bluuebunny/crossref_metadata_2025_split huggingface dataset:
Slickline Deployed Fibre Optic Cable Provides First Ever Production Profile For High Temperature Gas Well
Authors: Berry S. , Dirya D. , Cowie G. , Hooker A. R. , Innes R. , Gray R. 
Published: September 2023

Abstract
Distributed Fiber Optic Sensing (DFOS) allowed us to continuously gather flow profile information from a high-temperature high-rate gas well. The objective of this case study is to demonstrate that Distributed Temperature and Distributed Acoustic data, thermal inversion modelling can be used to produce a Production Flow Profile in an environment where conventional production logging was not possible.
Cerberus modelling was performed, concluding there was a risk of tool lift whereby a conventional production logging tool string is deployed during flowing states. Therefore, a 0.181" diameter fiber slickline was selected to allow a continuous measurement over the accessible perforation interval at multiple rates without the risk of tool lift. A program consisting of a memory production log, run by standard slickline cable to acquire a shut-in profile looking for potential crossflow was followed by a DFOS run to gather DAS and DTS data during shut-in and flowing rates of 30 MMSCF/Day and 60MMSCF/Day. Near real-time DTS data was analyzed to aid in the evaluation of temperature stability at each rate change, and DAS data was processed at the wellsite to enable transmission to and analysis onshore.
DFOS data was successfully acquired and processed at wellsite and transmitted to town allowing for monitoring of data quality and decision making during the intervention. A complete suite of DAS/DTS data was acquired over the perforated interval at multiple flow rates, facilitated by monitoring near real-time transient behavior which aided in decision making for rate changes. Thermal inversion modelling and DAS analysis were performed, providing evidence of crossflow during shut-in and variations of flow allocation during the differing flow rates. It was observed that surveying at lower flow rates would have provided a different flow profile compared with normal operating rates.
As a result of deploying DFOS, data could be acquired at more realistic rates. Through performing thermal inversion of the DTS data and analysis of the DAS data a more accurate flow profile was achieved. This is the first profile to be acquired in the field for use in reservoir simulation and production modelling. This will result in more accurate reservoir and well optimization. This is a layered sandstone reservoir with a two-thirds production drop since start-up in this well. Approximately 80% of production was produced from one zone and surveillance to plan remedial action was essential to maintain economic production.
Integrating North Sea Sectors for the Development of Commercially Viable Renewable and Low Carbon Hydrogen
Authors: Haase A. 
Published: September 2023

Abstract
This paper assesses the opportunity for an integrated and circular approach to developing our offshore energy sector as we embark on the energy transition. It evaluates how offshore wind, green hydrogen production and heritage oil and gas expertise can be synthesised together to benefit all sectors to support a viable green hydrogen and wind economy.
The renewable hydrogen sector has struggled to establish a sustainable commercial model so far. This paper finds there may be significant advantages to be found in taking hydrogen production offshore, solving commercial challenges for both hydrogen and offshore wind developers, while also repurposing oil and gas expertise and assets to feed the energy transition and accelerate production timelines.
Offshore engineering experience, research, and live case-studies are utilised to investigate the opportunities for this approach. It also considers the commercial viability and benefits, as well as the ultimate offtake and transportation for produced green hydrogen and electricity.
Geomechanical Analysis of Caprock Integrity and Fault Stability for Greensand CO2 Storage Project Feasibility
Authors: Younessi A. , Kårstad E. , Basu P. , Larsen M. , Burachok O. 
Published: September 2023

Abstract
A comprehensive geomechanical assessment is carried out to investigate the upper pressure limit of CO2 injection for the depleted oil Frigg Sand reservoir in Nini field, offshore Denmark. The mechanical stability of the Frigg Sand reservoir, shale caprock and key intersecting faults were investigated under the forecasted CO2 injection plan using a field-scale coupled finite element model built for the target storage reservoir. The field-scale geomechanical model is built by preparing a 3D grid which covers the entire Greensand field structure including the basement and overburden up to the seabed. The geomechanical properties and parameters are constrained using the well-centric data and propagated in 3D grid using geostatistical approach combined with surface seismic data. A finite element model is prepared and coupled with the reservoir flow dynamic model for the interested zone of the studied area. The results of the finite element model are used to investigate the integrity of the caprock and stability of the faults over the life of the field. The results of the finite element simulation shows that the calculated minimum principal stress does not change its state to tension in any part of the field. However, a reservoir pressure above the minimum principal stress magnitude in base of the caprock may increases the risk of failure in the caprock. Hence, considering the uncertainty for the lower bound of the minimum principal stress, the risk of failure in the caprock is low until the Frigg Sand reservoir pressure exceed the estimated threshold pressure. The results also show that there is no risk of shear failure in the caprock for the entire studied area. The fault stability analysis shows that no risk of fault reactivation exists in the overburden. However, some faults may reach the critical stress state in the reservoir with high injection pressures. A reactivation in the reservoir layer may extend to the overburden and increase the risk of caprock integrity failure. Overall, the most critical mode of failure is the possible tensile failure which defines the safe operational limit for the Frigg Sand reservoir. The thorough analysis using field scale finite element simulation coupled to the reservoir flow dynamic helped to capture the risk associated to the CO2 injection operation and optimize the injection plan.
Hydrogen Backbone Link Project - Connecting Scotland to the European Hydrogen Backbone
Authors: Milne C. 
Published: September 2023

Abstract
The production and use of low carbon hydrogen will play a key role in helping Europe deliver its climate objectives and reach net zero. Affordable hydrogen transport is fundamental, with an expected opportunity for the oil and gas sector to support the development of the hydrogen economy by repurposing existing infrastructure. However, hydrogen differences from natural gas or the availability of existing infrastructure is a complex changeover to be readily available by the 2030s.
Part-funded by the Scottish Government via the Energy Transition Fund, with matched funding from industry partners during Phase 1 including Kellas Midstream, Shetland Island Council, EnQuest, Shell and Crown Estates Scotland, the Hydrogen Backbone Link (HBL) project aims to connect Scotland to the European Hydrogen Backbone to create export opportunities for Green H2 and H2 technologies. This will support the development of pan-European hydrogen infrastructure and create export capabilities by repurposing and optimising existing pipelines, installing new pipelines, or utilising other options such as marine transport by ship.
A pipeline can only be studied while considering the associated infrastructures; hence the scope was broken down to 12 separate studies including blending & deblending, hydrogen storage, compression, metering and valves. Business case risk assurance and economic modelling were also developed.
Phase 1, a feasibility stage of the project, is complete and includes 12 reports which provide the following:
Options for export methods. Options for existing or new pipelines. Findings and next steps for associated infrastructure and systems.
The studies proposed that a new pipeline is required directly from Shetland Voe Terminal or Flotta to Europe, using Emden in Germany as a study case. The new pipelines offer many advantages including operational independence, and a competitive business model of 6 % IRR with a tariff of £0.32/kg (Wood Mackenzie 2022).
With recommendations provided from Phase 1, Phase 2 is now ready to start and will include further engineering, physical testing and lab work, such as large-scale hydrogen specific metering tests. The Hydrogen Backbone Link Project continues with the goal of connecting Scotland to Europe by 2030s, within the overall target of achieving net zero.
Estimating Dynamical Mineral Dissolution for Co2 Injection Into Saline Aquifers Utilizing Deep Learning in the Ahuroa Saline Aquifer
Authors: Katterbauer Klemens , Al Shehri Abdallah , Qasim Abdulaziz , Yousef Ali 
Published: September 2023

Abstract
The geological carbon storage (GCS) in subsurface environments, such as deep permeable saline formations, is one of the achievable methods for carbon dioxide storage. There are several commercial projects such as the Sleipner field in Norway, and in Salah in Algeria have demonstrated that carbon dioxide can be safely stored in these reservoirs. The natural environments are capable to store CO2 on geologic time scales, that is mostly caused by solubility trapping. While the geological, physical and chemical conditions for the escape of CO2 are still in the research phase and how CO2 can be efficiently stored, there are several important features that represent prerequisites for the efficient storage (Xu, et al. 2017).
A core prerequisite is the availability of sufficient porosity in order to accommodate the desired volumes of carbon dioxide, and the presence of a continuous cap rock that is impermeable to CO2. Deep saline reservoirs are attractive candidates for the geological storage and based on the deep geologic storage temperature and pressure, the CO2 is typically in a supercritical but stable state. The challenge is that the introduction of CO2 into the reservoir may lead to a geochemical process which acidifies the brine via CO2 dissolution. Furthermore, the mineral surfaces are dehydrated by the dispersing CO2 phase. Experimental and field studies indicate that the geochemical reactions caused by the injection of CO2 may vary significantly between different rock types and brine compositions (Michael, et al. 2010). The low permeability of the cap rock, such as shale, have demonstrated to be reactive for higher temperature ranges, which poses additional challenges for the CO2 storage process. The dissolution and re-precipitation of carbonate minerals, and the dissolution of feldspars are generally observed for these CO2 storage reservoir sites that additionally encounter challenges related to the precipitation of clay minerals. This implies that the dissolution and secondary mineral precipitation caused by the injection of CO2 have a major impact on the porosity and permeability of the reservoir environment as well as impact the cap rock integrity (Jiang, et al. 2014).
Drilling Solutions for Offshore Wind Foundations and Export Cable Landfalls
Authors: Peters M. 
Published: September 2023

Abstract
The development of renewable energies is the focus for future energy supply. Large offshore wind farms are to be constructed and connected to a high-capacity trans-mission grid. Due to the public environmental awareness, smart installation methods are required for fast and safe construction of offshore foundations and the eco-friendly landfall installation for the export cables, with minimal impact on surroundings.
The installation of offshore foundations requires drilled installation methods, espe-cially in non-drivable soil conditions and medium to higher water depths. In addition to limitations in certain ground conditions, conventional pile-driving is reaching its limits with increasing turbine sizes. Furthermore, pile-driving has a deep environ-mental impact. Noise emissions can either require complex and expensive noise mitigation systems or cause lasting damage to flora and fauna. In the past, offshore drilling rigs have only been a non- performance driven backup option for pile-driving installations. Today, the Offshore Foundation Drilling technology provides a com- pletely drilled installation of offshore foundations, e.g. for monopile structures, pin-piles or floating anchor piles. High drilling performances can be achieved, that were previously only known in the horizontal drilling industry. Lower forces on the foun-dation pile during installation allow a more economical static pile design. Acoustic emissions can be largely avoided which finally can also lead to longer and more flexible time frames for construction. In 2022, the first equipment worldwide has been used as a standard installation method for XXL monopiles for the St. Nazaire wind farm in France, installing a total of 73 monopiles by drilling and grouting with a drilling diameter of 7,700 mm, in wa-ter depths of 15 to 25 m in rocky seabed.
The landfall sections of export cables coming from offshore wind farms are usually located in sensitive coastal areas where the operation of heavy construction equip-ment is not possible due to environmental protection requirements. Also, when dyke structures have to be crossed, this sets further increased demands on the safety as-pects of respective trenchless installation methods. Even if HDD presents a common technology for the installation of casings for subsequent pull-in of the export cables, the alternatives with remote- controlled microtunnelling systems such as Pipe Jacking or Direct Pipe need to be carefully investigated. In any case, the drilling works can be carried out from onshore to offshore to reduce marine construction costs, whereas the protective pipe can be inserted from the seaward side in a second step. This paper will give an overview of the drilled approach for offshore founda-tions and the application range of trenchless methods for export cable landfalls.
Deep Insight into Electrical Submersible Pump Maintenance: A Predictive Approach with Deep Learning
Authors: Abdalla Ramez , Nikolaev Denis , Gönzi David , Manasipov Roman , Schweiger Andreas , Stundner Michael 
Published: September 2023

Abstract
Artificial lift systems play a crucial role in the oil and gas industry by maintaining or enhancing production rates through the conversion of kinetic energy into hydraulic pressure. However, identifying abnormal performance and preventing failures remains a major challenge. Failures occur when key parameters deviate from safe operating conditions, leading to downtime and loss of production volumes. To address this challenge, the objective is to establish repeatable frameworks for constructing predictive models through the utilization of deep learning algorithms. These models provide support for engineering and operational teams through a connected alarm system that sends prescriptive notifications, enabling prompt and informed decision-making.
We approach the problem of predictive maintenance for electrical submersible pumps using a multi-task classification method. The different types of faults that can occur in these pumps are treated as individual tasks, and each task is represented by different severity grades to be predicted. To handle this multi-task classification problem, a unique model is trained end-to-end by defining a multi-task loss function. We have evaluated two different architectures for feature extraction, including a 1D CNN and an LSTM with an attention mechanism. The 1D CNN architecture consists of two convolutional and max pool layers, along with batch normalization to facilitate training. The LSTM architecture with attention was found to perform better than the vanilla LSTM in this multi-task classification problem.
This study evaluated two architectures for their performance in the predictive maintenance of electrical submersible pumps: 1D CNN and LSTM with an attention mechanism. The results showed that the LSTM with attention using lookback architecture exhibited the best performance and was the easiest to train. The 1D CNN had a comparable performance but exhibited some overfitting in the current configuration. These findings highlight the potential of using 1D CNNs for this application and the importance of attention mechanisms in LSTM models.
The maintenance of Artificial Lift Systems (ALs) requires significant resources and is traditionally performed through reactive process monitoring. An automated predictive maintenance solution using deep learning has been developed, including predictive models and a best practices guideline. This work introduces a novel automated system to reduce failures by analyzing real-time sensor data and statistical parameters to predict failures in ALs. The predictive tool supports work over plans including ESP replacement strategies, and reduces production losses.
Application of an Improved Deep-Learning Framework for Large-Scale Subsurface Flow Problems with Varying Well Controls
Authors: Huang Hu , Gong Bin , Sun Wenyue , Qin Feng , Tang Shenglai , Li Hui 
Published: September 2023

Summary
The embed-to-control (E2C) framework provides a new deep-learning-based reduced-order modeling framework for much faster subsurface flow predictions than traditional simulation. However, the previous E2C model entails a large number of model parameters, which limits its applicability to large-scale cases. In addition, the previous E2C model has not been applied to a gas-driven subsurface system or well-control optimization. In this work, we make several improvements to the previous E2C framework for more complex and larger-scale problems. First, we reduce the output dimension of the middle layers by increasing the number of downsampling layers and using the depth-wise separable (DWS) convolution techniques in the deconvolution operation. Second, we use the global average pooling (GAP) technique to reduce the model parameters. Third, we apply an “add” operation in the skip connection to fuse the features. The improved E2C surrogate model is applied to a high-dimensional gas system with flow driven by six wells operating under time-varying control specifications. In this case, we can reduce the graphics processing unit (GPU) memory usage from 19.22 GB to 2.57 GB. In the training process, a total of 160 high-fidelity simulations are performed offline, out of which 130 simulation results with partial time sequence are used for training the E2C surrogate model, which takes about 46 hours on an RTX 3090 GPU. The trained model is shown to provide accurate production forecasts under various well control scenarios during the prediction period. The online computations from our E2C model are about 6.5 seconds per case, which achieves a speedup of more than 500 factors to corresponding full-order simulations, which take about 1 hour per run. Finally, the improved E2C model, in conjunction with a particle swarm optimization (PSO) technique, is applied to optimize the injection well strategies of an oil-gas-water field case with 189 wells (i.e., 96 producers and 93 injectors). Due to the significant speedup and high accuracy of the improved surrogate model, it is shown that improved well-control strategies can be efficiently obtained.
Tribological characteristics of three-body abrasive wear on MoS2 films
Authors: CHENG Weilun , DONG Shaojiang , ZOU Song , HU Bo , LIU Qingyi 
Published: September 2023

Abstract

Aiming at the problem of the failure of bearing lubrication caused by the entry of fine dust into the spacecraft, a molecular dynamic simulation method was proposed to study the wear characteristics of the bearing lubricating film. Firstly, the atomic model of MoS2 thin film is established, and the motion state of dust particles on the surface of MoS2 thin film is divided (sliding abrasive and rotating abrasive). Secondly, the characteristics of sliding and rotating abrasive wear are studied by applying different loads to the abrasives. Finally, the surface structure of the substrate was changed to explore the adsorption and wear characteristics of the one-dimensional rough substrate. The following conclusions are obtained: 1) sliding abrasive and rotating abrasive have different wear mechanisms. The wear of sliding abrasive originates from the accumulation and release of tangential force. The main source of wear in rotating abrasive is the release of tangential force and the action of tangential force caused by rolling; 2) The relationship between sliding friction and rolling friction at the atomic scale is the same as that at the macroscopic scale. Rolling friction is much less friction than sliding friction. Rolling friction causes less damage to the film than sliding friction; 3) The one-dimensional rough substrate reduces the contact area between the film and the film, resulting in a decrease in the adsorption between the film and the substrate. The asperity structure of rough substrates reduces the lubricity of the film compared to smooth substrates.
The genome architecture of a copepod invading novel habitats
Authors: Du Zhenyong , Gelembiuk Gregory , Moss Wynne , Tritt Andrew , Lee Carol Eunmi 
Published: September 2023

Abstract

With climate change, salinity is rapidly changing in marine and freshwater habitats throughout the globe. In addition, many of the most destructive aquatic invaders are crossing salinity boundaries. Populations of the copepod Eurytemora affinis species complex are numerically dominant and highly invasive, with the exceptional capacity to rapidly invade and adapt to novel salinities. Prior studies have found striking patterns of parallel adaptation in E. affinis complex populations, with selection acting on the same sets of ion transporter genes during independent saline to freshwater invasions. Our chromosome-level genome of Eurytemora carolleeae (Atlantic clade of the E. affinis complex) revealed a peculiar genome
architecture that might contribute to its remarkable capacity to acclimate and evolve during salinity invasions. We assembled the highest quality copepod genome to date, using high-coverage PacBio and Hi-C sequencing of an inbred line generated through 30 generations of full-sib mating. Our new genome consisted of 529.3 Mb (contig N50 = 4.2 Mb, scaffold N50 = 140.6 Mb) anchored onto four chromosomes. Of its predicted 20,262 protein-coding genes, we found an extraordinary expansion of ion transporter gene families based on a comparative analysis of 13 arthropod genomes, with many of these expansions being recent. Notably, we found extreme CpG depletion of the ion transporter gene bodies,
indicating high rates of methylation at these genes and suggesting transcriptional robustness of ion transporter gene regulation. This high-quality genome provides an invaluable resource that could help yield fundamental insights into the capacity of populations to expand their ranges into novel habitats.