bluuebunny/crossref_metadata_2025_split huggingface dataset:
Advanced Rock Mechanical Characterization of Giant Cretaceous Carbonate Sequence for Reservoir Development
Authors: Noufal A. , El Wazir Z. , Al Madani N. , Shinde A. L. , Benmamar S. , Perumalla S. , Aldin M. , Govindrajan S. , Gokaraju D. 
Published: November 2024

Abstract
Advanced rock mechanical characterization of a giant Cretaceous carbonate field in Abu Dhabi is the focus of this paper, that not only focused on routine triaxial tests for shear strength estimates but also to understand pore collapse, tensile strength, thermal and creep behavior of these rocks.
The approach has started with auditing and selection of core intervals from various offset wells. These core intervals are selected to represent lateral and vertical coverage of various sub-units within various reservoir and caprock intervals. Scratch tests and whole core CT scans are conducted for selection of appropriate intervals for extracting core plugs. Specialized techniques are deployed for plugging the core intervals. Pre and post-test photographs and CT scans of all the plugs are taken to identify the role of heterogeneity.
The testing program encompasses various triaxial tests such as single stage (SST), multi-stage (MST), and unconfined compressive strength (UCS) tests. They are crucial for understanding rock shear failure, strength parameters like UCS, cohesion, friction angle, and stiffness properties including Young's modulus and Poisson's ratio. Acoustic velocity is also recorded during these tests. Additionally, tests like uniaxial pore volume compressibility (UPVC) and Biot are performed to ascertain the compressibility and poro-elastic coefficients. Hydrostatic compaction tests provide insights into pore collapse onset, while Brazilian tests measure tensile strength, and fracture toughness tests assess resistance to crack growth. We also conduct thermal expansion and creep tests to determine the rocks’ thermal behaviour and time-dependent deformation characteristics.
Based on the results of rock mechanics testing program, mechanical rock properties correlations have been developed for various reservoir units and caprock. These correlations demonstrate a relationship between geomechanical and petrophysical properties. The developed bespoke correlations have been successfully used across different wells, demonstrating accurate core-log calibrations of mechanical rock properties. This high-level characterization of carbonate reservoirs and caprocks aid in comprehending rock behavior under various field development conditions: such as reservoir depletion, fluid injection, potential CO2 sequestration, and modeling of thermal and creep phenomena.
Performance Analysis of Digital Underreamers in Motorized Bottom Hole Assembly
Authors: Ashish Sanan. , Singh Bagga. Pawandeep , Mansi Maheshwari. 
Published: November 2024

Abstract
Expandable reamers were developed to enhance operational efficiencies and minimize risks during the drilling process in challenging formations found in deep-water and offshore wells. These tools are particularly valuable in addressing the significant challenge of ensuring wellbore stability in such environments. The initial concentric expandable reamers were activated by a ball mechanism, and once expanded, they remained open until circulation was halted. In the subsequent version, modifications were made to enable deactivation, allowing circulation even after reaming for improved hole cleaning. The concentric expandable reamer offered several advantages over its mechanical-arm predecessors. These included the ability to achieve a larger borehole size to accommodate larger bottomhole assembly (BHA) components, flexibility in choosing pilot bits, higher flow rates, and the capability to ream a previously drilled hole or back ream a hole after drilling.
The digitally controlled, expandable under reamer, activated as needed, is seamlessly incorporated into BHA and can be remotely monitored and managed from the surface. Real-time feedback from the reamer includes data on tool vibration and stick slip (VSS), along with confirmation of blade activation status and precise blade position (fully retracted, fully extended, or in transit between the two positions). The extended blade position is pre-set to a specific surface position, and upon activation, the reamer opens to this position to initiate reaming operations. This real-time feedback minimizes operational uncertainties during reaming, streamlining the shoulder test process and saving time.
With unlimited activation cycles, the reamer offers the capability for selective reaming. The flexible arrangement of multiple reamers within the BHA allows for both near-bit and main reaming applications. Intense study of Bit and Cutter on reamers is needed to deliver wells flawlessly. Also, the motor on top of reamer provides sufficient RPM to obtain drilling performance.
The paper discusses in detail the concept of Installing the underreamer below the mud motor and showcases how it worked successfully in four recent wells, saving a trip for the operator in each well. The paper will also compare multiple Bottom Hole assemblies where the concept of Motorized Underreamer was used with wide range of well profiles including vertical to highly deviated wells. Every well had its own challenges and Intense pre job planning was done to successfully complete the wells. The target depths of well ranged from 2500m to 5500m. Body text 2 paragraphs.
Development of a Risk-Based, Modelling Framework for Integrity Assessment of Legacy Wells in CO2 Storage Applications
Authors: Ghanbari S. , Sefat M. H. , Davies D. , Murray J, , Bonfanti R. Oropeza , Martin I. 
Published: November 2024

Abstract
Demonstrating the integrity of Plugged and Abandoned (P&A'd) legacy wells during CO2 storage projects is a crucial requirement for regulators, stakeholders, and operators. The corrosive nature of CO2 may affect the integrity of such wells, jeopardising the long-term containment of the CO2. This study illustrates the new capabilities, tailored for CO2 storage applications, of a modelling framework (Johnson et al, 2021a&b) that provides a quantitative, risk-based assessment of the long-term integrity of legacy P&A'd wells. The following three new modelling modules are added to this integrated framework to account for the key concerns due to the presence of CO2 in the system:
The cement-CO2 geochemistry "add-on" module evaluates the phenomenon of cement's self-sealing/self-degradation behaviour. Carbonated water reacts with cement minerals; some of which are initially dissolved followed by a possible precipitation process that is controlled by the fluid's flow rate/residence time in the cement defects such so microannuli. The self-sealing mechanism can reduce the microannuli's width, potentially stopping CO2 leakage, while self-degradation has the opposite effect. The geomechanical "add-on" module quantifies changes in the size of defects within the well P&A system when the pressure/stress changes during the CO2 storage process. Pressure/Stress variations change the radius of the casing and the size of the adjacent microannuli, altering the leakage rates within the legacy well system. The elastic/plastic stress behaviour of cement can potentially contribute to increasing risks. The CO2/casing corrosion "add-on" module estimates the rate of casing corrosion and subsequent reduction in casing thickness over time based on experimental data. Excessive corrosion can lead to casing breach. These processes increase the size of defective leakage paths and increase the leakage risk from the legacy well.
On completion, the modelling framework will be capable of being an integral part of the risk-assessment process when (a) selecting between possible CCUS projects and (b) supporting operators, regulators and other stakeholders in their decision-making process when analysing CCUS proposals.
A Practical Approach to the Numerical Simulation of Vertical Wells with Negative Skin Factors on Fine-Scaled Grids
Authors: Saadawi Omar , Hirakubo Yasushi 
Published: November 2024

Abstract
In a numerical simulator, the inflow from the reservoir grid into a producer well is governed by well connections. The transmissibility of each well connection is calculated using a connection transmissibility equation. On Cartesian grids, the pressure equivalent radius ro is calculated using Paceman's formula. To ensure the denominator of the transmissibility equation remains positive, it is necessary for the term ln(ro/rw), where rw is the well radius, to be greater than the dimensionless skin factor S.
However, when using fine-scale local grid refinements (LGRs) and reducing the grid block size, the term ln(ro/rw) approaches zero, limiting the effective magnitude of the negative skin value. Increasing the grid size can overcome this issue, but for certain cases smaller grid sizes are necessary to accurately model the flow from the reservoir into the well. This paper aims to present an alternative practical approach to address this problem by applying a permeability multiplier to a "skin zone" across the near-wellbore grid cells, while still accurately equating it to an equivalent dimensionless skin factor.
To demonstrate the proof of concept, a simple 2-dimensional, homogeneous, water-bearing, single-well, numerical model was created. Various cases were simulated with different grid sizes, skin zone multipliers, and skin zone radii. An equivalent analytical model using the infinite-acting radial flow equation was then used to develop a relationship between the analytical skin factor and the numerical skin zone (multiplier and radius) for different grid sizes. A clear correlation was found between the analytical model and the numerical model of the simple 2-dimensional model. Using this correlation, the work was successfully extended to real field tests.
Based on the results of this work, the following conclusions can be made. As the grid size is reduced in the numerical model, the minimum effective skin factor ‘S’ increases. The minimum effective skin factor for a given grid size can be calculated analytically using the well radius and the grid dimensions. An equivalent "skin zone" (i.e., permeability multiplier in a defined area around the wellbore) can be used on any grid size to replicate the analytical model skin factor. A correlation has been developed to identify the necessary skin zone permeability multiplier and skin zone radius to replicate negative dimensionless skin factors for vertical wells on fine-scale grids.
This work demonstrates a practical and reliable alternative for reservoir simulation engineers to numerically simulate vertical wells with high negative skin factors on fine-scale grids. A mathematical correlation is presented to inform the engineer of the required skin zone radius and permeability multiplier necessary to model the equivalent negative dimensionless skin for various fine-scale grid sizes.
ESP Successful Optimization Using Variable Frequency Drive Current Limit with Combined System Technique, Production Enhancement in Colombia Llanos Field
Authors: Martinez Yuly , Figueroa Paula , Castro David , Garzón Miguel , Ariza Iván , González Camilo , Aguinaga Pilar , Devia Nestor , Mazabel Katherine , Jaramillo Javier , Camelo Sebastian 
Published: November 2024

Abstract
One of the main challenges during the operation of an ESP system is to achieve a stable production, this can be guaranteed by an appropriate monitoring of electrical and downhole sensor parameters. However, the conditions of a field located in the Llanos Orientales Basin in Colombia, where there is high presence of free gas in the T2 and comingled K1-T2 formations, cause high instability in the operating parameters of the ESP systems, leading to several shutdowns and causing high levels of deferred production. In the past, the configuration of motor current controls and PID algorithms in the variable speed drives were not enough to achieve smooth operation causing premature ESP failures and incurring in high well intervention costs.
This paper describes a successful study case of the application of the limit control parameter in the variable speed drives for the Llanos field (area Apiay) operated by Ecopetrol and offers a different approach to running the limit controls on the drives. With this methodology, smooth operation was achieved in several challenging wells, increasing the system efficiency, while extending the equipment run life and avoiding costly workovers.
Enabling Methane Emission Detection and Quantification in Robots
Authors: Schillaci Guido , Pencelli Manuel , Fiorucci Marta , Bonacchi Luigi Bono , Gori Valentina , Meloni Enrico , Paladini Lorenzo , Mattioli Erika , Russo Lorenzo , Salusti Lorenzo , Cioncolini Stefano , Politano Andrea , De Magistris Giovanni , Porciani Daniele 
Published: November 2024

Abstract
Methane is a potent greenhouse gas, contributing significantly to global warming and climate change. Methane emissions from natural gas systems have gained increasing attention due to their environmental and economic implications. The detection and quantification of methane leaks and emissions are crucial for minimizing their impact on the environment and ensuring the safety and efficiency of natural gas infrastructure. In recent years, advancements in sensor technology have provided new opportunities for accurate and cost-effective methane leak detection and quantification.
This paper aims to provide an overview of the current state-of-the-art in methane leak detection and quantification using sensors, focusing on the types of sensors, sensing principles, and applications. A particular focus is given to sensors that can be installed on mobile robots and drones. Traditional methods for methane leaks detection and quantification have limitations in terms of spatial and temporal resolution, cost, and accessibility. Robots equipped with gas and methane leak detection sensors have emerged as promising solutions to address these challenges.
This work contributes to the development of more effective strategies for reducing methane emissions and mitigating climate change. In particular, this paper explores the adoption of advanced sensors - such as Tunable Diode Laser Absorption Spectroscopy (TDLAS) sensors and optical gas imaging (OGI) cameras - and their integration into robots. We discuss the advantages of using these platforms for methane detection, including their ability to access hard-to-reach areas, real-time data acquisition, and high spatial and temporal resolution. Furthermore, we present an application in which we integrated methane and gas leak detectors on the payload of a legged robot, and we introduce a testing architecture for assessing the quality of standalone and mobile sensors for methane detection and quantification.
This manuscript is structured as follows. First, we review the state-of-the-art on sensors for methane leaks detection and quantification. We deepen the discussion by reviewing the most relevant robotic solutions integrating gas and methane leak sensors, highlighting their advantages and limitations. Therefore, we present our current work on integrating a methane leak detection sensor on a legged robot. We introduce also our current activities and architecture for testing OGI cameras. We conclude the paper by showing the opportunities that our solutions can bring, and by highlighting challenges and limitations of current sensing technologies to overcome.
Artificial Intelligence Driving Automation to Enhance Drilling Operations—First Deployment Offshore Africa Case Study
Authors: Zarra A. F. , Medea A. , Bianchini L. P. , Borra S. , Gravante E. , Szemat-Vielma W. , Banjo M. , Mouzali N. , Botnan E. 
Published: November 2024

Abstract
Artificial-intelligence (AI) driven systems are becoming the new standard in the drilling domain. This is the first field application performed offshore in Africa with the main objective of enhancing drilling operational efficiency and bottomhole assembly (BHA) integrity by advising the optimal drilling parameters, operational procedures, and drilling dysfunction mitigations.
This smart system, driven by AI, seamlessly integrates the drilling operations planned engineering and procedures with the real-time operational data to monitor and control the operations execution using a data-driven approach. By design, this system enables the coordination and integration of the data and teams through a digitally orchestrated process, while the AI is primarily in control of the operations. The system's current and next steps can be easily visualized and overridden by the driller if and when needed.
For this first application in Africa, close coordination and collaboration between the operator, the technology and service provider, and the rig contractor was a key element from the early stages of the project. A rig survey determined the most appropriate locations for the required equipment on the rig. Once the system was deployed and commissioned, the calibration was performed on the top-hole drilled sections, while the driller received hands-on training with the utilization of the system. The system seamlessly loaded the digital drilling program and recalibrated the operational parameters, which included the rate of penetration (ROP), revolutions per minute, weight on bit (WOB), and flow rates, using the real-time data. At the time of writing, a total of three wells, each with three sections were drilled using this application, resulting in continuous ROP improvement up to 2.5X factor on the last well. The combination of science-based models with real-time data running on the edge device at the rig enabled a step-change in the way AI-driven systems can drive automation, thereby enhancing the drilling operations.
In this paper we will briefly describe the reasoning from the operator the decision to continue with this digital transformation of the operations process, and the technical requirements and process for the first successful deployment in Africa, with an overview of the results achieved. Moreover, we will also describe a novel workflow for a fully autonomous operation that combines several smart applications enabling a seamless digital collaboration between the office and the rig.
Remal Project: Utilizing AI & Data Analytics to Predict Sand Movement on Gas Plant in the UAE
Authors: Alkhoujah K. , Al Ali A. , Al Ghassani M. , Al Mansoori M. , Al Ameri M. , Bhatta Y. , Dieterle A. 
Published: November 2024

Abstract
Shah Gas field (SGF) is located within the Empty Quarter desert premises, where the sand dunes are prominent with varying heights up to 40 m. If the sand blows are severe, the sand would cover the access road and block the access and disrupt plant activities. SGF team regularly patrol to check several facilities including Main Asphalt roads, Gatch Roads, Gas Gathering Pipelines Corridors, Well Pads boundary, Main Plants boundary and the major product pipelines corridor to inspect and report of any sand accumulations that require to be cleared. Accurate detection and forecasting of sand accumulation is crucial for scheduling sand cleanup activity and successful oil transport. As it requires huge manual effort and is not cost-effective to measure the true value of sand accumulation at different geographical areas. This paper will present a successful solution to effectively predict and clear sand in a timely manner and at a lower cost in across the Shah Gas Plant and Access Roads area. The invention has been developed as a part of ADNOC Sand Accumulation (Phase 2) for ASG organization in collaboration with Siemens.
Integrated Techno-Economic and Life-Cycle Assessment of Subsurface Energy-Storage Technologies for Renewable Energy
Authors: Tayyib D. M. , Sekar L. , Okoroafor E. R. 
Published: November 2024

Abstract
The reliance on renewable energy in the modern energy mix is expanding due to two primary factors: the need to decrease dependence on fossil fuels and the imperative to lower carbon emissions. Integrating renewable energy sources into the grid is crucial for mitigating greenhouse gas emissions. However, a significant challenge associated with increasing reliance on renewables is the inadequate methods for effective storage of this energy, which is essential for minimizing curtailment and maintaining grid stability by balancing supply and demand. This study identifies the technical and economic feasibility of two potential storage technologies: subsurface heat storage and subsurface hydrogen storage. As a first step this study used the average energy curtailment data from the Energy Reliability Council of Texas (ERCOT) to demonstrate the applicability of these energy storage technologies. This study also quantifies the technical and economic feasibility of each technology using reservoir simulation by determining the subsurface withdrawal efficiency. It also determines the optimal storing option in terms of estimated efficiency, levelized cost of storage, and GHG emissions. Results showed that around 29-57% of the curtailed energy can be recovered through subsurface H2 storage, whereas around 6-17% can be recovered through synthetic geothermal storage. The levelized cost is between $102-115/MWh for H2 storage and $19-73/MWh for geothermal heat storage. The conclusion is that subsurface H2 storage can be a more promising technology for mitigating renewable energy curtailments from both technical and economic standpoint.
Ultra Mobile Solar Hybrid Solution for Mobile Rig Camps in Abu Dhabi
Authors: Grizi Ameen , Shadid Feras , Shamma Hassan , Al Hamlawi Imad , Baptista Luis , Mohammed Tariq 
Published: November 2024

Abstract
This paper presents the implementation and performance evaluation of a mobile solar-hybrid power system deployed by an onshore oil & gas operator in the UAE. The system uses an ultra-mobile, containerized solar solution to power mobile accommodation camps, traditionally powered by conventional diesel generators. Since November 2023, the operator has been using this system to power a mobile rig camp in a prolific field southwest of Abu Dhabi. The system comprises two 75 kWp solar containers (including inverters), a control panel (energy management system and data logger), and two diesel generators (one prime and one standby), with capacities varying according to load requirements over the operation duration.
The energy management system, developed in-house by the provider, maximizes solar utilization, and ensures efficient operation of all energy sources. The system has provided substantial benefits over its nine-month operation, primarily reducing CO2 emissions by 47% compared to diesel-only generators. This equates to approximately 262 tons of CO2 or around 100,000 liters of diesel saved. The containerized design enables rapid transport and installation, with mobilization times of under four hours. The hybrid system also lowers fuel consumption and maintenance costs, improving the economic viability of running the mobile rig camp.
Real-time monitoring is crucial to the system's safe and efficient operation, providing high reliability and uptime without requiring excessive onsite personnel. Compared to the previous diesel generator setup, the hybrid system's reliability is a significant advantage, eliminating frequent shutdowns caused by manual generator switchovers. Overall, the deployment of the ultra-mobile containerized solar-diesel hybrid power system has been successful, demonstrating significant CO2 emissions reduction and improved operational efficiency and cost-effectiveness. The lessons learned from this project highlight the importance of sustainable energy solutions for off-grid applications in the oil and gas sector.