients, and 21 patients with other benign lesions. All lesions were multi-evidence confirmed. Narrow-band imaging endoscopy characterized GA-FG with the absence of clear margins. Fluorescent stain of MUC6 positively, MUC2 negatively expressed specimens further confirmed OGA and GA-FG cases. In our comparison of the three groups, gender,Hpinfection, and endoscopic subepithelial changes were statistically significant among the three groups. We also observed the expression differences between groups in some hall markers. While there was no overexpression of P53, and the Ki-67 labeling index varied between 4.6% and 8% in GA-FG and OGA cases. In addition, lymphatic and vascular infiltration confirmed metastasis and recurrence were not detected in any of the cases.Conclusion:Overall, this study reports 24 cases of Stomach oxyntic gland neoplasms. While most clinical variables align with previous reports, a few of them, such as gender bias, were observed among the three groups in this study. Other key features, such as endoscopy, the hall marker stating, and treatment methods, were characterized throughout this study.
The Role of CDCA3 in Disulfidptosis: Implications for Breast Cancer Cell Viability and Treatment
Authors: chen minbin , wang anran , Zhu Xiaoren , zhu xaioren , Liu Yuanyuan , Wu YuJiao , Xue MengEn 
Published: May 2024

Abstract

"Disulfidptosis" is a novel concept, primarily characterized by the depletion of intracellular NADPH during glucose deprivation, leading to the accumulation of disulfides. This accumulation triggers disulfide stress, breakdown of the actin cytoskeleton, and ultimately, cell death. Breast cancer, being a highly prevalent cancer type, requires a substantial amount of glucose for its rapid growth and division. Glucose deprivation induces rapid cell death, possibly associated with the process of disulfidptosis. In this study, we developed a novel signature based on 10 machine learning algorithms integration. Compared to the traditional TNM staging, this new predictive model demonstrates superior predictive capabilities. Among the 13 genes included in the signature, CDCA3, a cell cycle-regulating protein, is expressed at higher levels in breast cancer. Our experiments indicate that breast cancer cells (SKBR-3 and MCF-7 lines) with downregulated expression of CDCA3 through shRNA exhibit reduced proliferation, migration, and invasion capabilities compared to the WT cells. Conversely, breast cancer cells with forced overexpression of CDCA3 show enhanced growth and mobility. Moreover, observations of primary and immortalized breast cancer cells in a glucose-deprived environment reveal that overexpressing CDCA3 can slow down the process of cell cytoskeleton contraction under starvation conditions, while knockdown CDCA3 accelerates this change. In conclusion, CDCA3, associated with the process of disulfidptosis, may represent a new target for breast cancer treatment.
Revealing the Microscopic Mechanism of Elementary Vortex Pinning in Superconductors
Authors: Zhang Tong , Chen Chen , Liu Yue , Chen Yun , Hu Yining , Zhang Tianzhen , Li Dong , Wang Xu , Wang Chenxi , Lu Zouyouwei , Zhang Yuhang , Zhang Qingle , Dong Xiaoli , Wang Rui , Feng Donglai 
Published: May 2024

Abstract

Vortex pinning is a crucial factor that determines the critical current of practical superconductors and enables their diverse applications. However, the underlying mechanism of vortex pinning has long been elusive without a clear microscopic description1,2. Here using high-resolution scanning tunneling microscopy, we studied single vortex pinning induced by point defect in layered FeSe-based superconductors. We found the defect-vortex interaction drives low-energy vortex bound states away from EF, resulting a “mini” gap which effectively lowered the system energy and caused the pinning. By measuring the local density-of-states, we directly obtained the elementary pinning energy and estimated the pinning force through the spatial gradient of pinning energy. The results align with the bulk critical current measurement. We further show that a general microscopic quantum model with considering defect-vortex interaction can naturally capture our observation. It indicates the local pairing near pinned vortex core is actually enhanced, which is beyond the traditional understanding that non- superconducting regions pin vortices1-3. Our study thus reveals a general microscopic mechanism of vortex pinning in superconductors, and provides guidance for enhancing the critical current of real superconductors.