bluuebunny/crossref_metadata_2025 huggingface dataset:
Protectionnisme colonial et liberté générale à l’époque révolutionnaire
Authors: Destouches Didier
Published: April 2024

Cet article s’intéresse à l’origine du processus juridique et institutionnel aboutissant à l’établissement des règles présidant aux relations entre l’État central et les éléments périphériques de son territoire situé en outre-mer dans l’histoire des institutions françaises. Les seules recherches menées sur le sujet de l’histoire du droit public d’outre-mer sont relativement anciennes, voire incomplètes ou approximatives. Or les expériences constitutionnelles et administratives des régions ultra-marines françaises sont multiples au regard de l’histoire et peuvent être étudiées à la lumière d’un contexte politique, économique et social différent selon les périodes. Cette histoire permet alors d’éclairer les analyses actuelles portant sur l’adaptation des institutions françaises en outre-mer, en particulier dans les départements d’outre-mer où l’expérience de l’assimilation est la plus forte et la plus ancienne.
La place des outre-mer du Pacifique dans la stratégie française et l’architecture régionale de sécurité
Authors: Gravelat Caroline
Published: April 2024

La contribution de la France à la sécurité et à la stabilité de la région Pacifique répond prioritairement à des besoins nationaux et à une responsabilité de voisinage. L’action de la France dans le Pacifique s’inscrit dans une architecture complexe qui mêle acteurs infranationaux (les territoires français), nationaux (gouvernement de la République) et supranationaux (Union européenne) autonomes les uns par rapport aux autres. Ce maillage, par lequel chaque acteur participe, chacun dans son domaine de compétences, à l’architecture régionale de sécurité implique adaptation, coordination et nuance dans l’appropriation de l’action. Deux des trois collectivités françaises du Pacifique, jouissent en effet d’un tel niveau d’autonomie, qu’elles peuvent devenir membre d’organisations internationales, après accord de l’État, nommer des représentants auprès des États de la région et signer des engagements politiques, la seule limite étant la signature d’engagements internationaux juridiquement contraignants pour laquelle, elles doivent obtenir les pouvoirs de la République. Elles peuvent donc conduire leur propre diplomatie en quasi-liberté. Ces contraintes de « partage de souveraineté » amènent à s’interroger sur la place réelle des collectivités françaises du Pacifique à la fois dans les stratégies nationale et européenne ainsi que dans l’architecture régionale.
Effectiveness of COVID-19 Risk Communication Messages in Indigenous Languages and the Promotion of Safe Practices in Ondo State, Nigeria
Authors: Adeyeye Babatunde , Salawu Abiodun
Published: April 2024

This chapter examined the effectiveness of COVID-19 risk communication messages in indigenous languages vis-à-vis the promotion of safe practices in Ondo, Nigeria. The survey research design was used, and a questionnaire was randomly administered to 384 respondents in Akure, Ondo State. Findings showed that most of the respondents were exposed to COVID-19 risk communication messages and got their first information about it from social media. Furthermore, the study found that respondents were not receptive to COVID-19 messages passed across in indigenous languages. They prefer COVID-19 messages to pass across in the English language. The study recommended that there is a need to ensure that risk communication messages aired in indigenous languages are demystified in a way that the audience can easily understand and act upon. The use of indigenous languages should continue to be used and encouraged, especially for risk communication interventions such as COVID-19. This will go a long way in ensuring that the audience accepts it.
Untethered Pressure Sensor Conveyance for Bottomhole Pressure Measurement
Authors: Seren H. , Hillman T. , Zeghlache M. Larbi , Deffenbaugh M. , Naseer F. , Thiel Tim
Published: April 2024

Bottomhole pressures of wells are commonly used to evaluate reservoir characteristics such as permittivity and permeability and connectivity between wells. To measure bottomhole pressure, a sensor needs to be conveyed either through an invasive method such as wireline, or it can be permanently installed downhole. These methods can be costly. In this paper, we are introducing a new conveyance method using an untethered well logging tool. We used an untethered well logging tool that can autonomously move in the vertical parts of liquid wells by changing its buoyancy. It takes a small dissolvable weight to descend in a well, and at a programmed depth the weight is released to make the tool buoyant. The recorded data can be retrieved after the tool returns to the surface. We expanded this tool’s capability so that it can land at the bottom of the well and stay for a programmed time frame. To do this, the dissolvable weight was coated to delay the dissolving time during the logging which also eliminated exothermic heating due to the dissolution process. For the demonstration a 900-ft deep test well with 4-in casing was used that has no connectivity with the formation. The tool was programmed to release its weight 6 hours after the start of the logging. Since the tool moves around 0.35 ft/s speed, this provided more than 5 hours of time frame for continuous recording of the pressure and temperature at the well bottom. The tool was collected from the well 6.5 hours after the deployment and the data was downloaded. As expected, the pressure stayed constant during the test. A very low-cost conveyance method was demonstrated for pressure sensor placement at the well bottom.
Qualification of a Subsea Pump for Dense Phase Fluid Applications in Brazilian Deep-Water Pre-Salt Fields
Authors: Kus B. , Schneider L. , Bourne M. , Cunha L. S. , Machado H. , Bidart A. M. F. , Passarelli F. M. , Vieira A. J. M. , Spelta M. J. M. , Moura D. A. G. , Oliveira F. S. , Silva N. E. , Brandão A. A. T. E , Da Silva Campos R. , Da Silva L. C. T.
Published: April 2024

An extensive de-risking program was conducted to qualify the subsea dense gas pump project design. As part of this program, a subsea pump prototype, a back-to-back centrifugal pump, was designed, constructed, and evaluated using a dense CO2/N2 mixture, referred to as dense gas. This dense fluid has a gas-like viscosity, but a density closer to that of a liquid.

The pump prototype was evaluated at varying suction pressures ranging from 150 to 200 bar, up to a maximum discharge pressure of 350 bar. The machine was operated at a maximum speed of 6,000 rpm, delivering a flow rate of up to 700 m3/h of gas mixture. The composition and pressure of the working fluid was selected to simulate Brazilian Pre-salt field conditions at the seabed. A vertical integrated pump-motor unit with environmentally friendly barrier fluid (BF) was configured using radial centrifugal impellers in a similar fashion as a multiphase subsea booster, to pump the homogeneous dense mixture.

The main objectives of the test campaign were to validate the hydraulic performance prediction and assess the rotordynamic behavior of the pump when operated with a dense fluid. Additionally, a series of slug tests were performed to prove the robustness of the pump in case of the transient high-load scenarios. The pump passed all the required tests and demonstrated anticipated robustness, which is crucial for subsea operation. The measured hydraulic performance exceeded predictions at high-load, high-speed conditions, which may be partly attributed to the conservatism in the selection process.

The successful combination of hydraulic performance, robust rotordynamic behavior, and an efficient control strategy provides strong evidence for the viability and effectiveness of the current subsea pump design for dense gas application.
Comparison Between Coupled and Uncoupled Dynamic Analysis of Floating Offshore WTG Support Structure
Authors: Gupta A. , Desai A. , Sarada S. , Seo B.
Published: April 2024

This study presents a comparative analysis of hydrodynamics for floating offshore structures, with a focus on the coupled and uncoupled analysis methods for a floating offshore Wind Turbine Generator (WTG) support structures. The primary objective is to assess the impact of these two parallel methods on key parameters such as fairlead tension and platform responses. The hydrodynamic analysis performed for this study employs two distinct software platforms, OpenFAST by NREL (National Renewable Energy Laboratory) and MOSES by Bentley, and highlights the effects of using coupled and uncoupled methods for response characteristics of the mooring lines. The authors conducted a similar study on the fixed offshore WTG support structure. This study established a benchmark methodology for the industry to calibrate uncoupled analysis to facilitate the exchange of information between turbine manufacturers and substructure designers within the restrictions of intellectual property rights. The study proposes checks and balances to verify intermediate outputs at various stages of design development. (Gupta, et al. 2023).In this study, VolturnUS-S reference floating offshore wind turbine semisubmersible designed by University of Maine along with International Energy Agency (IEA)-15- 240-RWT 15 megawatt (MW) reference wind turbine is used for the analysis. For the coupled analysis, an integrated global model of the floating hull structure with a WTG is modeled in OpenFAST and the coupled effect is captured by combining the hydrodynamic and aerodynamic responses. For the uncoupled analysis, response is generated by combining the hydrodynamic forces calculated in MOSES with aerodynamic forces using the AeroDyn module from OpenFAST. Results from both analyses are compared and presented in the paper.The coupled analysis provides a comprehensive representation of the system's behavior, capturing intricacies of the coupled behavior of the integrated model. In contrast, the uncoupled analysis simplifies the system but may potentially overlook vital coupling effects. The study contributes to a deeper understanding of the coupled and uncoupled analysis methods and their implications while providing valuable insights to engineers for the design process with respect to the varying effects of these methods on dynamic behavior of the integrated system.
Feasibility of Steel and HDPE Sea Water Intake Risers for Deepwater Applications
Authors: Mercan B. , Volk B. L. , Campbell M. , Guerin P.
Published: April 2024

There is a growing desire in the offshore oil and gas industry to lower CO2 emissions from operations, especially in FPSOs and FLNG units. One method to lower CO2 emission is to reduce power consumption by improving the cooling system so that it utilizes colder water from deep sea. Traditionally, Sea Water Intake Risers (SWIRs), which are usually made of reinforced rubber hoses, are used to supply water from water depths up to 150m to the topside, resulting in an in-take temperature of at least 15°C. Nowadays, many operators have been trying to reach colder water (5-7°C) with target SWIR depths up to 700 m in order to support emission reduction efforts. However, there are many design and material restrictions to achieve this goal. Therefore, this paper focuses on the feasibility for steel and HDPE SWIR configurations for deep sea applications (up to 700m).

Conducting a site-specific feasibility assessment at early design stage plays an important role in selecting an optimum SWIR configuration. The main pipe of the SWIRs is generally made of reinforced rubber, steel, or high-density polyethylene (HDPE). The SWIRs are installed in a free hanging configuration at the keel or on the sides of the FPSO. Their design can be challenging for deep water applications due to harsh environmental effects (i.e., wave and current). Interference with adjacent structures such as production risers or mooring lines can make their design even more complicated.

In order to investigate the feasibility of 350 m and 700 m SWIRs, nonlinear finite element simulations are performed using HDPE and steel pipes for a conceptual field. The steel SWIRs may provide more confidence in long term reliability as steel is a conventional material for dynamic pipelines (e.g., production risers), but can lead to weight and fabrication constraints for deep water applications. HDPE is neutrally buoyant and eliminates weight restrictions but is also prone to creep, large displacements, and connection challenges.

Today, there are many SWIRs in service, operating up to 150 m water depth and their design and operational requirements are well known by the oil and gas industry. Pumping sea water at depths greater than 150 m is a significant advancement for the industry as deeper SWIRs provide colder water and further reduction in the CO2 emission of FPSO's cooling systems. This paper focuses on the challenges and design limits for deep SWIRs (350 m and 700m) made of steel or HDPE.
Exploring the Potential of Laser Technology in Oil Well Drilling: Recent Advances and Future Recommendations
Authors: Gowida Ahmed , Elkatatny Salaheldin
Published: April 2024

Conventional rotary drilling techniques employed in crude oil and natural gas extraction present notable challenges and financial burdens. To mitigate these obstacles and minimize drilling expenditures, oil enterprises are investigating innovative cost-saving approaches. Laser technology has emerged as a non-invasive alternative to traditional methods, garnering attention within the oil and gas sector. This study assesses the feasibility of laser drilling as a promising departure from rotary drilling practices. The research undertakes a comprehensive examination of global studies on the utilization of lasers in oil and gas well drilling, providing insights into the technology's potential and offering recommendations for its practical integration in the oilfield. Extensive lab-scale experiments have showcased the proficiency of contemporary laser models in spalling, melting, and vaporizing various rock formations, ranging from Berea sandstone to highly resilient granite and basalt. Analyzing the rate of penetration against the required specific energy under diverse conditions facilitates an assessment of the technique's efficacy. Experimental findings indicate that fluid saturation within drilled rock does not impede the drillability rate. Advantages over conventional methods include heightened penetration rates, reduced tripping, casing, and bit costs, improved well management, and enhanced side-tracking capabilities. Consequently, laser technology promises to facilitate sustainable field operations, offering manifold benefits in operational efficiency, cost reduction, and environmental preservation. Nevertheless, technological challenges such as borehole cleaning, well control, beam downhole delivery, and complex formation conditions necessitate further exploration. The development of laser-assisted drill bits and downhole laser drilling machinery holds promise with advancing laser technology and sustained research into the technique's viability from both technical and economic standpoints. Crucial technical recommendations for laser drilling technology in the oil and gas industry encompass conducting feasibility studies, investing in research and development, validating technology through field trials, prioritizing safety and environmental concerns, performing cost analyses, instituting training programs, ensuring regulatory compliance, fostering collaboration and knowledge exchange, and continuously monitoring and enhancing performance. Adhering to these recommendations enables the industry to optimize drilling efficiency, curtail costs, and champion environmental stewardship, thereby advancing sustainable practices in oil and gas exploration.
Application and Experience of Hydrogen Deoxidizers in Seawater Deoxygenation Systems
Authors: Isdahl O. M. , Shamshiri S.
Published: April 2024

The scope of the research presented in this paper encompasses over 25 years of cumulative experience in employing hydrogen deoxidizers within water deoxygenation process systems. Seawater is injected into the system to strip the O2 from water by means of inert nitrogen gas. In these systems, the nitrogen stripping gas is circulated in a closed loop and regenerated over a chemical catalytic reactor, where a purity of at least 99.995 % is achieved. This paper presents empirical data derived from the operation of these systems.

A test system has been purpose-built to leverage several years of experience gained from hydrogen-fueled water deoxygenation in analogous onshore systems, with the aim of making it applicable to a new seawater deoxygenation system. This system is designed to purify a nitrogen stream, which is utilized to remove oxygen from seawater. Consequently, the nitrogen stream initially contains oxygen, and it is reused for the deoxygenation process, necessitating the removal of oxygen. The elimination of oxygen occurs within the hydrogen deoxidizer by introducing hydrogen upstream of a reactor equipped with a palladium catalyst. Hydrogen and oxygen react to produce water. The gas stream is driven by a liquid jet compressor, and the research presents operational procedures encompassing the control of hydrogen levels in the gas stream, control system considerations, safety protocols, and the regulation of other process variables, such as temperature, both upstream and downstream of the reactor. Notably, nitrogen shares similar thermal properties as hydrogen, and the reaction characteristics within such a reactor closely resemble the reaction in deoxo-reactors for deoxygenation hydrogen in Alkaline hydrogen production by electrolysis.

Results from hydrogen deoxidizer performance will be presented together with design considerations for generic hydrogen deoxo-reactors. Historically, this process has been driven by methanol offshore, and the paper will explore the feasibility of offshore on-demand hydrogen generation for the deoxo-reaction and evaluate alternatives for the supply of hydrogen such as storage solutions.

The novelty of the research is the combination of hydrogen deoxo-reactors with other process streams in combination with the seawater deoxygenation process.
Hybrid Structural Health Monitoring of an FPSO: Measuring Stress at Un-Instrumented Structural Details
Authors: Andoniu A. , de Lauzon J. , Pidery K.
Published: April 2024

Well designed and implemented Asset Integrity Management strategies are key to ensure safe operations and high availability of assets. In a world where data is king and data-driven decisions are becoming the norm, it will be difficult to imagine such strategies without the extensive use of monitoring technologies.

In the past years, Bureau Veritas has developed a hybrid Structural Health Monitoring technique that combines strain gauge measurements with state-of-the-art hydro-structure simulations. At the core of this approach lies the conversion matrix method: by projecting the structural response on a carefully chosen basis of distortion modes, a relationship can be found between any physical quantities related to hull deformation. In this manner, stresses anywhere on the structure, including un-instrumented structural details, can be expressed as a function of stresses at only a few instrumented locations.

However, accurately reconstructing structural response at locations where local effects are present can be challenging in all types of hybrid monitoring methods. This paper aims to show that these difficulties can be overcome, and the conversion matrix method can be successfully applied to reconstruct the local stress response at side shell stiffeners of an FPSO. Several sensor configurations used as input in the conversion matrix are tested and discussed. Validation is performed by comparing thousands of hours of direct sensor measurements with reconstructed stress time histories. The results show consistent improvement compared to virtual monitoring which is exclusively based on numerical simulations using encountered sea states.

Hybrid Structural Health Monitoring is the key to cost-effective monitoring. By leveraging the power and flexibility of numerical simulations, the capabilities of direct measurements are expanded to reach the entire structure, even at un-instrumented locations subjected to local effects.
Direct Lithium Extraction from Geothermal Brines: The New Oil
Authors: Lebit Hermann , Brunner Benjamin , Kharitonova Natalya , Deemer Eva
Published: April 2024

The energy transition is an inevitable global development driven by geopolitical, environmental, economic and societal factors. It will fundamentally change how we access energy resources and how we will rebalance the growing demand in critical commodities.

The global mobility sector consumes about 2/3 of the world crude oil production, which stands currently at or above 105 million barrels of oil per day (mmbopd). Even a minor reduction, for instance by increasing the electric vehicle fleet, would reduce greenhouse gas emissions but further stress our power grids along with an increasing demand in critical minerals, required by clean tech manufacturing. Industry strategies and technology developments have to address this conundrum.

Renewable energy sources already significantly contributing to the domestic electricity grid (13% in US in 2021) but are dominated by intermittent resources like wind and solar energy, whereas dispatchable, clean energy resources are neglected. The potential of dispatchable geothermal energy is undisputed, though challenges in subsurface risk assessment, completion technologies, upfront investments and lengthy permitting processes impact the economic potential of this technology.

Lithium is the key critical mineral in clean tech, particularly for batteries in the mobility sector due to its excellent energy density to weight ratio. Environmental impact of invasive lithium mineral mining or large evaporation ponds can be avoided by Direct Lithium Extraction from brines. It is a valuable solution particularly when deployed in proximity to mature hydrocarbon basins, attributed to a wealth in subsurface data, existing infrastructure, and qualified human resources. DLE technologies are facing some challenges in terms of freshwater usage, the application of chemical agents, excessive land usage and reliance on external energy supply. Finally, not every brine chemistry is suitable for the envisaged DLE technology.

Direct lithium extraction based on electrodialysis employs ion-selective membranes in a clean, emission free process. The technology is robust and takes advantage of successful membrane applications at multiple desalination plants around the world. Along with battery-grade lithium the electrodialysis produces green hydrogen, outputs freshwater and sequesters CO2 as by-products. When combined with a geothermal power generation the technology uses onsite energy and the produced brine in a clean and environmentally friendly process.

Lithium-rich reservoirs with a favorable geothermal signature have been reported from mature hydrocarbon basins across the United States and their direct lithium extraction offers attractive economics, given the growing lithium demand forecasted for the next decades. The operations are 100% green and self-sustainable when combined with novel low enthalpy geothermal power production technology. It opens a new running room to rejuvenate mature hydrocarbon basins into energy super basins.
Reducing Carbon Footprint by Using Fiber Reinforced Polymers (FRP) in FPSOs
Authors: Eves S. , Souza G. G. , Filho D. F. , Neto C. Jarreta
Published: April 2024

Fiber Reinforced Polymer (FRP) materials, including structural products and Glass Reinforced Epoxy (GRE) pipes, offer significant carbon footprint reduction when compared to traditional steel alternatives. This is because of the lower energy requirements needed for manufacturing and the lower energy use throughout the product's service life cycle. Global warming and the energy crisis make the use of FRP an attractive material of choice because its use results in less carbon dioxide released to the atmosphere.

Climate change affects our competitive landscape in many ways. Businesses face higher raw material prices, rising energy costs, and increasing awareness of manufacturers' and suppliers' environmental impact. Companies that focus on managing and mitigating their carbon footprint will have a competitive advantage over rivals in a carbon-constrained future. They will also be able to conduct their operations in an environmentally sustainable way.

The focus of this paper is to compare glass-reinforced epoxy (GRE) pipes and FRP offshore handrails with their steel alternatives, to illustrate the relative energy necessary to manufacture, transport, install, use and "through life maintenance" of the products. The critical success factors of FRP with respect to their carbon footprint will be highlighted to advance the case for this type of material in the offshore industry.

This paper is development on an original paper by NOV authors in this paper which includes new supportive technical data and research analysis put in place by two major industry operators MODEC and PETROBRAS.
Observations of New North Brazil Current Rings Profiles Offshore Guyana
Authors: Gosain Gagandeep , Schiller Rafael Vergara , Esenkov Oleg E
Published: April 2024

The North Brazil Current Rings (NBCRs) are a dominant phenomenon in the Atlantic Ocean offshore Guyana, which introduces substantial challenges and risks to offshore activities. Gaining a comprehensive grasp of the vertical current structure and variations linked to NBCRs is important for design and safe operations in the region. This study addresses the intricate attributes of NBCRs, utilizing data acquired from two deepwater moorings offshore Guyana. These moorings, equipped with current measuring instruments, were stationed along the pathway of NBCRs with the goal to capture their dynamic behavior and inherent variability.

One mooring was deployed in the water depth of about 1600 meters for 18 months. During this time, a total of seven NBCRs were observed, which were sorted into distinct categories based on their temporal and vertical characteristics. Four of these rings displayed surface current intensification, with peak near surface currents reaching 1.62 m/s. These rings were confined to the uppermost 200 meters of the water column. Diverging from this pattern, two rings exhibited a distinctive attribute—both surface and subsurface intensifications—with peak subsurface currents reaching ~1 m/s at a depth between 200 and 300 meters. Finally, one ring lacked the typical surface intensification and only exhibited subsurface intensification (currents reaching ~ 1 m/s at 300m below the surface). Throughout the measurement period, a prevailing southwesterly-directed reversal current persisted within the lower part of the water column.

The second mooring was positioned in the water depth of around 1850 meters. Its 12-month deployment period overlapped with the final year of the first mooring’s deployment, therefore this secondary mooring witnessed the occurrence of four rings observed by the other mooring. The observations confirmed the occurrence of the distinctive current profiles: two rings with surface plus subsurface intensification and one ring with subsurface intensification only. The second mooring also demonstrated the spatial and temporal variability of those rings.

This study’s significance extends beyond mere rings’ identification and description, unveiling the presence of novel current profiles with simultaneous near-surface and subsurface intensifications of comparable magnitudes. Additionally, it brought to light increased subsurface current speeds and distinct temporal behavior of these currents. These findings demonstrate the need for continuing measurements and modeling of circulation in the area to better understand and predict the events.
Use of Distributed Buoyancy as Lateral-Buckle Mitigation in High-Pressure High-Temperature Flowlines
Authors: Brunner M. S. , Desiraju A. , Ferdous R.
Published: April 2024

The use of distributed buoyancy modules as a lateral buckle mitigation device in High-Pressure High-Temperature (HPHT) flowlines requires consideration of a range of parameters to ensure a successful solution. An investigation into several of these parameters and their impacts on lateral buckling behavior is explored.

Buoyancy module spacing, the submerged weight in buoyancy sections, the buoyancy section configuration and length, and soil-pipe interactions at end modules are explored via the finite-element method. Sensitivities on these parameters for a single pipe diameter are explored as they relate to the lateral buckling behavior and associated industry-imposed limit states.

A rigid 8-inch HPHT production flowline is investigated for each of the parameters described. Finite-element models are used to investigate the lateral buckling behavior in virtual-anchor-spacing (VAS) models.

The VAS modeling of various distributed-buoyancy system parameters provides results that confirm the importance of adequately assessing these parameters in the design process.

VAS modeling demonstrates that buoyancy-module spacing, and buoyancy-section submerged weight, configuration, and length can all materially impact lateral buckling behavior and flowline integrity. It is found that each of these parameters needs to stay within a certain range for satisfactory performance, based on industry guideline VAS acceptance criteria and model stability, and going outside that range can yield unreliable and potentially risky lateral buckling behavior.

Ranges for the various parameters used in the design of distributed buoyancy sections are offered that will help ensure a robust and reliable distributed buoyancy solution.
Innovative Drilling and Completion Technologies for Economic Development of Offshore Unconventional Heavy Oil Thermal Recovery
Authors: Huo Hongbo , Zhang Xiaocheng , Zhang Lei , Hou Xinxin , Lin Jiayu , Chen Kejin
Published: April 2024

Bohai Oilfield is rich in unconventional heavy oil reserves where the viscosity of formation crude oil is more than 50000 cP and mobility are poor. To produce heavy oil from formation to the surface and transport it to processing terminal is recognized as a worldwide challenge, especially for offshore oilfield for development cost.

Taking the development idea of "Overall deployment, Step-by-step implementation, and Test first" for technical research, the pilot test of thermal recovery was successfully carried out in Bohai Oil fields for the first time. Facing well head elevation and annulus pressure build up problems caused by high injection temperature (350°C), the low-density cementing slurry system is developed to ensure the cementing quality; Casing material and sand control method are optimized and selected to ensure wellbore integrity and sand control effectiveness, and other down hole safety control tools have also been optimized for high pressure and temperature.

The results show that after 28 days of bath at 350°C, the uni-axial compressive strength of the newly developed cement stone can basically be stabilized, which indicates that the cement stone has good high-temperature stability and well head evaluation problems have been mitigated. The proposed injection-production jet pump integration process is that the heat injection process and the production process use one set of production strings to realize the efficient connection between heat injection and production, and the operating cost is reduced. The long-term sand control technology for thermal recovery wells has been proposed, and 8 rounds of field tests have been completed with the sand content of the produced fluid is less than 0.3‰; The high-temperature down hole safety control system including high-temperature down hole safety valve, high-temperature thermal production packer and other key tools have been developed to build a safety barrier.

These technologies have been successfully applied in Bohai Oilfield, helping Bohai Oilfield achieve a breakthrough in the large-scale and economic development of ultra-heavy oil.
AI-Based Cement Bond Quality Assessment: A First Step for Optimizing P&A Design
Authors: Correia Tiago M. , Camerini I. G. , Hidalgo J. A. S. , Ferreira G. R. B. , de Souza L. P. B. , Rodrigues A. S. , Penatti J. R. R. , Braga A. M. B. , Almeida R. V.
Published: April 2024

As decommissioning operations continue to expand, the challenges associated with evaluating the integrity of the cement layer and its bond to casing and formation become more pronounced. Ensuring hydraulic isolation of the wellbore from the surrounding environment is crucial before permanently sealing the well. However, the current methodology relies on the expertise of specialists who interpret extensive and intricate data obtained through logging operations. Recognizing the challenges inherent in cement evaluation, Ouronova, in collaboration with Repsol Sinopec Brazil, is developing a computational solution to help specialists interpret cement integrity logging data. Simultaneously, the developed tool aims to assist operators in optimizing the planning and management of decommissioning campaigns. The innovative software employs machine learning techniques that have exhibited significant promise in enhancing accuracy, reliability, and efficiency in the analysis of cement sheath integrity. Thus, the objective of this paper is to present some results obtained with the software by using Convolutional Neural Networks to predict the cement condition in two wellbore regions. The acquired dataset was used to generate Variable Density Logs diagram and plots here referred to as 2D Combined Signals, which were used as inputs to train the model. The main results indicate good accuracy in predicting the cement condition using the Variable Density Log and the 2D Combined Signals. In special, the latter showed to be a more promising option because its accuracy value tended to be more stable as the database was increased, in comparison with the Variable Density Log case. As a metric for the comparisons, the Balanced Adjacency Accuracy was used. For the results based on the Variable Density Log, we found a value of 0.810, while for the ones based on the 2D Combined Signals, we found 0.958.
Assessment of the Safety of Fishing Using Various Types of Fishing Gear in California Offshore Wind Lease Areas
Authors: Stahl C.
Published: April 2024

More than 300 offshore wind hull and mooring designs have been reviewed by classification societies. With the recent auction of lease blocks offshore of California, five offshore wind developers have site control and are evaluating the various hull and mooring concepts. Members of the fishing industry are interested in the potential effects of these future wind farms on their ability to fish safely within the leased areas. The following paper investigates the effects on fishing risk from the range of floating foundations currently being proposed by designers and includes: the implications of mooring design, turbine spacing, and the depth of array cables.

The implications of design choices on the safety of specific fishing gear are discussed. For example, interconnected mooring lines within 25 m of the surface present challenges for midwater trawling. The various hull and mooring concepts pose different levels and types of risk. For instance, a tension leg platform (TLP) with taut mooring lines has a lower likelihood of contact with fishing gear than a semi-submersible hull concept with catenary mooring lines. The TLP concept encapsulates much less underwater volume and has a smaller footprint on the seabed. In addition, TLP mooring lines are anchored to the ocean floor without significantly diminishing underwater clearance for fishing between turbines.

In addition to hull and mooring design, other aspects discussed are turbine spacing and the depth of the array cable. These three aspects provide a comprehensive perspective on how floating offshore wind may affect fishing safety in the waters offshore of California.
Horizontal Capacity of Suction Anchor with Retrievable Cap in Clay for Floating Wind Turbine
Authors: Wang H. , Wang Y. , and Pisanò F.
Published: April 2024

Recently, the offshore wind industry is transitioning from the fixed-bottom in shallow waters to the floating in deep waters. This shift requires station-keeping anchors to stabilize turbines. Maximizing the cost-effectiveness and installation efficiency of anchor foundations is critical for project success. Suction anchors offer an efficient installation method by creating an underpressure to penetrate the seabed without noise from hammering like driven pile anchors. This foundation concept, well-established in the oil and gas industry, holds promise for floating offshore wind applications. Traditionally, the top cap is fixed on the suction anchor after installation to provide a sealed condition inside for better vertical holding performance. However, in the case of a catenary mooring system in soft clay, where horizontal loads dominate, the conventional fixed top cap may not be necessary. Instead, a retrievable top cap can be designed, offering cost savings and ensuring full embedment of the anchor in the seabed, enhancing its capacity, and mobilizing more soil in deep areas. This study presents a series of numerical modelling to investigate the horizontal capability of the suction anchors in clay with retrievable top caps. Comprehensive numerical simulations were performed, which were validated first against the existing studies in literatures for traditional suction anchor with fixed top cap. A parametric study was then carried out to assess the effects of the retrievable top cap length, anchor length to diameter ratio (L/D), padeye location, and loading angle on the anchor horizontal capacity. Consistent with the existing studies, the failure mechanism of horizontally loaded suction anchor change with the padeye location, which transforms from a rotation failure to horizontal translation failure as the padeye location increase from seabed to around 0.6L (anchor length) and provides the highest horizontal capacity, although it should be noted that the padeye location is also affected by the loading angle. For the anchor with retrievable top cap, almost the same horizontal capacity was observed when the L/D ratio is larger than 1. In addition, when the retrievable top part extends to upper part of anchor, a higher capacity factor can be obtained due to the increased embedment and the mobilization of deep soil. Compared with the anchor with fixed top cap, the optimum padeye location of anchor with retrievable top part will also change to a shallower depth at around 0.5L.
Reducing the Environmental Impact of Seismic Acquisition While Improving Operational Efficiency by Incorporating New Technologies
Authors: da Silva A. A. C. , da Silva R. C. , Lopez J. L. , Grandi S. , Cortes P. N. , Apolonio F. A. , Ramos Filho W. L.
Published: April 2024

Three R&D initiatives in seismic data acquisition are presented focusing on the reduction of environmental footprint while reducing the operational cost and increasing the efficiency in offshore field operations. The first initiative is the development of a new seismic sensor that can remain on the seafloor for up to five years, the On Demand Ocean Bottom Node - OD OBN (Lopez et al., 2023), helping to decrease the cost of seismic monitoring surveys. The second initiative is a new type of seismic source with lower environmental impact, the Marine Vibrator, which improves the usage of the available energy of the seismic source within the most useful frequency band for seismic acquisition, suppressing higher frequencies potentially harmful for marine mammals (Wartzok and Ketten, 1999). The third initiative is a pilot 3D seismic acquisition in deep-offshore Brazil using fiber optic cables, originally installed on the seafloor as part of a Permanent Reservoir Monitoring (PRM) system, which will be interrogated using Distributed Acoustic Sensing (DAS) while recording shots from a seismic streamer vessel present in the area. It is expected that the 3D seismic data acquired in this manner will offer a good understanding of the potential for DAS application for seismic data acquisition using fibers laid on the seafloor, considering the fiber's limitations in sensitivity and angular response. In addition to conventional applications for reservoir monitoring, these technologies are promising for applications linked to the energy transition, such as Carbon Capture and Storage (CCS) projects, where the expected low commercial value of the sequestered CO2 requires low-cost monitoring methods to be affordable.
Numerical Study on the Impact of Advanced Phenomena in a Fractured Carbonate Reservoir Subjected to WAG-CO2 Injection
Authors: Menezes D. E. S. , Botechia V. E. , Schiozer D. J.
Published: April 2024

Advanced phenomena related to water-alternating-gas (WAG) injection are usually neglected in numerical simulations. This work evaluates the impact of different physical phenomena on field indicators, considering a typical pre-salt carbonate reservoir (UNISIM-II-D-CO, a dual-por dual-perm compositional case) subjected to WAG-CO2 injection. Additionally, the computational cost incurred by each of these phenomena is evaluated, since it represents a great challenge in optimization and probabilistic studies. The following phenomena are evaluated considering a nominal base case: (i) matrix-fracture transfer calculation, (ii) relative permeability hysteresis, (iii) CO2 and CH4 solubilities in aqueous phase, (iv) diffusion, (v) numerical dispersion control models, and (vi) velocity-dependent dispersion. CO2 and CH4 solubilities in the aqueous phase, as well as molecular diffusion, did not have a significant impact on field indicators, but they increased simulation runtime more than two times. Matrix-fracture transfer modeling was the most impactful factor, followed by hysteresis and velocity-dependent dispersion. Therefore, the impact of these phenomena was also investigated in a probabilistic approach, considering an ensemble of 197 geostatistical scenarios under uncertainty. Risk curves revealed that the advanced matrix-fracture transfer models improve sweep efficiency. This effect is mainly due to gravity force which acts as a driving mechanism for the oil moving from the matrix to fractures. The capillary effect, in turn, was small compared to gravity. The impact of dispersion and hysteresis on risk curves were smaller than the effect of matrix-fracture transfer modelling. However, these phenomena are particularly interesting in UNISIM-II-D-CO due to the presence of Super-K facies. Hysteresis, when applied to low and high permeability layers, reduced gas mobility and, consequently, the gas produced, contributing to the NPV for most models under uncertainty. On the other hand, the velocity-dependent dispersion mainly affected fluid flows in the regions adjacent to Super-K layers, promoting better oil recovery. The inclusion of advanced phenomena related to WAG-CO2 injection can hold importance when modeling fractured carbonate fields, like those found in the Pre-Salt in Brazil. Nevertheless, computational costs might make their inclusion impractical in full-field simulation models employed for optimization and probabilistic studies. In such cases, it is recommended to assess low-fidelity models or alternatives to accelerate simulations, focusing mainly on the most impactful phenomena related to WAG-CO2 injection.
Carbon Capture on FPSOs
Authors: Touzé L. Le , Fourrier F. , Berendsen R. , Yamamoto S. , Kamijo T. , Tanaka Y.
Published: April 2024

The paper presents the development of a flue gas carbon capture solution for gas turbines on FPSOs, which is the main source of GHG emissions onboard FPSOs. It addresses the design aspects, including layout and performance, together with the execution challenges, such as construction and commissioning.

Based on the technical challenges raised by low CO2 concentration gas flow treatment offshore, the overall approach has been to combine the skills and experiences of an FPSO company and a technology provider specialist. The starting point has been to evaluate the global demand in terms of power generation required onboard an FPSO, then assess the most suitable technology available with the required level of maturity to meet short-term market needs. The carbon capture plant has then been sized based on a specific gas flow associated with the power demand. A moving column study was then performed to prove the overall performance of the plant. This study provided reliable tower sizing. Tower sizing has an essential role in the carbon capture plant's performance as well as a major impact on the layout.

The main outcome of the development is that capturing CO2 from gas turbine flue gas is technically feasible offshore. The challenges are numerous; and the key challenge is the plant footprint, which has a direct consequence of the volume and characteristics of flue gas to treat. The feasibility study also showed that transposing onshore-based CO2 abatement technologies offshore is feasible. In addition, being offshore can also bring some advantages, like access to large volumes of cold water and, in some specific cases, access to CO2 reinjection capabilities. The constraints of having very large equipment on a limited area will probably drive the design by adjusting the capacity of the plant; this is a way of approaching the size of a plant that is not common in the onshore petrochemical industry. Finally, construction and commissioning will strongly influence the execution model due to the size of the plant and the utility requirements.

In summary, the study demonstrates the technical feasibility of significantly reducing CO2 emissions from FPSO operations offshore.
Accelerating the Commercialization of Marine Renewable Energy Through Parallel Deployments of Multiple Hydrokinetic Power Systems
Authors: Cahill B. G. , Davies S. E. , Johnson N. E. , Kist S. , Zarate L. , Leung P.
Published: April 2024

The objective of this paper is to outline how the technical validation and market uptake of marine hydrokinetic devices are being accelerated through the demonstration of the technology across multiple operating environments and use cases. This paper will describe how a single cross-flow hydrokinetic turbine design has been incorporated into a range of power systems covering multiple market applications across river and tidal operating environments. The technology has been advanced through a design and testing pathway that has spanned seventeen system deployments and has culminated in the parallel operation of six devices across four locations in the US and Canada in 2023. The paper will demonstrate how these projects have been delivered, combining internal engineering, development, and operational expertise with partnerships with communities, research organizations, regulators, and suppliers.

The paper outlines the lessons learned from the installation and operation of ongoing hydrokinetic turbine deployments at four distinct river and tidal environments across North America. It will demonstrate how the performance and survivability of the core technology are being validated across a wide range of challenging conditions, and how operations and maintenance capabilities must be scaled up to manage parallel projects safely and effectively. Furthermore, the data and operating experience generated through these installations are helping to develop the business case for the commercial application of these power systems in providing baseload renewable power to remote and island communities as well as in industrial-scale use cases. Finally, the paper will share how these projects are helping to accelerate the growth of the installed hydrokinetic device capacity in 2024 and beyond by opening up new project opportunities of greater scale and commercial impact across global markets, including demonstrations on the Mississippi River, in South America, and Europe.