bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wellsite Carbon Reduction with Improved Engine Load and Count Management
Authors: Auld S. , Kern S. 
Published: February 2024

Abstract
The energy industry's focus on Greenhouse Gas (GHG) emissions reduction requires solutions that are both cost effective and scalable across a global rig fleet (specific to a rig contractor) to reduce excess fuel and associated GHG emissions. A system was designed and implemented using existing assets without requiring complete refurbishment, to provide sustainable benefits, focused on the foundational concept of excess engine hour reduction.
One method to reduce drilling emissions is by reducing fuel consumption: specifically, by reducing excess engine hours for rig activities. Excess engine hours are defined as the measured time when more engines are running than necessary to supply a given load. Using engine load threshold data for optimal engine use is a universal solution to provide GHG emissions reduction in an efficient manner, not dependent on a rig type or specification. An engine management-based solution is efficient, removing the time-intensive task of isolating variables associated with a given rig activity.
Clear results were seen in both micro and macro studies by reducing underloaded engines throughout the well cycle. In a two-well comparison, focusing on excess engine hour reduction through engine management alone, the efficiency gains from Well 1 to Well 2 were 902 gallons of diesel and 9.2 tons of CO2e. Annualized, this is an equivalent 16,500 gallons of diesel and 181 tons of CO2e per rig. In a larger study, the primary goal was to decrease the amount of engine time in an underloaded state across the fleet to an under 30% target. Prior to program launch, 25% of the rig fleet regularly achieved the below-30% target. Roughly one year after launch, 48% of the rig fleet regularly achieved the below-30% target, nearly doubling initial metrics. Annualizing the benefits from pre-launch to post-launch with a rig fleet growth of 48% between the two analyses, an excess engine hour reduction of 166,744 hours was achieved, having a direct impact on fuel and GHG emissions reduction. The solution is now successfully deployed on a fleet of 98 rigs.
The improved baseline performance achieved with engine management as demonstrated in this example will allow for proper evaluation of additional technologies and drive fit-for-purpose solutions that solve for the outcome needs of the industry when grid or highline power is not readily or consistently available.
Bridging the Gap: A Pathway to Robust Rock Strength Modeling and Reliable Sand Production Risk Assessment in Thermal Steam Project
Authors: Riyami H. Al , Syabi M. Al , Zadjali R. Al 
Published: February 2024

Abstract
Thermal steam project has been successfully implemented in Haradh formation in A-East field in the south of the Sultanate of Oman. This project was developed outside the crest and expanded further to the north. Sand production control was identified as a potential risk; therefore, a sand prediction model was required to assess the rock strength at both hot and cold operating production conditions. Due to the large uncertainty in rock strength for Haradh at high temperatures, a dedicated fit-for-purpose geomechanics program was executed for an appraisal well drilled in the field. The main objective was to determine the strength characteristics of Haradh at room and elevated temperatures, which would help to assess the reservoirs stability during the thermal steam injection process. This paper outlines (i) the results of Geomechanical laboratory analysis, (ii) elastic and physical properties from log data and (iii) generated log-derived rock strength model.
Large rock volume XL-Rock Rotary Sidewall (SWC) coring was carried out in X-well across the full depth range of Haradh oil column. The Computerized Tomographic scanning images were used for quality control and selection of the best core plugs for testing. Unconfined compressive strength (UCS) tests were performed at atmospheric confining stress (confining pressure is zero) and "as received" condition at room (20-25 °C) and elevated (200 °C) temperatures to simulate the operation conditions during steam injection. Thin section petrographic and point counting analysis was conducted to study the impact of mineral contact on the UCS. Empirical relationships were established between core measured UCS and log data to develop UCS profile across Haradh formation.
UCS results show medium rock strength ~ 13 −17 MPa of Haradh sandstone at room temperature. As the test was performed at high temperatures, the UCS value shows a drastic drop in the rock strength of more than 50% reduction (range between 3.16 to 6.84) which might indicate a potential risk of rock failure at high temperatures. The comparison between the laboratory measured UCS and the profiles obtained from the empirical models show a reasonable match specially with the Petroleum Development Oman (PDO) correlation. The study results show that Haradh rock's strength may decrease during thermal steaming operation, which could potentially lead to reservoir instability and failure. A more detailed evaluation is recommended to assess this risk and investigate the impact of temperature induced stresses on sand production using FIST (Fully Integrated sand prediction tool) rock failure model.
When Machine Learning Helps to Understand a Facies Controlled Two Ways Tilted Contact in a Large Carbonate Reservoir
Authors: Robail Frederic , Sanyal Satyashis , Gazali Ismail Marzuki , Azudin Ahmad Nazmi B. M. Noor , Tabatabai Seyed Mehdi , Wulandar Ratih , Lubis Zulfikar 
Published: February 2024

Abstract
This case study presents an example of a large multibillion barrels in place carbonate reservoir where a two way tilted contact has been identified. Based on petrophysical analysis integrated with sedimentology studies and structural analysis, a tilted contact with two perpendicular directions (North-West / South-East and South-West / North-East) has been identified in this large structure. The mapped contact surface was found to be near parallel to the top depth structure, while the oil column thickness remained generally consistent throughout the field.
During a recent drilling campaign, new cores have been cut in several wells. These cores cover the entire reservoir section from reservoir top to reservoir base, as well as across the depths of the measured resistivity-based contacts. Thus, a complete sedimentological core description as well as routine core analysis and special core analysis are available both in the hydrocarbon and water legs.
Machine learning algorithms have been used here for two purposes. Firstly, using core plug permeability measurements to create a core based permeability model and then to propagate it throughout the field to the uncored wells. Secondly, using sedimentological core descriptions, a depofacies and a lithofabrics frameworks have been established and propagate to the entire field. This approach has been validated by means of production logs and correlation panels.
A good correlation between the permeability profile, the facies distribution and the resistivity-based oil water contact (OWC) location has been observed. This suggest that the reservoir facies control the two-way tilted contact in this reservoir. Additionally, based on the regional tectonic’ setting of the area, a structural tilt is envisaged to have been active in geological time. This has likely contributed to a certain extend to this two-way tilted contact.
The tilted contact orientation in two perpendicular directions identification has helped in sensitizing the hydrocarbon in-place and recoverable volumetric impact to support the present and future field development plan and the long-term sustainable production of this reservoir.
Reservoir Quality Prediction: MICP-Derived Microporosity Effects on Sonic Velocity
Authors: Baechle G. , Alkaba F. , Tudares N. Q. , Hursan G. 
Published: February 2024

Abstract
This study uses a sufficient number of core plugs with the objective to combine mercury injection pressure data for pore characterization with conceptional pore type models using sonic velocity. The plugs are analyzed to establish relationships between porosity, pore structure, permeability and log-derived sonic velocity. This paper combines two well-established methods for reservoir quality prediction: pore typing using sonic velocity and pore throat characterization using mercury injection capillary pressure (MICP) data.
Microporosity is known to be a significant parameter for permeability prediction. In our dataset microporosity relates to velocity at a given porosity. MICP derived pore throat parameters are linked to microporosity and to sonic velocity. Linking MICP derived petrophysical rock types through microporosity with poroelastic properties opens the potential to predict reservoir quality using sonic data at the log scale. Classifying MICP data by means of fraction of microporosity provides a geologically meaningful classification and interpretation of rock properties.
Quantifying the Influence of H2S Impurities on CO2 Storage Efficiency in Carbonate Reservoirs: An Experimental Findings
Authors: Razak A. A. A. , Saaid I. M. , Yusof M, A, M. , Zaidin M. F. , Zulkarnain N. N. , Amir M. I. M. , Sazali Y. A. , Habarudin M. F. 
Published: February 2024

Abstract
This study investigates the implications of Hydrogen Sulphide (H2S) impurities on Carbon Capture, Utilization, and Storage (CCUS) operations in carbonate reservoirs, with a specific focus on Field X in offshore Malaysia. The research examines the interaction between Carbon Dioxide (CO2) and H2S under reservoir conditions, aiming to better understand their impact on reservoir formation and geochemical interactions. The goal is to gain insights into storage design and predictive capabilities when dealing with impurities. Advanced analytical techniques, including ICP, RCA, XRD, and SEM-EDX, were used to analyze the mineral composition and physical characteristics of core samples from Field X. Experimental tests involved exposing these samples to CO2 with H2S dissolved in brine and aging them under reservoir conditions. The research findings indicate that the presence of H2S in CO2-dissolved brine leads to a reduced rate of dissolution of carbonate rock samples, potentially offering benefits for CCUS storage. These insights into CO2-H2S interactions in carbonate reservoirs can be valuable for optimizing CCUS storage strategies, ensuring long-term stability and security, particularly in offshore Malaysia.
Prediction of Pure Mineral-H2-Brine Wettability Using Data-Driven Machine Learning Modeling: Implications for H2 Geo-Storage
Authors: Ali Muhammad , Tariq Zeeshan , Mubashir Muhammad , Kamal Muhammad Shahzad , Yan Bicheng , Hoteit Hussein 
Published: February 2024

AbstractGreenhouse gases, particularly carbon dioxide (CO2), have the effect of raising the Earth's temperature. To combat this issue and reduce carbon emissions, it is advisable to shift towards the widespread utilization of cleaner fuels, such as hydrogen. The establishment of a global-scale hydrogen economy, coupled with hydrogen geological storage, presents a viable solution to meet the world's energy demands while accommodating peak usage periods. In geological hydrogen (H2) storage, the rock formation wetting characteristics are essential to regulate fluid dynamics, injection rates, the spread of gas within the rock matrix, and safety considerations. The wetting characteristics of minerals within the rock are significantly influenced by geological factors. To assess the wetting behavior of a mineral/H2/brine system under geo-storage conditions, innovative approaches have emerged. This research utilized a combination of advanced machine learning models, such as fully connected neural networks, adaptive gradient boosting, random forests, decision trees, and extreme gradient boosting to forecast the wettability characteristics of a ternary system comprising hydrogen (H2), brine, and specific rock minerals (namely quartz and mica). The predictions were made under various conditions, including different pressures ranging from 0 to 25 MPa, temperatures spanning from 308 to 343 K, and salinities of 10 wt.% NaCl solution. The machine learning models demonstrated remarkable accuracy in predicting mineral/H2/brine system's wettability (contact angles, advancing and receding). Incorporation of various experimental values have established correlations based on ML techniques. The performance and reliability of these models were rigorously assessed using statistical methods and graphical analyses. The deployed ML models consistently provided accurate predictions of wettability across diverse operational scenarios. Notably, the suggested model exhibited a root mean square error (RMSE) of 0.214 during training and 0.810 during testing. Furthermore, sensitivity analysis revealed that pressure exerted the most significant influence on mineral/H2/brine system's wettability. These ML model outcomes can be effectively utilized to anticipate hydrogen geological storage capacities and ensure the security of restraint in large-scale developments.
An Evaluation of Imaging-While-Drilling Technologies: A Comparative Study of Functionality, Applications, and Performance of Different Sensors
Authors: Manuaba Ida Bagus Gede Hermawan , AlHassan Mohammed , Taher Ahmed , Najrani Hussain 
Published: February 2024

Abstract
Most logging-while-drilling (LWD) measurements can resolve azimuthal changes around the wellbore and create borehole images, which are useful for well placement, formation evaluation, drilling operations, and production. The resolution of the images varies depending on multiple aspects of the sensor design such as vertical resolution, acquisition rate, and the number of azimuthal sectors acquired. High-resolution images are utilized for reservoir characterization, fracture identification, and sedimentological research, whilst lower-resolution borehole images are employed for well placement and geomechanics.
Multiple imaging sensors, including gamma ray, ultrasonic, micro-resistivity, and two different designs of density tool, were deployed in the same drilling bottom-hole assembly (BHA). The two density tools had different azimuthal resolutions (16 and 32 sectors), while the micro-resistivity sensor provided two different image resolutions, generating 1-in. and 0.4-in. resolution images with multiple detectors. More than 250 sectors, with a resolution of less than 0.2 in., were recorded by the ultrasonic imaging sensor.
Data was acquired in multiple runs with the same BHA configuration, providing insight into time lapse analysis, wellbore deterioration with time, and fracture propagation after pumping acid into the wellbore following a stuck occurrence.
The evaluation of multiple images acquired in different runs provided a valuable insight into the different sensors’ advantages and limitations. This study can be used as a comprehensive guide for the evaluation of LWD imaging tools.
A Comprehensive Analysis of Filter Cake Breakers for Non-Aqueous Drilling Fluids
Authors: Stamer K. , Baltaeva M. , Orlov M. , Wagle V. 
Published: February 2024

Abstract
Non-aqueous drilling fluids (NADF) have become widely used due to their ability to provide failure-free drilling in difficult conditions. During the drilling, the filter cake is being built on the wall of the borehole providing the integrity of the wellbore and preventing formation damage. However, filter cake can cause long-term bringing-in of a well and an increased value of the drawdown required for inflow stimulation. Hence, the filter cake has to be successfully removed in order to maximize the well's productivity. The goal of the research is to provide a comprehensive analysis of various formulations used for NADF filter cake removal.
NADF is typically formulated using oil as a continuous phase, brine as a dispersed phase, emulsifiers, wetting agents, and gellants. Depending on the reservoir, the filter cake may have a complex structure due to the particles’ intermixing with the emulsion to create the internal and external layers. Destruction of this system is an intricate task, particularly in horizontal and multilateral wells. An effective breaker must be able to separate the mud into component phases and simultaneously dissolve the weighting agents. The design of an effective treatment requires accounting for the mud composition, formation type, downhole conditions, and type of a completion. The variety of available solutions as well as their advantages and limitations are described in this article.
The results of the research demonstrate that state-of-the-art systems and technologies can be divided into several groups depending on the number of stages and the required alteration of the rock wettability. To dissolve the external filter cake built by the hydrophobic weighting materials the chelating reagents, acids or acid precursors are commonly utilized. An internal filter cake formed by the emulsion drops and emulsion blockage in the damaged zone can be removed by solvents, mutual solvents, de-emulsifiers or microemulsions. Modern eco-friendly technologies as well as multifunctional thermochemical fluids used for removing the barite filter cakes are also highlighted in the publication. It is shown that many factors affect the filter cake removal efficiency, including mud oil-water ratio, types of solids present and their concentration, salinity, and temperature. Furthermore, a preliminary assessment of breakers’ performance should be performed in a laboratory while considering the individual characteristics of each well.
Although many formulations have been introduced to remove barite filter cake in NADF, the need for a low-cost, compatible, and efficient breaker still prevails. Based on the research findings, a new thoroughly selected composition of chelates, surfactants, and additional reagents as a breaker with high de-emulsifying properties, and barite-dissolving ability is expected to be developed to break down the filter cake after completion of drilling with NADF.
Effect of CO2 Chemical Reactions on Rock Pore Surface Morphology – A Laboratory Study
Authors: Singer Gabriela , Ma S. Mark , Chen Songhua 
Published: February 2024

AbstractCO2 capture and subsurface sequestration (CCS) is a viable solution to reduce the greenhouse gas effect on global warming. It is known that CO2 in water chemically reacts with rocks during the process of CCS (injection, migration, plume, and long-term storage). The objective of this study is to better understand the dynamics of this interaction, and to develop measurements capable of monitoring changes of rock properties during CCS.As changes in rock properties originate from chemical reactions between pore-surface minerals and CO2, characterizing changes in pore-surface texture and geometry is essential for predicting subsequent changes of other rock properties relevant for CCS. As such, the methods used in this laboratory study include laser scanning confocal microscopy (LSCM) for measuring pore-surface roughness, Brunauer-Emmett-Teller (BET) adsorption isotherms for measuring the specific surface area, and nuclear magnetic resonance (NMR) relaxation for measuring pore-size, pore-connectivity, and surface-relaxivity (a function of wettability and fluid-surface interactions).In this study, five brine-saturated carbonate rocks (including three outcrops and two reservoir rocks) were exposed to supercritical CO2 (scCO2) under various ageing conditions. Specifically, we exposed the carbonate rocks to scCO2 under increasing pressure, temperature, and salinity, and measured LSCM, BET, and NMR after each of the total five ageing steps. By comparing with the initial non-ageing measurements, data indicate that the scCO2 exposure increases both surface-relaxivity and surface-roughness, particularly for the reservoir rocks. At the final step of ageing, the scCO2 exposure increases both pore-size and pore-connectivity for the reservoir rocks and some outcrops.Our findings may have direct impacts on planning and executing CCS projects, especially in carbonates. Changes in pore surface roughness and wettability can directly affect CO2 injection because it affects the reactive surface of the pores. Once significant surface erosion occurs, other macroscopic properties may change as well, as observed from the increase in pore connectivity in certain cases. Dissolution and precipitation change the pore-size and connectivity, thereby capillary pressure and permeability, which may also affect caprock's integrity. Our study shows that quantifying the changes caused by CO2 chemical reactions with rock minerals is crucial for CCS projects, including site selection and storage capacity assessment. Further, this study shows that NMR could be a valuable downhole tool to capture and monitor these changes, such as assessing changes of rock properties due to CO2-rock chemical reactions and contributing in validating dynamic chemical reaction models and help to adjust for prediction models.
OBM Resistivity Imaging in Formations with Wide Resistivity Range, Multi-Frequencies Acquisition to Identify Features of Different Characteristics
Authors: Kader Ramy Abd El , Khamry Ayman Al , Woldeamanuel Mandefro B , Gouda Mohamed 
Published: February 2024

Abstract
Several challenges were encountered to obtain good quality of high-resolution resistivity images in oil-based mud (OBM) borehole environment. Technology development incorporated innovative designs of multi-arm, multi-frequency resistivity imaging pads to mitigate some of these challenges. This article will demonstrate the achieved benefits of deploying two OBM wireline (WL) resistivity images in addition to ultrasonic imager, in a large and intermediate vertical borehole through mixed lithologies with wide range of Formations resistivities and to provide recommendations for future deployments.
Pre-planning is emphasized for achieving good results; expected lithologies, resistivity ranges, OBM components, etc. Accordingly, frequencies selection and required logging passes can be advised. During image acquisition, raw data processing takes place instantaneously to maintain real-time quality control and perform interactive changes as required for logging optimization. Customized composite plots are produced to compare between processed images from different frequencies to visualize the variable definition of borehole features between frequencies in ascending order. At this stage, dielectric effects on higher frequencies can be observed clearly when the Formation's resistivity range comes out of limits for these frequencies.
In different Formations resistivity ranges, Low-Resistivity-Low-Contrast (LRLC), medium and high, it was proven that implementing multiple frequencies from OBM resistivity imaging technologies significantly reduce the probability of missing the definition of fine features such as thin-bedding sequences or natural fractures those existed in Formations of wide resistivity range (0.2 ~ 1500 ohm.m). Multiple frequencies from OBM resistivity imagers plus one from the ultrasonic imager were processed, compiled and analyzed to conclude that using of multiple frequencies is far superior than single-frequency OBM resistivity imager in similar environment, confirming the need to combine technologies to cover wider range of measurement specifications and to urge the industry towards the innovation of a single new technology that incorporates wider range and number of frequencies covering the measurement range and required environmental corrections in one platform.
Eventually, OBM resistivity imagers of multiple frequencies deployment is becoming more proven approach after studying this case, and way important to achieve the deployment objective of high-resolution borehole imaging service(s) in OBM borehole environment. Future technology development is intended to correct for measurement artifact.