bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Robust Static Model for Geo-Mechanical Characterisation and Drilling Optimisation in Offshore Niger Delta Basin, Nigeria
Authors: Asedegbega Jerome Edafe , Eyinla Dorcas Sekemi , Oladunjoye Michael Adeyinka , Opara Alexander Iheanyichukwu , Nwakanma Alexander 
Published: April 2023

Abstract
There exists little or no core laboratory data needed for dynamic measurements-to-static elastic moduli calibration in most of the offshore fields in Niger Delta Basin. Wells are planned or drilled with little or no geomechanics inputs. Oftentimes, this has led to wellbore instability issues, non-productive time, and abandonment. To overcome this challenge, Gassmann's fluid substitution model that connects with the rock volume's geomechanical properties is therefore presented. This approach involves draining the rocks of its initial pore fluid, so that in-situ dry rock moduli (bulk and shear) and bulk density of the porous frame are estimated. Shale anisotropy, which has effect on wellbore stability analysis especially in highly deviated and shale-rich wells is corrected for in the process. The in-situ static relationship for dynamic-to-static elastic moduli transform is provided and has proven to be optimal in mud-weight design in the offset wells. The static model was compared to existing empirical formula to prove the reliability and otherwise of the model. The results showed that pore pressure exceeded 5200 psi at depth &gt; 8000 ftss with corresponding overpressure &gt;2000 psi. Sudden pressure ramp was observed between 7400 - 7600 ftss and corresponded to the interval kicks which were recorded in the offset wells. At these depths, it was observed that the initial mud-weights window was selected without recourse to geomechanics, i.e., the in-situ stresses and static rock elastic properties interplays were ignored thus, leading to an underbalanced drilling. The ranges of the obtained static rock mechanical properties, the in-situ stresses, the resulting mud-weights, and shear failure profiles at the corresponding depths are presented as reference. The most significant part of this static model is that it has been applied to drill five nearby wells successfully for the first time in this field and can be adapted for future well planning and drilling optimisation. This rock physics approach though rigorous but novel in the sense that it can reduce uncertainties inherent in the characterisation of subsurface stresses and static elastic properties, especially in the absence of core or in-situ laboratory measurements.
Using a Multi-Phase Approach to Place Submerged Landscapes into a Cultural and Archaeological Context
Authors: Evans Amanda M. , Swanson Eric A. , Fadem Cynthia M. , Scholl Nathan C. 
Published: April 2023

AbstractThis paper details the multi-phase approach used by Atlantic Shores to place submerged landscapes identified through geophysical and geotechnical surveys in support of offshore windfarm development into appropriate cultural and archaeological contexts, resulting in more accurate interpretations of potential historical significance. Where these submerged landscapes may be adversely affected by lease development, the multi-phase approach is used to tailor mitigation strategies based on the locally-specific context.
Datacentric System for Automatic HazOp Study
Authors: C. da C. B. Diniz Filipe , Braun Felipe Eduardo , Munk Marcel , R. de Paula Eduardo Augusto , Da C. Pacheco Daniela , da C. Amaral Marcelo 
Published: April 2023

Abstract
This work aims at characterizing a system which automatically generates a list of HazOp scenarios by analyzing a set of databases which contain Process and Instrumentation Diagrams (P&IDs), its objects (equipment, piperuns, instruments, valves) and relationships between them. The scope is currently limited to process systems of FPSOs. The system can explore P&IDs through the databases that describe them, mimicking the same thinking process that human beings would execute. It divides them into nodes, and searches for possible causes of process deviations. For each cause, the system verifies which consequences could happen to P&IDs objects and, if they do happen, the system looks for detections and safeguards that could protect them, also listing interlocks. All those rules are stored as tables that objectively define the relation between causes, consequences, safeguards, carrying the engineering team experience. Based on those results, a list of recommendations is built. The result is a complete HazOp Study, including subdivided nodes, description (listing equipment, piperuns, instruments, valves, data, drawings, systems), causes, consequences, detections, safeguards, interlocks, and recommendations. Standard HazOp is very time-consuming and subject to error, as it depends on human effort and attention to details, which are not constant nor error-free. The automatic analyses are based on pre-established relationship tables of cause, consequences, and safeguards, thus more compliant to rules than the conventional HazOp. Those tables can also be customized to accommodate the operator learned experience and to allow HazOp team to add more complex scenarios. All objects from those scenarios are completely identified by tag and P&ID (typically conventional HazOp fails to be that meticulous). The interlocks related to the switches are more thoroughly searched than conventional HazOp would have (including the final element and the action). The proposed system can execute the HazOp for the entire topsides from an FPSO in about 48 hours (with no human supervision), which is a very short time when compared to requirements from a conventional HazOp. The purpose is not to completely replace standard HazOp, but to complement it. The result is standardized, fast generated, and highly detailed, contributing to higher productivity and safety.
Offshore Power Generation Floater and Gravity Based Structure with Integrated CO2 Capture
Authors: Pactat Alexandre , Mariac Laurent , Orhon Dominique , Dinant Frederic , Le-Guen Anne , Volatron Jean-Philippe , Cousin François , Pourchot Thierry 
Published: April 2023

Abstract
This paper presents two novel concepts of combined cycle power generation floater and Gravity Based Structure (GBS) with a Post Combustion CO2 Capture (PCC) system integrated in the hull structure. Decarbonizing offshore power generation based on simple cycle gas turbines and using conventional post combustion CO2 capture technology is challenging due to the high flow rate of flue gas with carbon content as low as 3.5 vol%. The use of a compact combined cycle power generation with a back pressure steam turbine optimized for offshore space and weight constraints and with the carbon capture system integrated within the hull structure of a floater or a GBS allows significant cost reduction compared to a conventional design. A conceptual level engineering study was carried out to assess the technical feasibility and the economic viability of these two concepts. The following two cases studied are each based on a centralized power generation facility able to supply up to 100 MWe (Net export) of low carbon electricity to several offshore fields and where CO2 can be stored locally underground: Centralized power generation floater with CO2 capture in a West African deep-water sectorCentralized power generation GBS with CO2 capture in a shallow water sector of the North Sea
The carbon capture system is based on a generic mono ethanol amine (MEA) solvent. Process simulations, 3D models, stability studies and structural modelling were also carried out using industry's leading software. Capital cost estimates were developed for each concept. The largest parts of this capture system (direct contact cooler, absorption and water wash columns) are directly integrated into the concrete or steel structure (shell & bulkheads) to benefit from the naval architecture requirement for hull structure partitioning (watertight compartments) which thus reduces the impact on topside weight and layout.
This novel design can substantially help to overcome the challenges due to the cost and complexity to implement CO2 capture at existing or newbuild offshore facilities which are too remote for electrification from shore or to use offshore renewable sources, in order to decarbonize a significant part of the oil & gas production.
Unlocking Bulk Hydrogen Production, Storage and Transport with Learnings from Real-Life UK Trials
Authors: Elizabeth Iliffe Molly 
Published: April 2023

Abstract
The growing hydrogen economy represents a major opportunity for energy producers - many of whom have existing skills and infrastructure which can be repurposed for this sector. However, the ability to store and transport hydrogen in large quantities is a challenge. Hydrogen as an energy carrier has a relatively low volumetric energy density. A solution for transporting hydrogen at scale between supply and demand centres is therefore needed. The UK Government commissioned ERM to design two industrial scale trials to address these considerations. Key learnings from these projects will be presented to delegates, including technical challenges and solutions, commercial drivers and optimisers, and health, safety and stakeholder considerations and approaches. The two industrial scale trial projects together cover the full value chain for liquid organic hydrogen carrier (LOHC) storage, transport and use.
LOHCs are a viable means of transporting hydrogen in large quantities and have several advantages over other carriers such as ammonia, methanol or liquid hydrogen. In particular, LOHCs can be stored at ambient pressure and temperature, enabling the repurposing of existing oil infrastructure for storage and transportation. The first industrial trial evaluates the technical and economic feasibility of storing LOHC in conventional oil storage tanks, transporting it via oil pipelines, transporting it at bulk scale using conventional marine tankers and loading/unloading at existing oil jetties using standard equipment (loading arms, valves, pumps, etc). The second industrial trial involves demonstrating a design for a novel cascade tankage system that can supply large quantities of hydrogen at high pressure for a range of applications. The system stores ‘charged’ LOHC (i.e. LOHC carrying a high quantity of hydrogen) and is designed to enable hydrogen to be released from the LOHC and the ‘depleted’ LOHC (i.e. LOHC with hydrogen removed) to be stored in a unique cascade tankage system. The released hydrogen is compressed and used to supply hydrogen applications at high pressure (300-700 bar) or, at lower levels of compression, used to directly connect to a hydrogen supply line.
Insights from these industrial scale trials will be presented to delegates. The learnings cover the entire LOHC value chain including storage, transport and use in a marine context - and there will be particular focus on the technical and economic potential to repurpose existing oil and gas infrastructure for hydrogen transport via LOHC.
The ability to store and transport hydrogen in large quantities will be key to unlocking large scale hydrogen production opportunities. By sharing insights from two industrial scale trial projects covering the whole LOHC production, storage, transport and use value chain, delegates can benefit from the latest exciting learnings on this innovative solution, through real-life current projects.
Predicting Surge Wave Instabilities in the Åsgard Field
Authors: Biberg Dag , Britt Kirkedelen May , Sassan Johansson Peter , Nordsveen Magnus , Kindsbekken Kjeldby Tor 
Published: April 2023

AbstractThe work we describe here was motivated by the sizable operational difficulties and capital expenditure associated with liquid surging or "surge wave instabilities" frequently encountered in gas condensate fields in late-life production. Predicting and managing surge wave instabilities is becoming increasingly important as the number of aging fields is growing. The observed surging for low production rates at the outlet of a 45-km gas condensate pipeline in the Åsgard Field was not captured by our dynamic multiphase flow simulator. The water content in the pipeline, as measured by a radioactive tracer, was also substantially underpredicted. To better understand these shortcomings, Equinor launched an extensive experimental campaign in their explosion proof (EX certified) test facility in Porsgrunn, Norway (PLAB), using "real" fluids designed to provide a better match with field conditions than typical model fluids: a methane-based natural gas, stabilized condensate sampled from the Troll Field (low-density, viscosity, and surface tension), and water with Monoethylene glycol (MEG) (high density and viscosity). The PLAB data provided the basis for the development of new closures for the high-definition stratified flow model. The total pressure drop, condensate, and water content for the Åsgard pipeline were well predicted with the updated multiphase flow simulator. Simulations based on a refined grid and some modifications to the simulator settings revealed rich dynamics with massive surges consisting of water/MEG only, pushing a large reservoir of condensate in front. The water/MEG surges started out relatively small close to the pipeline inlet and grew considerably in length until they reached roughly 4 km as they approached the riser base. The water/MEG surges carried all the water/MEG through the pipeline. There was no water/MEG transport between the surges. The simulation results agreed with the observations at the outlet of the pipeline, where the condensate arrived before the water and the water flow was zero between the surges.
Reliability Centered Strategy for Mooring Integrity Management
Authors: dos Santos Gabriel Yudy Matsunaga , dos Santos Christian Ramalho Gomes , Azevedo Leonardo Amaral , Trovoado Leandro Cerqueira 
Published: April 2023

Abstract
Petrobras has operated offshore production units on the Brazilian coast for over 25 years. Over time, its facilities are expected to degrade due to the variety of mechanisms of damage that the offshore environment provides. Mooring systems are among the assets that present degradation throughout the operation and understanding the integrity behavior of this system throughout its lifetime is extremely important for operational safety. Mooring lines installed in floating production units of Petrobras have a wide range of operating ages (2 to 30 years) and a diversity of mooring systems (Spread mooring semisubmersible, single point mooring FPSO and spread mooring FPSO).
To optimize integrity management, a reliability-centered strategy was developed using available field data of mooring lines installed in floating production units of Petrobras. The database created for this study covered failure data, maintenance, and operational parameters of mooring line components installed between 1992 and 2021. Life data analysis was used to evaluate how the failure probability evolved with the lifetime. Therefore, the Weibull parameters of each mooring line component were estimated. The strategy aims to improve reliability and optimize life cycle cost, reducing corrective maintenance and avoiding production loss as a result.
The results show that different mooring line components have different failure rate behaviors during their lifetime. Also, parameters such as mooring system type (single point mooring or spread mooring), the position of mooring lines (due to environmental conditions), and the presence of cathodic protection are important to predict the level of degradation of the components. Through the scenarios evaluated, it was possible to define critical systems where preventive maintenance should be done and the optimal time, to improve life cycle cost and reliability.
Efficient Survey Tools for an Improved Understanding of Deep Seabed Minerals
Authors: Bosler R. Mitchell , Rønne Simen , Furmidge David , Waeroe Alfhild , Rangua Johann , Ferguson Craig 
Published: April 2023

Abstract
The proposed paper presents a novel method of sampling potential polymetallic nodule and manganese crust extraction sites that improves the efficiency and effectiveness of the campaign when compared to traditional surveying methods.
The new method utilizes a work-class ROV to perform survey sampling and testing tasks at a relatively large number of sites per dive. The ROV platform enables the use of precision measurement devices such as high-resolution sonar, cone penetrometer test (CPT) systems and core drilling machines to take in-situ samples and measurements. An ROV mounted skid with integrated sample storage drawers allows samples to be taken from numerous sites using ROV resources and manipulators. Transiting from sample site to sample site at depth improves the efficiency of sampling campaigns especially at very deep polymetallic nodule fields up to 6000 meters deep.
Initial studies have shown that high resolution sonar scans can measure nodule abundance and size with sufficient accuracy over a much greater area in less time when compared to traditional box coring methods. Studies of nodule and manganese crust sampling campaign durations have shown that transiting from site to site with the ROV at depth reduces the total duration of a representative sampling campaign by 50% or more. Incorporation of a high accuracy CPT system onto the ROV skid enables in-situ geotechnical testing at depth that are more accurate than the traditional method of measuring sub-core samples taken from box core samples at surface laboratories. For manganese crust fields, a novel core sampling drill rig is capable of drilling core holes on sea floor slopes from 0 – 90° without the need for the ROV to land. These advantages combined with the adaptable capability of manipulator systems to collect samples and the ability to provide high-definition video footage of seafloor topology will result in significant improvements to the efficiency and quality of polymetallic nodule and manganese crust site evaluation.
The expected gains in cost and accuracy of assessing deep-sea mineral resources will accelerate the pace of material extraction projects and allow greater investment in marine mineral extraction projects due to greater confidence of project success.
Digital Transformation of MEG Hydrate Inhibitor Chemical Optimization for Offshore Sour Gas Fields With an Online Solution Utilizing Supervised Machine Learning
Authors: Makogon Taras Y , Almakhaita Ahmad M , Khuraidah Mohammed A , Ganugapenta Venkateswara R , Faqehi Reham A 
Published: April 2023

Abstract
Aramco has developed and deployed several digital Hydrate MEG and Liquids Management Solutions at the 4IR Center to support hydrate management at several offshore sour gas fields. For one of the deployments, the method allowed production of 146.77 million MSCF gas in one winter season, which would not be produced otherwise. The solutions integrate thermodynamics at gas plant operations, multiphase gas-dominated flow in production trunklines, real-time analysis and virtual measurement of liquids accumulation in the lines with good accuracy which is validated by periodic checkups and confirmed by field operations. All that is accomplished without the use of commercial flow software. The method relies on several layers of supervised machine learning, with multiple layers coupled through time. Optimization also allowed to reduce the carbon emissions.
Using LWD Borehole Image Iinterpretation for Drilling Optimization: A Brazilian Pre-Salt Case Study
Authors: Aguiar Romulo Reis , Lima Angelo Dos Santos Laura , Tocantins João Pedro , Ross Jodi , Meda Rafael , Garg Shashank 
Published: April 2023

Abstract
In Brazil, pre-salt assets account for 70% of the national oil and gas production. Even after 15 years of Brazilian pre-salt exploration and development, modelling these complex reservoirs remains a challenging and uncertain task. With such high geological uncertainty, drilling campaigns experience unplanned bottomhole-assembly (BHA) trips due to severe shock and vibration, low rate of penetration (ROP), and premature polycrystalline diamond compact (PDC) drill-bit cutting structure damage.
This paper presents a case study of the successful use of an acoustic logging-while-drilling (LWD) borehole image log for drilling optimization. The ultrasonic image was acquired at high-resolution (0.2 in.), displaying clear rock formation textural and hardness variations. These contrasts are the key for understanding and simulation of drill bit-rock interaction; therefore, using the high-resolution LWD borehole image log has the potential to optimize and reduce uncertainty in the operator's upcoming drilling campaign.
Viability of the Northwest Passage as North America's Resource Export Highway
Authors: Bond James , Oldford Dan , Moakler Ed 
Published: April 2023

Abstract
For decades the Northwest Passage (NWP) has been a formidable challenge for the shipping and maritime industries. Arctic community resupply and export of Arctic resources by ship has been seen as the viable in the summer season. Changing ice conditions and the new ability to process high volumes of data in real time has allowed the quantification of risk and determination of the required ship strengthening to a specific ice class notation for seasonal and year-round export planning.
The International Maritime Organization (IMO) has provided a methodology to assess the risk of operating a ship in a specific ice regime, as seen from the bridge, or as reported in an ice chart. An ice regime, from a navigation standpoint, is the ice that the ship will likely encounter and defines several important factors including the ice-concentration, thickness, age, state of decay, and roughness. The authors have developed methods to convert ice charts into maps using the IMO POLARIS risk assessment methodology. By processing decades of ice charts, the trends of changing ice and the variation in ship access through the NWP was determined. Focusing on critical resource development locations, routes and the ships needed for seasonal and year-round export have been developed.
This paper provides an examination of the viability of various routes through the NWP for a series of ships of different ice class using the IMO POLARIS methodology. The results are presented in terms of the most recent 5-year averaged ice condition. The 5-year averaged ice conditions are compared to a 10-year dataset to highlight and contrast past and current ice conditions. Risk maps for recent individual years are also presented to illustrate year on year variability of ice conditions. Observations are drawn from the plots to summarize the necessary ice class for year-round NWP transit, and also ship traffic for specific locations (eg. Alaska North Slope LNG shipment to Asia with a 5-month (September to January) shipping window). This paper provides the answer to "What ice class ship is needed to operate in specific locations the Arctic at different times of the year.?"