bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Decade of Multilateral Technology Installation Improvements Down Under
Authors: Cappiello Stefano , Pasicznyk Adam 
Published: October 2023

Abstract
Multilateral completions increase reservoir exposure while reducing the investment by minimizing the equipment and the installation time compared to two individual wells. multilaterals (MLT) wells in the Northwest shelf of Australia have been installed for over a decade now. An overview of these operations, well architectures, technology evolution, reliability and efficiency are discussed in the paper.
This paper reviews the custom solutions developed throughout the past decade illustrating not only the industry maturity, but also specific advancements in multilateral completion technology that were pioneered in the region. The study is focused on subsea multilateral campaigns, where multiple global and regional first installations took place in mature fields.
Operational and technological advancements were implemented throughout the campaigns based on lessons learned. Inaugural deployments featured pre-milled windows, inner-string based liner orientation methods, and a dedicated cleanout trip. Operational modifications and new technologies were introduced to significantly reduce installation time and costs.
The first multilateral installation completed in Australia by the service company was in 2006. Over several different projects with different operators in Australia, one particular system was the basis for successfully deployed variants, delivering over thirty productive laterals where mechanical and hydraulic integrity was achieved at each junction.
The study demonstrates how the continual advancement of technologies and efficiencies resulted in a reduction of MLT installation time by nearly half since the first system was installed. This encompasses not only new installations, but also infill re-entry applications as well. Additional cost reductions were realized with the introduction of trilateral well construction. This was accomplished by addressing and mitigating risks inherent to adding more junctions to the configuration.
This case study focuses on the offshore MLT well construction techniques and demonstrates how introducing both technology and efficiency changes can drive optimized time and costs amid oil price uncertainty. This paper also provides insight as to methodology for continually improving reliability of MLT installations, even while well complexity increases.
Elastic Inversion in Brazilian Offshore Pre-Salt Carbonates Context
Authors: Blanvillain P. , Painchaud Y. , Pernia-Soto L. 
Published: October 2023

Abstract
This paper presents a 3D seismic deterministic elastic inversion and classification study in an offshore Brazilian pre-salt carbonate field. Usually in this context, we carry out an acoustic impedance inversion studies because the elastic component – Vp/Vs or IS – often does not allow a sufficient lithology discrimination. This is unfortunate as it limits the petrophysical interpretation of the field. Indeed, a 3D elastic information is generally very useful for the reservoir characterization.
The studied field is a giant pre-salt field deep offshore Brazil (2100m of water depth). Platforms around the basin are associated to major transform zones and related to magmatic activity. The trap of the field is represented by a combination of the uplifted tilted faulted block, limited by a series of the NNE-SSW faults, on which the carbonate platform (reservoir) is developed. Here the lateral facies change rapidly from reservoir facies of the carbonate platform into muddy and shaly deep lake facies. The carbonate platform is limited by Ariri salt layer at the top and by shales of Picarras formation at the base. The reservoirs are represented by carbonate lacustrine deposits of syn-rift (Itapema formation) and early post rift (Barra Velha formation). The reservoir quality is controlled not only by process of sedimentation but also by strong multi-phase diagenesis and fracturing. Also on the field, important changes of the originally deposited sediments are related to hydrothermal diagenesis which lead to a specific cementation (dawsonite, silicification, dolomitization) and dissolutions resulting in the appearance of vugs, caves, connected conduits and "fractures' corridors" – big scale heterogeneities and secondary media. The complexity of the field is also complemented by the presence of intrusive rocks linked to several pulses of magmatic activity.
The objectives of this study were to characterize spatial repartition of the lithology in the reservoir and its porosity to assist to the interpretation and the reservoir characterization of the field. The field also has an intricate structure with four compartments and three different Oil Water Contacts.
The challenges on this project are linked to the complex structure of the field with the presence of highly structured magmatic intrusions below the salt and the mix of variable reservoir quality of carbonates difficult to interpret on seismic.
Development of a Rock-Based Geopolymer for Well Abandonment Applications - Utilizing Brazilian Rock Precursors
Authors: da Silva R. Ribeiro , de Oliveira Freitas J. C. , Moreira R. Peralta Muniz , Braga R. Martins , Khalifeh M. 
Published: October 2023

Abstract
This article focuses on the development and characterization of one-part rock-based geopolymer slurries utilizing Brazilian rock precursors for well construction and plugging and abandonment applications (P&A). The study presents the fluid-state and solid-state properties of these geopolymers, X-ray diffraction (XRD), and Scanning Electron Microscopy (SEM) to understand the precursors' microstructure and reaction level. The effect of temperature and pressure on compressive strength development was investigated. By altering these parameters, the study aimed to understand the impact of different environmental conditions on the strength development of the geopolymer material. Technological tests were performed according to API RP 10B-2. Compressive strength tests were conducted to determine early strength development and thickening time, and UCA tests were carried out. Post-curing, Retvied analysis through XRD was performed to examine microstructure and reactivity. Finally, fluid-state properties were also assessed, including thickening time and viscosity. The strength development of the geopolymers is observed to be time and temperature-dependent, as shown through ultrasonic strength data. The final product has a dense structure, and its long-term performance will require evaluation to determine its sealing capability and volume change as a barrier material. The research demonstrates the potential of rock-based geopolymers for well cementing and well abandonment applications using a Brazilian rock precursor.
Unlocking Uneconomic Reservoirs Through a Modified Design for the Tubing Pump for a Commingled Production
Authors: Eltoukhy Mahmoud 
Published: October 2023

Abstract
Artificial lift techniques have been utilized in the oil industry since decades. The main objective is to provide an extra energy to the fluids to be produced into the surface when the reservoir pressure is not capable to deliver the fluids naturally. Among these techniques, Sucker rod pump is still being used worldwide due to its simplicity in design, operations and maintenance. However, it still has some limitations in harsh environments like producing different zones.
For decades, Operators have been using commingled production as a valid alternative to produce mature fields to increase oil recovery. The benefits of commingling production from separate reservoirs are many. Among these benefits, it allows to produce from multiple reservoirs which may not be economic on their own, lower OPEX, less infill drilling activities and a sustained oil production plateau. There are different techniques in oil industry to handle commingled production such dual completion with ESP and gas lift.
In this paper, we will exhibit our modified design for the simple tubing pump. The new innovative design with a double acting movement in the same stroke will allow to produce from commingled zones without suffering from the pressure difference between the zones. During the downstroke, the fluids entered the pump plunger via the traveling valve while the fluids from annulus will fill the pump chamber above the main plunger via ports. Meanwhile, during the upstroke the fluid entered the pump barrel via the standing valve and the fluid from annulus entered the barrel will be lifted above the mandrel to production tubing via one way valve with a sleeve. This new design allows to increase flow area with the same pump size, and hence more flow rate.
This paper showcases a conceptual study that includes the principles and the physics behind the modified design for the tubing pump, which can be utilized as an economic alternative for the common techniques that widely used for commingled production.
Value of Downhole Drilling Data for Real-Time Formation Evaluation and Early Decision Making
Authors: Prasad Umesh , Wu Lei , Hanif Amer 
Published: October 2023

Abstract
Under the environment of complex wellbore trajectory, deviated wells, or lateral drilling, be it for oil and gas, geothermal or carbon-sequestration, the newly developed downhole sensors, data-transmission in real-time together with data-analytics has enabled utilize all information contained in weight-on-bit, rate-of-penetration, rotational speed, torque, effective mud-weight used, and drilling vibrations. The high-resolution drilling data helps us mitigate drilling dysfunction and complement formation logs. In some cases, when conventional log acquisition is not possible, downhole drilling data may become the only source for formation properties. The paper presents our investigations in the standalone use of downhole drilling data. The process evaluates formation properties and integrates with other petrophysical logs to improve real-time data quality and interpretation. Case studies are included from both lab experiments and field examples.
The current research efforts are encouraged by technological developments, in downhole sensors, which can now be included with the bottom-hole drilling assembly and used in in-situ acquisition of drilling data. We use downhole drilling data and consider both rule-based and machine-learning (ML) methods, to evaluate formation for lithological and geomechanical heterogeneities. A well from Gulf of Mexico is selected to apply the concept. Results are verified against established log-based formation properties estimation. In wells with high deviations, or complex trajectories, downhole drilling data is found to be more reliable compared to use of similar measurements made at surface followed by surface-to-downhole conversions. In the present work, we trained the system using 75% of downhole drilling data, together with measured vibrational and bending moment. The model was then applied in the remaining 25% of untrained intervals and demonstrated ability to predict formation properties with good correlation. The evaluation was done on memory-based data received after drilling, however, can also be implemented as automatic processing to support real-time operation.
Drilling data is always available, whenever a well is being drilled. Real-time formation evaluation, based on this information, provides the drilling engineers and geoscientists an additional resource which can be either standalone or complementary to log data. Downhole drilling data is also available early in time compared to LWD sensors typically placed several tens of feet behind the bit. Ongoing improvements in sensor specifications, data quality and interpretation methods, is promising especially for environments where conventional real-time logging is not feasible. For robust ML application, training data from a range of geographical regions and reservoir is included to ensure correct prediction in all scenarios.
Reducing Diesel Consumption and GHG Emissions Using Hydrogen in Drilling Rigs
Authors: Machado R. C. , Oliveira I. , Castro A. G. , Torres E. R. , Brito C. H. G. , Zanella I. Z. , Leonardi F. , Ayad S. M. M. E. 
Published: October 2023

Abstract
The energy industry is seeking to reduce its environmental impact and transition towards a low-carbon future. One way to achieve this goal is by reducing greenhouse gas (GHG) emissions associated with the operation of drilling rigs. This paper describes the Development of a product and a process to inject hydrogen in the engine inlet of a diesel motor generator, which acts as a combustion optimizer, thus increasing efficiency in diesel burning, and reducing diesel consumption and GHG emissions.
The project involves retrofitting a diesel engine with a hydrogen injection system, using hydrogen produced by demand through electrolysis and a control system. The diesel engine operates as usual, but the hydrogen system injects a small amount of hydrogen produced by demand into the engine's intake air. The hydrogen mixes with the air and fuel mixture, improving combustion and reducing emissions. The hydrogen also helps to reduce the fuel's ignition delay, allowing for more complete combustion and reducing the formation of particulate matter. An electronic control unit (ECU) controls the hydrogen injection system, which adjusts the amount of hydrogen injected based on engine load and other operating conditions. The ECU also monitors the engine's performance and adjusts the injection rate to ensure optimal performance and emissions reduction.
The paper presents the results of a feasibility study, which assesses the technical, economic, and environmental viability of the project. The pilot conducted in Ocyan's ODN I Drilling Rig, last year (2022) has shown some excellent results leading to up to 6% improvement in fuel efficiency and CO2 emissions reductions, up to a 31% reduction in carbon monoxide emissions and up to 34% reduction in hydrocarbon emissions. These results are aligned with studies that have shown that hydrogen injection can lead to significant reductions in GHG emissions and other pollutants. During the research and development phase ongoing now, the plan is to execute and study more specific emissions and comparison tests to ensure these reductions. The paper also discusses the challenges and opportunities associated with the adoption of hydrogen technology in the oil and gas industry and provides recommendations for future research and development.
The project is important for the energy industry because it demonstrates the potential of hydrogen technology to reduce emissions, improve efficiency, and support the transition to a low-carbon energy system. By investing in this project, the industry can play a leading role in addressing climate change and contributing to a sustainable future.
Subsea 3D Video Survey of Mooring Chains - Improving Safety, Effectiveness and Efficiency
Authors: Dumont A. , Vagata A. 
Published: October 2023

Abstract
Production of oil & gas using moored Floating Production Storage and Offloading (FPSO) units has been experiencing a significant growth. As of July 2022, there were 209 FPSOs in use around the world. In addition, there are many moored FSOs and CALM buoys. Moored facilities are located in many different operating areas, environments and water depths. This growth has resulted in a major challenge to operators, mooring component suppliers, regulators, and Class Societies to assure the integrity of these facilities. Mooring chains are safety-critical systems for FPSO and moored facilities in general. They are subject to significant environmental and structural loads as currents, waves, drag forces but also impacts, abrasion with the seabed or the fairlead. Failures in a mooring line can result in dramatic consequences for the safety, the environment, and the productions. Periodic inspections are mandatory and can be performed in air or in situ. Several techniques are available, with their advantages and limitations. This paper discusses the motivation and business driver for developing and implementing a new and cost-effective in situ inspection methodology. The approach is based on 3D video survey performed by inspection class ROVs and robotic crawlers that allows to gather critical integrity information in a safer, effective Due to the conditions and the geometrical configuration, the Subsea 3D Survey of Mooring Chains is challenging. However, by using advanced photogrammetry, and laser triangulation techniques (Video Laser Scan™ or VLS™), it is possible to solve such a challenge from simple ROV (Remotely Operated Vehicles) flights and robotic crawler runs when it comes to tiny spaces (Fairlead). The VLS™ sensor (HD camera and Laser Line Projector) is mounted on the ROV that flies along the chain: the laser line scans the links' surface, and four linear paths along the chain ensure 360 degrees of coverage. The ROV is in flying mode and needs to follow the chain at an average distance of about 1m. The output is a high-accuracy Point Cloud from which dimensions of the links can be computed, as well as the 3D mapping of anomalies such as corrosion pits. Examples are presented, and comparison is made between traditional and new inspection methodologies based on recent mooring chains' inspection campaigns to demonstrate the improvement of inspection effectiveness and efficiency.
Development of a Reliability and Maintenance Database System for Offshore Well Equipment in Brazil: MINERVA, Phase 1
Authors: Destri Alice Claussen , Bernardi Pavel Rodrigues , Lopes Manoela Teixeira , Machado Mario Marcondes , Oliveira Helton Luiz Santana 
Published: October 2023

Abstract
This report discusses some of the main challenges and opportunities in the development of a well completion equipment database system in Brazil. To improve the quality of reliability and risk assessments, a major oil field operator recruited a multidisciplinary team to design and implement a Reliability and Maintenance (RM) database system. The primary objective of the proposed solution is to prevent equipment failure and mitigate associated downtime in offshore operations. However, a significant challenge lies in the dispersion of relevant data across multiple sources, including websites, various data repositories, and diverse formats. To address this issue, the solution aims to collect and consolidate these dispersed data into a single, standardized database. The development process involved a comprehensive data science approach encompassing crucial steps such as data collection, cleansing, and standardization. The overarching goal was to strive for accuracy and data integrity. By establishing a centralized and structured database, the solution empowers decision-makers to access reliable and comprehensive data, ultimately improving the management decision process. As a result, a reliability database named MINERVA (MINEr of Reliability for Value Adding) was built with more than 15,000 well-years data (operating time). The main idea is to improve the quality of the risk and reliability assessments for, e.g., workover demand estimates, completion alternative evaluations, "what-if" analysis, and so on. Among the contributions from the efforts undertaken at MINERVA Phase 1, is the incorporation of knowledge for the industry that translates into savings in operating costs such as maximization of well reliability and availability, reduction of the carbon footprint of production operations by avoiding unnecessary interventions, reduction of workover duration and the need for spare parts and associated logistic costs.
Well Swapping and Conversion Optimization Under Uncertainty Based on Extended Well Priority Parametrization
Authors: Barros E. G. D. , Szklarz S. P. , Hopman J. , Hopstaken K. , Gonçalves da Silva J. P. , Bjørlykke O. P. , Rios V. , Videla J. , Oliveira R. , Hanea R. G. 
Published: October 2023

Abstract
Offshore field development activities are commonly constrained by the capacity of production facilities available at the platform. It is a challenge for practitioners to find the best development and operational strategies to maximize field production in the presence of such constraints. Additional difficulties are raised when the often large geological uncertainties inherent to field development activities need to be accounted for throughout the search for the best strategy. In this work we present how computer-assisted optimization can help practitioners tackle these challenges.
In this work, we focus on the particular problem of selecting the optimal subset(s) of wells to be subject to certain operational actions taking place throughout the field production life-cycle. We leverage robust and efficient field development optimization framework (EVEReST) based on stochastic gradients and its flexibility for customization to new types of decisions. We extend the mathematical parametrization based on a single set of well priorities, so far used to optimize time-static drilling order and well selection optimization. We apply it to multiple sets of well priorities which facilitate the formulation of the large combinatorial time-dynamic well subset selection optimization problem in terms of continuous control variables more suitable for gradient-based optimization techniques.
The extended method is applied to two different real-life field case studies based on an offshore heavy oil field. In the first case, we use the well priorities to determine how to optimally select and swap the 14 producers (out of a total of 18) to be put on stream to satisfy constraints on the available variable speed drivers (VSDs) to provide power to the ESP pumps required to operate the producers. In the second case study, we tackle the problem of converting producers into polymer injectors for EOR purposes. Firstly, simulation scenarios indicate that such conversion has a positive impact on the overall project business case. However, deciding which 2 wells (out of a total of 5) to convert into polymer injectors, combined with when and how much polymer to inject while respecting the limits of available capacity of polymer injection facilities, leads to a complex optimization problem.
In both case studies, optimization found improved and non-trivial strategies, resulting in significant increases in the economic objective function (+107 million USD and +318 million USD in terms of NPV) and providing new insights to asset engineers into the operations of the field. This showcases the strengths of the EVEReST framework to tackle real-life optimization problems accounting for complex constraints and uncertainties which are critical to deliver solutions of practical value to the asset teams.
Automatic Cement Evaluation Using Machine Learning
Authors: Itikawa M. A. , Ahón V. R. R. , Souza T. A. , Carrasco A. M. V. , Neto J. C. Q. , Gomes J. L. S. , Cavalcante R. R. H. , Ribeiro I. B. , Rocha J. M. S. , Carvalho C. P. C. , Lima L. B. 
Published: October 2023

Abstract
Cementing is an extremely important step in the well construction process. It has important objectives such as hydraulic sealing to prevent migration of undesired fluids from the formations and their collapse. One of the methods to verify the quality of cementat jobs is running acoustic logging tools such as CBL/VDL and ultrasonic and inferring zonal isolation by the interpretation of such data. This study aims to use machine learning techniques for automatic cement logs interpration. Cement logs of 25 wells were used as database. The logs responses have been classified in five classes according to the bond quality by specialized interpreters. These classified segments were used to train neural networks and other supervised machine learning models, such as random forests and k-nearest neighbor (KNN). Feature engineering is used in order to find new and high-performance features. The models were developed in a Jupyter environment using Python libraries. The best classifier has a simple accuracy of 61.4% and approximate accuracy (where the prediction is up to one class away from target) of 91.3%.