bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design and Performance of a TLP Type Floating Support Structure for a 6MW Offshore Wind Turbine
Authors: Guillaume Bonnaffoux , Christian Bauduin , Christine Bertolotti , Cecile Melis , Timothee Perdrizet , Yann Poirette 
Published: April 2019

The objective of this paper is to present the design and performance of an offshore floating wind turbine support structure and associated station keeping system, for a commercial 6 MW turbine. The results reported in this paper are based on a joint desk study performed by SBM and IFPEN for the development of this new floating support structure concept.
The proposed system has been extensively analyzed thanks to time domain simulation software. Time domain models incorporate the wind turbine, the station keeping system, as well as structural components of the floating foundation. The system’s behavior has been assessed for a variety of environment conditions and turbine conditions (operating, idling, fault), resulting in an extensive design load case table. In addition to the nominal system, a number of sensitivities have been investigated to test the system response to various effects: marine growth accumulation on the floating support structure, anchor position tolerance, variations of water level.
Results produced during this study show the good performance of the proposed floating wind turbine support structure and components. The proposed arrangement is capable of sustaining 20 years of operation with environment conditions up to the 50-year return period. The motions of the floating support structure are beneficial for the turbine performance, with low inclinations and low nacelle accelerations. As a consequence of these floating support structure’s low motions, the floating offshore wind turbine production is only marginally lower than the production of the same turbine on a fixed offshore foundation in the same environment. Production can occur up to the 50-year joint environment conditions.
The work presented in this paper formed part of a design dossier independently reviewed by a certification body to obtain an ‘Approval in Principle‘ for the development of the floating support structure. The study has shown that the floater motion characteristics allow similar turbine production levels to be achieved by a turbine on a fixed offshore foundation, providing support to move of floating offshore energy production.
Accurate Frequency Division Inversion Based on Seismic-Well Fusion in Seismic Data Superposition Area
Authors: Gao Wenbo , Wang Mingchun , Chen Wenxiong , Zhou Xin , Mao Yue 
Published: April 2019

Abstract
Recently, the western part of Bohai has obtained significant commercial oil discoveries in Guantao group for the first time. The old seismic data is wide, but the bandwidth is narrow. The new data bandwidth is large, but the coverage is small. Besides, the impedance difference of sand and mudstone is small. The traditional impedance inversion can't distinguish them effectively. It's very important for the next evaluation to get seismic data that can reflect reservoir effectively.
We propose to use geophysical technology to fuse high-frequency and low frequency information of new data into old data. First, the reflection coefficient of the drilling bypass is extracted. Second combined it's high frequency information with the low frequency information of the reflection coefficient which is calculated by the drilled wells. After that, the fusion coefficient is used as the sample information to invert the frequency attributes of the old data. Finally, the high frequency, the low frequency information of frequency inversion and the intermediate frequency information of the old data are fused to obtain the broadband inversion data.
In the new and old seismic data superposition area, the frequency band characteristics of the comparison inversion data and the new data are found to be quite similar. Frequency band features are also very similar. It shows that the inversion data are true and reliable. Comparison between drilled wells and the inversion data, compared to the old seismic data, the inversion data of the Guantao formation reservoir thickness is more than 8m can be effectively reflected, and the old seismic data have seismic response when the reservoir thickness is more than 15m, and the response of some reservoirs is not obvious. The seismic resolution of the inversion data is improved effectively. To sum up, the frequency division attribute inversion based on seismic well fusion can effectively improve the bandwidth of the difference data in the rear area of seismic data, and improve the resolution of seismic data.
Self-Healing Functionality in the Protection of Off-Shore Oil and Gas Assets
Authors: Wilson Gerald O , Kasisomayajula Subramanyam V , Dayton Christopher R , Navarro Aidnel G 
Published: April 2019

Abstract
In a 2016 NACE report, the global cost of corrosion was estimated to be about US$ 2.5 trillion, which amounts to about 3.4% of global Gross Domestic Product (GDP). Industries such as oil and gas that maintain a disproportionate amount of their assets in extremely corrosive environments bear a disproportionate amount of these costs. Add to these costs the environmental and individual safety consequences of material failure due to corrosion and the case for investing in new technologies geared towards improving corrosion protection can hardly be overstated. In this paper, we report on novel additives which leverage the incorporation of microencapsulated healing agents into coating systems with a view towards lengthening their service lives and that of their underlying substrates while minimizing the opportunity cost of downtime associated with maintenance. These self-healing additives have been evaluated in a broad range of coating systems selected to provide the asset owner/operator with a range of options aimed at delivering improved readiness and cost savings across the oil and gas value chain.
Here, we provide an overview of evaluations performed in in a range of coating chemistries. For all the data reported, the efficacy of the self-healing additives was evaluated by incorporation into a coating system and comparing relative to the equivalent commercially available coating. For all the comparisons, the control and the self-healing versions of the coating were damaged by scribing followed by equilibration at room temperature for a minimum of 24 h prior to accelerated corrosion testing.
A summary of the performance improvements observed upon incorporation of the self-healing additive into coating formulations is provided in Figure 1.
Recalibration of Axial Pile Capacity Methods
Authors: Van Dijk Bas , Kaltekis Kostas 
Published: April 2019

The Lehane et al. (2017) pile load test (PLT) database (new PLT database) is one of the results of a joint industry project (JIP) to investigate the reliability of (CPT based) axial pile capacity methods for driven piles. The database contains results of high quality axial load tests of piles in sand and clay. This database was used to recalibrate five pile design methods for axial pile capacity of offshore piles. The methods considered were:
For sand:
Fugro-05 (Kolk et al., 2005)
Fugro-05 (ISO, 2016)

For clay:
Kolk and van der Velde (1996)
Centre for Civil Engineering Research and Codes (CUR, 2001)
Van Dijk and Kolk (2010)
The recalibrated methods obtain a lower coefficient of variation (COV) and a better prediction of the mean of the measured capacity of the PLTs of the new PLT database and hence they can be considered more reliable than the original methods.
Validation of Cost-Effective Design Methods Using Hydrostatic Head for High Pressure High Temperature Applications
Authors: Pathak Parth D , Katsounas Nicholas P 
Published: April 2019

Validation testing of the subsea equipment designed for HPHT applications using external pressures due to the hydrostatic head can be a challenge. This paper presents the tests performed to validate the design methods proposed in OTC-27891-MS. Use of a seawater hydrostatic head enables 15,000-psi-rated subsea equipment to higher than 15,000-psi applications without the additional costs related to developing new 20,000-psi-rated equipment. The design methods utilize the guidelines in technical report API Technical Report 17TR8 and load cases per API Technical Report 17TR12.
Three primary validation tests are presented—one to validate the pressure-containing equipment, one to validate the pressure-controlling equipment, and one to validate the equipment subjected to trapped air voids. To validate the pressure-containing equipment, a 20,000-psi valve block was pressure tested to internal pressure up to 25,000 psi, with application of 5,000-psi external pressure simulating 10,000-ft applications. The valve block was strain gauged at multiple locations including the body and the bolts. The strains predicted using the finite element analysis (FEA) methods are then compared to the strains evaluated from the tests. For the pressure-controlling equipment, a 15,000-psi valve was tested to 17,000-psi upstream pressure and 2,000-psi downstream pressure across the gate of the valve assembly, with 2,000 psi external pressure, for various operational load cases to monitor the effects on performance of the gate valve and the actuator mechanism. The final validation test was performed for stem seals of the gate valve assembly, which are exposed to trapped air voids. These are tested separately to their absolute working pressures higher than 15,000 psi per the API 6A Annex F test regime.
The tests for the pressure-containing equipment showed that the actual strains in the valve block and bolts correlated well with the FEA. For the pressure-controlling equipment, various upstream and downstream pressure combinations and functions were tested which showed that the effect is minimal on the actual performance on the gate valve and the actuator and that the pressure-controlling equipment can handle the various expected differential pressure load cases. The stem seal test increased their absolute working pressure rating. These types of tests provide good guidelines on what the typical subsea equipment manufacturers can perform to validate their equipment with similar design considerations.
The paper presents the various practical tests that can be performed to validate the verification analysis utilizing the external pressures due to seawater hydrostatic head. Validation is a necessary part of the design process and can be extremely expensive and nonfeasible for subsea equipment. This paper presents a practical approach for validating the design verification analysis for subsea equipment.
Innovative Use of the CPT to Assess the In Situ Degradation of an Offshore Overconsolidated Clay
Authors: Shonberg Avi , Harte Michael , Tucker Greg , Rattley Mike , Gibbs Paul 
Published: April 2019

Abstract
The cone penetrometer test (CPT) is used extensively for the assessment of ground conditions for offshore wind farms due to its relative speed, accuracy and continuous profiling capability. For a recent offshore wind farm project in the North Sea, the CPT equipment and CPT procedure were innovatively modified to assess the residual strength and cyclic degradation properties of a highly overconsolidated clay in situ. The CPT equipment was modified to include a second sleeve, located behind the main sleeve, to assess the in situ shear strength degradation with a fixed shear strain. The CPT test procedure was modified to include a ‘cyclic CPT’ test, or ‘CPTc’ test, whereby the CPT was cycled up and down, to assess the in situ cyclic degradation of the soil at large cyclic strain amplitudes. The in situ tests gave consistent results in line with expectations for a highly overconsolidated North Sea clay. After comparing the results of the CPTc, the dual sleeve CPT and select relevant laboratory tests, a consistent response indicates the applicability of using these innovative in situ tests to assess the degradation of the highly overconsolidated clay.
Gas Hydrate Production Testing: Design Process and Modeling Results
Authors: Moridis George Julius , Reagan Matthew Thomas , Queiruga Alejandro Francisco 
Published: April 2019

Abstract
The objective of this study is to analyze in detail a process for designing by means of numerical simulation a field test of gas production from hydrate deposits, and to discuss modeling results associated with several such planned tests. The paper discusses comprehensively the data required for a reliable estimate of gas production, and provides insights into production conditions and test well operating parameters that can adversely affect a planned test. The design process begins with the development of a reliable geologic model. It is followed by an analysis of the system stratigraphy, the identification of the hydrate-bearing zones and the associated interlayers, the definition of the initial conditions (pressure, temperature, phase distributions, and geomechanical stresses), the identification of all key media properties (flow, thermal, geomechanical), and the definition of success criteria for hydrate production tests.
The geologic model is of paramount importance because it can define the system boundaries. We explore the relative importance of lateral vs. top and bottom flow boundaries within the context of the limited time frame of a field test. Initial pressures P in hydrate accumulations are relatively predictable as they are almost invariably hydrostatic. The initial temperature T distribution is important because T is the dominant parameter controlling the hydrate behavior. Knowledge of the P and T distributions are important in determining true time-invariant P- and T-boundaries. Other important initial conditions are (a) the spatial distribution of the possible phases and (b) the geomechanical stresses in the system and its surroundings. We discuss possible sources of the necessary data through analogs even when direct measurements are unavailable. We investigate the effect of heterogeneity in various parameters, and in the choice of the coordinate system. We explore the impact of spatial discretization, an important subject that has yet to be fully investigated. Finally, we provide modeling results covering a wide range of designs for production tests in oceanic and permafrost-associated hydrate deposits that describe fluid production and the flow and geomechanical system response, as well as implications for the well design and construction.
To the authors' knowledge, this is the first paper discussing in detail the recommended process for the design of field tests of gas production from hydrates, and of the key issues that can affect not only production but also the flow and geomechanical behavior of the system during the test and the definition of the well construction requirements.
Ocean Current Statistics in the Gulf of Mexico Derived from an Ensemble Approach
Authors: Srinivasan Ashwanth , Sharma Neha , Gustafson Drew , Iskandarani Mohamed , Knio Omar , Thacker Carlisle 
Published: April 2019

AbstractOcean currents are an important consideration throughout the life cycle of the many offshore projects. These currents are complex, three dimensional, dynamic and as yet poorly characterized in a statistical sense. Numerical ocean circulation models are increasingly sophisticated and are beginning to capture the structure and variability of complex ocean current systems. The starting point for model-based characterization of currents is a long time series of model outputs obtained at high spatial and temporal resolution. There are an ever-increasing number of model products, but it is not clear how to identify suitable products for a given application. Frequently, a familiar product is chosen that may not be the best choice. Here, we present an alternative approach wherein a collection of model runs, referred to as an ensemble, is used to estimate ocean current statistics at points of interest. Unlike other ensemble methods where the ensemble is used to estimate the statistics directly, we use the ensemble to construct a surrogate ocean model or an emulator using polynomial expansions. This emulator is computationally inexpensive to run and is used to sample the model outputs for large numbers of model inputs to generate full probability distributions of the model state, which can then be used to derive statistics required for design criteria. We have used the above technique to build an emulator for a numerical circulation model of the Gulf of Mexico. We present statistics of the Loop Current derived from this approach and briefly compare it with statistics obtained from measurements and other available long time-series of model outputs. Probability distributions for a sample point in the vicinity of the Loop Current are presented. It is shown that the technique can provide robust statistics and complements existing techniques.
Novel Technology Solutions Enable Phased Field Development to Maximize Returns and Minimize Risks
Authors: Skowronek Tyler , Kalia Akshay , Kjellnes Hans Fredrik Lindøen , Serrentino Ana , Chidiac Cedric , Mercer Ted , Holyfield Simon 
Published: April 2019

Abstract
The downturn has impacted our industry in many ways, not only in terms of budget cuts and headcount reductions but also in changing the way organizations work. The downturn has enabled the creation of novel technologies and efficient development plans such as phased development and early production systems that are transforming the industry, and the increased collaboration between operators and suppliers has been unprecedented. This paper discusses recent technology developments that have and will continue to reshape the approach to phased field developments.
For many years, the concept of phased field development has focused on reducing the expense of reaching first oil while planning the development for maximum recovery and deploying technology blocks that enable future add-ons for optimal asset return on investment (ROI). Game-changing efficiency resulting from earlier engagement with customers, paired with the latest technology and tools, can maximize the potential of a phased field development.
Using real-world development data as a basis, this paper details how operators can use current technology and tools to enable efficient phased field development. The case study discusses the benefits of using integrated field development and planning solutions that provide operators and suppliers a robust cloud-based collaboration solution for planning and evaluating various field development options and associated cost and schedules estimates at the click of a button. The paper then shows the impact that technology such as all-electric solutions, boosting and compression, pipeline solutions, and modular product solutions can have on the decision-making process for upcoming projects.
Modeling Method of Point Bar Internal Lateral Accretion Interlayers of Meandering River Reservoir Based on Reservoir Numerical Simulation Dynamic Response
Authors: Ye Xiaoming , Huo Chunliang , Shi Xinlei , Chen Rongtao , Yang Dongdong , Mao Yue 
Published: April 2019

Abstract
In the process of point bar internal architecture modeling, it is common to use local grid refinement method to model lateral accretion interlayers, which are often less than 1 meter thick but have a considerable impact on fluid flow. Due to huge grid amount and grid size difference, it often causes non-converging or converging too slowly of reservoir dynamic numerical simulation algorithm, which is not beneficial to practical application.
In this study, we proposed a new method to model lateral accretion interlayers based on reservoir numerical simulation dynamic response. Firstly, modeling target area of lateral accretion interlayers is defined by history matching results analysis based on the point bar level geological model. Then, the lateral accretion interlayers of the selected target area are modeled and equivalently characterized through transmissibility multiplier data instead of geometric parameters in numerical simulation model. Lastly, the multiplier value of transmissibility multiplier data is determined based on reservoir numerical simulation dynamic response.
The method of this paper only models the lateral accretion interlayers which have influence on fluid flow, which greatly reduced research workload than modeling the lateral accretion interlayers of the entire oilfield. The fluid seepage effect impacted by lateral accretion interlayers is characterized through transmissibility multiplier data; it has overcome the shortcomings of traditional local grid refinement method, and operation efficiency is greatly improved. The method has been successfully applied to model the lateral accretion interlayers for fine remaining oil distribution prediction in Q oilfield. Compared with traditional local grid refinement method, the computation time of numerical simulation is greatly reduced. The historical fitting rate of water content of a single well is grastly improved. Based on the new method, the water flooding degree coincidence rate between model prediction results and post-drilling logging interpretation is above 90%.
In this study, we proposed a new lateral accretion interlayers modeling method to improve the numerical simulation accuracy and efficiency. It can also be used in other sedimentary facies types such as deltas for internal architecture modeling.
Development and Demonstration of Novel Cryogenic Distillation Process for Offshore Gas Platform
Authors: Kim Yoori , Yeom Seungjong , Yoon Sekwang , Kim Jin-kuk , Kwon Suhyoung , Hwang Saebom , Shariff Azmi B 
Published: April 2019

Abstract
Natural gas consists of methane and other gases, which are mostly natural gas liquid (NGL), CO2, H2S and water. NGL generally refers the stream containing C2 or heavier hydrocarbons, mostly ethane and propane [5]. The recovery of C2+ components from the sale gas can enhance cost-effectivness in natural gas processing by selling highly valuable feedstocks for petrochemical sectors.
The schematic block diagram for the cryogenic distillation process widely-used in the offshore environments, is illustrated in Figure 1. Feed gas is pre-cooled before being separated in the distillation column operated cryogenic conditions. J-T valves or turboexpanders are commonly used for the expansion of gas stream which is introduced for providing necessary cooling or cold condition required for the process, while a compander may be applied to increase energy efficiency. The turboexpander-based cryogenic distillation process has been the most widely used for extracting NGL from natural gas because of its high energy efficiency and ethane recovery performance, compared to other processes [15]. Various process configurations for turbo-expander processes have been developed for improving energy efficiency or ethane recovery or adaptability [11, 13], which includes:
Gas Subcooled Process (GSP)
Cold Residue Reflux process (CRR)
Recycle Split Vapor process (RSV)
Single Column Overhead REcycle (SCORE)
Although there are differences in the configurations, in terms of heat recovery, power recovery and interconnectivity between streams, the unit operations and their sequences required for the NGL recovery through cryogenic distillation is more or less the same.