bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Thin Membrane to Reduce Weight and Footprint of Offshore Sulfate Removal Units
Authors: Hepp Rodrigo , Huang Xiaofei , Banham John , Franks Rich 
Published: April 2023

Abstract
In the past three years, several offshore platforms have commissioned sulfate removal units (SRUs) with a new, Thin-Membrane Technology which allows the highest active membrane area to be packaged into the standard spiral wound, sulfate removal element. These newly installed elements are the first of their kind to utilize the new technology and demonstrate how offshore platforms can benefit from this innovation.
The spiral wound element was developed in the 1970s to package RO and NF membranes into a compact, efficient, and modular spiral element. Since that time, incremental improvements in element design and materials of construction have led to enhanced efficiencies and productivity. However, the overall element design and membrane construction have remained largely unchanged. Most notably, in recent years, efforts to fit more material into the present spiral element configuration reached an optimal plateau. Advances in automated manufacturing resulted in either increasing the membrane surface area or increasing the thickness of the feed/brine spacer. Either enhancement could be selected depending on the quality of the feedwater or the efficiency of the pre-treatment. However, it was not possible for the designers of SRUs to capitalize on the benefits associated with both enhancements simultaneously. For this reason, when treating high quality feedwater, SRU designers prefer to use spiral elements that contain higher surface area to reduce capital cost, footprint, and weight. When treating high fouling feedwater with minimal pretreatment, SRU designers use elements with the thicker feed/brine spacer to reduce differential pressure losses, minimize fouling and improve cleaning effectiveness. Designers selecting elements with thicker spacer forfeit the benefits associated with higher area elements while designers who select elements with higher area forfeit the benefits of the thicker spacer. But in recent years, thanks to innovations in material science, a new generation of sulfate removal elements are now being manufactured and deployed in full scale systems on offshore platforms. These new elements offer both a larger surface area and a thicker feed/brine spacer.
This paper will detail the innovation in the construction of the new membrane material and compare its effects on element performance with the previous generation membranes. The paper will analyze the operation of these new elements in SRUs running on offshore platforms for as much as one year. Based on the operation of these new elements, the footprint, weight, and capital cost benefits of the new membrane relative to current membranes will be analyzed.
Seismic Stability Assessment of a Mudmat on Liquefiable Seabed
Authors: Carlton Brian , Suroor Hadi , Nadim Farrokh 
Published: April 2023

Abstract
A mudmat supporting a pipeline end termination (PLET) sits on top of a silty sand deposit that could potentially liquefy during earthquake shaking. A conventional code-based bearing capacity analysis of the mudmat was initially performed that accounted for the effect of excess pore pressures generated during earthquake shaking on the shear strength of the sand. The excess pore pressures used in the code-based approach were estimated from one-dimensional free-field site response analyses. The conventional bearing capacity analysis predicted the mudmat would be unable to withstand the seismic design loads. As a result, two-dimensional (2D) non-linear seismic site response analyses (SRA) in a finite element program were performed using an advanced constitutive model. Excess pore pressures generated during the design earthquake for the free field case (i.e. no structure), and for the near-field case (with mudmat) were estimated. Then, a bearing capacity analysis was performed in the same finite element program using the generated excess pore pressure stress field for the near-field case. The 2D SRA results showed that liquefaction (excess pore pressure ratio equal or greater than 0.9) would only occur near the soil surface due to the low effective stresses. In general, the maximum excess pore pressure ratios (ru) were between 0.3 and 0.5 for the free-field case. The addition of the mudmat decreased the ru due to the added weight of the mudmat, which increased the effective stresses. In addition, the horizontal loading on the mudmat induces initial static shear stresses in the soil, which further decreases ru for the modelled relative density of the silty sand. The bearing capacity analyses predicted that the mudmat can tolerate considerably larger loads compared to the design loads during and following the design earthquake event. The case history presented in this paper provides an advanced design methodology for evaluating mudmat bearing capacity subjected to earthquake shaking on potentially liquefiable soil. In addition, it shows the benefit of performing advanced analyses with site-specific data, which reduces uncertainty and can provide increased reliability and significant cost savings to the overall project.
Achieving Zero Flaring in Offshore Gas Fields
Authors: Alsuhali Zaid , Alsharif Ahmed , Nengkoda Ardian 
Published: April 2023

Abstract
The facilities associated with producing nonassociated gas from offshore fields consist of wellheads and tie-in platforms, which are equipped with flare systems. At wellhead platforms, the flares are maintained where a high integrity protection system (HIPS) is provided at each wellhead for over pressure protection. In addition, continuous flares are usually provided at tie-in platforms as another layer of protection. The initiative is to convert tie-in flares to maintenance, which will eliminate continuous flaring and further minimize the emissions. There are three protection layers consisting of Emergency Shutdown system (ESD) system, a HIPS system, and mechanical relief valves with partial flaring at the tie-in platforms, which activate in case both ESD and HIPS protection systems at the wellhead platform do not respond to an overpressure condition. Normally the original design will have the relief system and continuous flaring at the TPs manifolds as another protection layer. However, the HIPS design stated that the design shall ensure that HIPS alone bridges the safety risk gap. A methodology and comprehensive engineering assessment was conducted to evaluate the risk for modification of continuous flare to maintenance flare considered with partial flare and without partial flare. The study concluded that continuous flaring is no longer required and the HIPS alone is sufficient for over-pressure protection. This initiative will eliminate thousands of tons of CO2 emitted to the environment from the continuous flaring. The total cost savings analysis includes gas value creation and maintenance cost savings such as propane (fuel) burning reduction, flare tip replacements, and maintenance costs.
Vito Project: Subsea System Goes Back to Basics
Authors: Thurston Kevin W , Ramanathan Karthik 
Published: April 2023

AbstractIn 2009, the Vito field was discovered in more than 4,000 ft of water approximately 150 miles offshore from New Orleans, Louisiana. The project produces from reservoirs nearly 30,000 feet below sea level. The project underwent major redesign to remain competitive, and this paper describes changes within the subsea system. This paper is part of a Vito Project series at OTC 2023, and the other papers are listed in the references.As the industry and market began to change in 2015, the project faced significant financial hurdles, and the project team decided to refresh the field development concept to reduce cost and simplify. This paper focuses on the subsea production system and some of the key decisions leading to the selected design and the approach the team used for making these decisions. It also discusses how the project execution model was established, and the modifications made during project execution to react to schedule challenges, the unprecedented impacts of COVID-19, and a tightening offshore market.
Incorporating Data Confidence and Scoring Sensitivity into Site Selection Ranking in Depleted Hydrocarbon Reservoirs
Authors: Callas Catherine , Kovscek Anthony R. , Benson Sally M. 
Published: April 2023

Abstract
Carbon capture and sequestration (CCS) is playing a role in mitigating carbon emissions, and that role is expected to grow dramatically with time. A key element to the widespread deployment of CCS is finding a suitable sequestration site for carbon storage. Site screening and ranking frameworks designed to provide insights into the suitability of storage sites are only as effective as the underlying data used. Therefore, in this work, data confidence is incorporated into a quantitative, criteria-driven methodology developed to assess the potential suitability of depleted oil and gas reservoirs for carbon storage. A sensitivity analysis was then performed on criterion weightings to explore the results’ variability. The criteria-driven workflow and data confidence analysis were applied to fields in the Gulf of Mexico and existing carbon storage projects in depleted hydrocarbon reservoirs. Including data confidence in the scoring of sites in the Gulf of Mexico decreased the technical field score by 4% to 15%, with the most significant changes stemming from heavily weighted criteria with low data confidence. As data confidence increases for a site, the site becomes more desirable even if the criteria scores do not change since more information about the site is known. Engineering solutions can be used to improve lower-scoring criteria.
Comprehensive Monitoring of Assets in Oil & Gas Plant Using Acoustics and Vibrations
Authors: Mishra Rajat , Wong Liang Jie 
Published: April 2023

Abstract
The Oil and Gas plants operate using a network of pipelines as well as mechanized machines that help in both extraction as well as transmission of the product. These assets have an important role in maintaining an overall health of the plan and thus require regular maintenance. This maintenance is often subjective and still leads to failures, resulting in downtime and thus affecting the revenue hours of a particular asset. We suggest a comprehensive solution for monitoring both the motorized assets and the pressurized pipelines in an oil and gas plant using acoustics and vibrational analysis. This solution is currently being tested for monitoring large and small diameter pipelines as well as pumps in water reclamation or desalination plants in Singapore and could be easily opted for O&G industry.
Pairing Offshore Wind with Existing Production Assets: Utilizing Generation Overcapacity to Decarbonize Compression Trains
Authors: Bowman Travis , Ventrelli Saverio 
Published: April 2023

Abstract
Combustion in gas turbines or diesel gensets typically represents one of the largest sources of carbon emissions on offshore production and drilling installations (second only to flaring). Significant potential exists to decarbonize these assets via electrification. Many regions of the world where large-scale wind developments are planned or currently being built are also centers for oil and gas production (e.g., North Sea, Gulf of Mexico, etc). It is logical to expect that in the coming years, opportunities will arise for operators to directly utilize the electricity generated by these wind farms to reduce their carbon footprint. This paper explores possibilities for supplementing conventional power generation on offshore production installations with clean electricity from offshore wind farms. It discusses the feasibility of powering large production assests in deepwater and smaller assets in shallow water.
The paper focuses primarily on curtailement utilization (i.e., taking power from the wind farm during times of overproduction) and the inherent commercial capacity of such a scenario. Additionally, it addresses steps/measures operators will potentially have to take in relation to the inherent intermittency and unpredictability of wind generation. Electrical power continuity, stability, and magnitude are crucial to production, as well as meeting required process heat requirements on the topsides. Thus, the utilization of combined cycle for deepwater large assets is also discussed.
Evaluation of a 15 MW Turret Moored Floating Offshore Wind Turbine
Authors: Liu Allen Yonghui , Su Zhiyong , Chen Jiaxing , Yu Hao , Duggal Arun , Kolb Joel Andrew 
Published: April 2023

Abstract
Floating offshore wind is one of the most promising renewable energy sources over the coming decades and development of the floating substructure is of the most critical step for success of any floating system concept. A novel single point moored Floating Offshore Wind Turbine (FOWT) concept with the IEA 15 MW reference wind turbine is designed and evaluated in this paper. The FOWT consists of a traditional three-column semi-submersible with connecting truss beams and heave plates, A-frame airfoil shaped tower supporting structure, Rotor-Nacelle-Assembly (RNA), and a disconnectable turret system for stationkeeping.
The platform is designed to weathervane freely around the turret to passively align the FOWT heading to the wind direction with yaw restoring function from a tailor-designed airfoil shaped A-frame tower. The passive alignment capability could potentially eliminate the active yaw system on top of the tower and the active ballasting system in the hull to improve the overall system reliability. The platform tilts, nacelle accelerations, tower bottom bending moment, mooring dynamics, vessel offset, self-alignment performance and efficiency of power generation under steady misalignment are investigated numerically using coupled aero-hydro-servo-elastic model in time domain for both operational and extreme conditions. Statistics of each design parameter are discussed for various design load conditions. A sensitivity study of floating tower natural frequency was also carried out and discussed in both frequency and time domain to understand its impact on the mooring system response. The yaw misalignments studies are presented for the normal operational DLC1.1 and DLC1.3 with both colinear and cross combinations of the wave, wind, and current conditions. Challenges and benefits of the single point moored FOWT concept are summarized and presented from the studies.
Real-Time Machine Learning Application for Formation Tops and Lithology Prediction
Authors: Ziadat Wael , Gamal Hany , Elkatatny Salaheldin 
Published: April 2023

Abstract
During the drilling operation, the drill string is subjected to different geological formations which have distinct lithological characteristics that greatly affect the drilling performance and may ultimately result in increased costs of the project. The lithology of a formation can vary significantly, thus it is of paramount importance to accurately detect lithology changes and formation tops while drilling. In order to do so, geologic data and logs are often utilized by experts and operators to identify lithological variations. Machine learning algorithms and random forest have been employed in recent years to improve the process of lithology prediction, enabling more accurate results at faster rates. Machine learning-based systems incorporate a wide range of indicators such as rock types, mineral composition, sedimentary structures and microfossils for efficient lithology prediction. Additionally, random forest classifiers are beneficial due to their robustness with respect to outliers as well as their ability to capture complex relationships between variables from multivariate input datasets. With this approach, an effective operational strategy can be formulated based on the identified formation lithology in order to reduce incident costs associated with unexpected wellbore issues or instability caused by lithological changes. This technique also provides valuable insight into understanding subsurface conditions for more efficient resource exploration and production operations. limitations and drawbacks of this approach as cost and lag time. The current study proposed an intelligent machine learning solution for auto-detecting drilled formation tops and lithology types while drilling in real-time utilizing drilling surface data. Machine learning techniques are technically employed for developing real-time prediction models for the formation tops and lithology type from the surface drilling data as weight on bit, drill string speed, torque, pumping pressure and rate, and drilling penetration rate. This study implemented random forest and decision trees as two machine learning classifiers to develop real-time models using a data set of composite lithology schemes of five drilled formations. The methodology approach presents a comprehensive layout for data collection, preprocessing, data statistics and analytics, feature engineering, model development, parameters optimization, and prediction performance evaluation. The results showed a high prediction performance for the models for training and testing with overall accuracy higher than 95 through detecting complex lithology schemes. Predicting the drilled formation's tops and lithology while drilling in real-time through the developed solution will provide a technical guide for optimizing the drilling parameters for better drilling performance and optimized mechanical-specific energy to have a safe operation and cost savings.
Multi-String Analysis of a Mudline Hanger System in High Temperature Wells During Production
Authors: Sathuvalli Udaya B R. , Suryanarayana P. V. Suri , Bathgate Grant , Delgado Johan , Arcos Renato , Painter Jay , Rahman Shaikh 
Published: April 2023

Abstract
We present a semi-analytical method to analyze the multi-string mechanical response of the tubulars, the wellhead and the mudline hangers (MLH) in offshore wells with a mudline suspension system (MLS). The MLS introduces redundancies at the MLH shoulders. In our method, the tubulars are modeled as elastic springs, and the load transfer pathways at the MLH shoulders are represented by displacement constraints. The length changes caused by pressure and temperature changes during a given well operation are combined with the as-installed conditions of each casing to determine the contact force at the MLH suspension point. Though the resulting set of equations for the multi-string response is linear, the interaction of the MLS with the surface wellhead cannot be resolved a priori. Therefore, an iterative method to determine a final response that is consistent with the restrictions imposed by the MLS hardware is used. Our method is computationally simple, and can be implemented in a spreadsheet. In the past, such problems have been solved with finite element analyses.
We apply the model to an offshore well with six strings, four of which are suspended at the mudline. The hangers at the mudline are arranged such that a suspended string transfers its weight to the next outer string. Further, the MLS hardware is such that, a lifted-off string raises its immediate inner neighbor.
Forces at the surface and the mudline during production and injection are calculated. During production, the net movement at the surface, and the forces imparted to the structural members depend on the as-installed condition (including pre-load) and the annular pressures at the surface wellhead. Reduction of annular pressures significantly reduces the force on the conductor slip lock in the wellhead. Cold injection creates a net downward force at critical locations in the MLS.
The model was used to show that the net downward force did not exceed the design capacity of the MLS hardware, and to define annulus pressure management procedures to maintain well integrity.
Research and Application of Water Breakthrough Rules in Offshore Edge Water Heavy Oil Reservoirs
Authors: Chen Cunliang , Yue Baolin , Zhang Junting , Han Xiaodong , Wu Xiaohui , Wu Xuanren 
Published: April 2023

Abstract
LD Oilfield is a heavy oil reservoir with edge water, which oil viscosity is 127~544mPa·s. After 1 to 3 months of production, the water content of the oil well rose rapidly, and the oil production dropped rapidly. Therefore, it is very necessary to carry out research on the water breakthrough rules of edge-water reservoirs.
Taking the offshore LD16 oil field as the research object, relevant research has been carried out using numerical simulation technology. First, a multi-layer model is established to study the change pattern of the law of water cut rise by setting different proportions of the reserves of each oil layer. Then a single-layer model was established to study the influence of factors on the water breakthrough time of oil wells, such as average permeability, grade difference, distance from edge water, water multiple, oil production speed, crude oil viscosity and other factors. And the relative range method was used to determine the main controlling factors. On this basis, the orthogonal design method is used to design the simulation plan. According to the simulation results, an empirical formula for predicting the water breakthrough time of edge water reservoirs is established using intelligent algorithms.
Research shows that the difference in reserves between layers has an impact on the law of water cut rise. The water cut of oil wells rises more slowly when water cut in the main layer breaks, and the water cut of oil wells rises faster if water cut in the non-main layer breaks. The research results can be used to judge the water break. Compared with oil well profile test data, the agreement rate is as high as 93%. Distance from edge water, oil production speed, grade difference and crude oil viscosity are the main controlling factors that affect the water breakthrough time of LD16 oilfield. Intelligent algorithms can fit formulas well. The prediction result of the empirical formula is consistent with the actual situation of the oil field. Compared with the actual situation, the error rate is only 3.5%. The research results can be used to predict the water breakthrough time of oil wells.
The research results have certain guiding significance for improving the development effect of heavy oil edge water reservoirs and will be extended to more oil fields.