bluuebunny/crossref_metadata_2025_split huggingface dataset:
SS: Donation of Petrotechnical Data to Universities, Paper: Geohazards And Fluid Seepage Assessment On The Mad Dog Field Using Bathymetry, Ultra-high-resolution Seismic And Satellite Seepage Slick Data
Authors: Cope N.R.G. , Huuse M. 
Published: June 2014

Abstract
This paper reports an environmental assessment of the geohazards and seep phenomena of the Mad Dog field area of the Gulf of Mexico. The Mad Dog block, centered on US GOM block GC782, is located on the Sigsbee Escarpment in the Green Canyon region of the Gulf of Mexico, approximately 310 km south of New Orleans. The study area covers approximately 120 km2 and extends to water depths of 1300 m – 2170 m. The available data included a deep-tow multibeam bathymetry and ultra-high-resolution 2D seismic grid in combination with satellite seepage slick interpretations from the greater Mad Dog area. Hydrocarbon seep phenomena and SAR slick data were cross-examined to determine a relationship; however although some large slicks had been mapped by SAR in the project area, the slick density was lower than anticipated and correlation to sea-bed manifestations was not always well defined. The seabed displayed substantial relief and steep gradients across a salt- related graben structure in the northwest, associated with several potential gas-related seismic wipeout features, and scarps in the central survey area. Substantial geohazards occur in the escarpment region with slope gradients up to 28 degrees and abundant evidence for mass transport deposits. The presence of strong currents that run parallel to the base of the escarpment at up to 1 ms−1 (Bryant et al. 2000) form mega furrows. Associated erosional processes in this current could mask seep phenomena and therefore be lost during bathymetry and subsurface analysis. Eight possible seep structures were observed in the region and one coned shaped mound interpreted as a mud/asphalt volcano. When correlating the locations to SAR slick data it was hard to conclusively establish a relationship between seeps and slicks due to the unknown currents. In order to reduce the uncertainty of slick and seep correlations, sea current data at various depths throughout the water column would be needed at the time of SAR capture, and access to any seafloor cores would help ground truth interpreted seepage phenomena. A better understanding of the plumbing system can only be gained from examining deeper-penetration 3D seismic data that was unavailable for this study.
An Integrated Approach for Numerical Simulation of Earthquake Generated Tsunamis: Modeling Tsunami Generation, Propagation, Inundation and Fragility Analysis of Coastal Structures
Authors: Basu D. , Das K. , Janetzke R. , Dasgupta B. , Stamatakos J.A. , Waiting D.J. , Sewell R.T. 
Published: June 2014

AbstractThe present paper presents an integrated computational approach for earthquake generated tsunami prediction. The computational framework fully integrates the earthquake generated tsunami source, open-sea wave propagation, and wave run-up with inundation and on-shore effects. In addition, preliminary fragility analyses are presented considering the dynamic inelastic (damage) response of simple structures from both hydrostatic and hydrodynamic pressures. A simplified source model is developed based on pertinent local geologic and tectonic processes, observed seismic data, and measured seafloor and land deformations. The source model establishes estimates of the configurations of seafloor deformation that are used for the initial waveform in the tsunami simulations. Well-resolved bathymetric and topographic data are used to generate the computational grid. The FUNWAVE-TVD solver with the nonlinear Boussinesq form of the Navier-Stokes equations is used to numerically simulate tsunami wave propagation and inundation. The coastal impact from the tsunami is represented through the structure fragility curve. The developed integrated approach was used to simulate the 2011 Tohoku-Oki tsunami. The tsunami fragility curve presented in this paper predicts the failure fraction (or probability of failure) as a function of wave amplitude and accounts for the water impact velocity, wave height, and dynamic load history associated with the impacting wave.
Nanostructured metallic materials in extreme environments
Authors: Zhang X. , Yu K.Y. , Chen Y. 
Published: June 2014

AbstractSevere high pressure, high temperature downhole environment in gas and oil industry, and high dose radiation in nuclear reactors posed significant challenges for the application of metallic materials. In this paper, we will review our recent discovery of nanostructured triphase metallic materials that have extraordinary high temperature thermal stability. These nanostructured metallic materials also have high mechanical strength than their coarse grained counterparts. Metallic multilayers with immiscible layer interface also have the potential for accomplishment of high temperature thermal stability. Furthermore these immiscible multilayers have extraordinary radiation resistance. By using in situ radiation experiments inside a transmission electron microscope, we show that nanostructured multilayers have exceptional radiation tolerance with capability to remove radiation induced dislocation loops. Advanced materials are clearly necessary for their application in various extreme environments. Under this context, nanostructured metallic materials metals have emerged as promising candidates with superior damage tolerance.The rapid development of numerous energy sectors calls for the design of advanced materials. Taking gas and oil industry as an example, the continuous push towards high temperature and high pressure downhole environment put increasing challenges to sustainability of currently employed metallic materials. In parallel, next generation nuclear reactors are being and designed to provide increasing service lifetime and enhanced safety and reliability. Materials to be employed to construct these reactors needs to withhold higher temperature, much aggressive radiation dose and in many cases corrosive environment. The properties of traditional metallic materials cannot accommodate these requirements. Extensive studies are being performed to search for novel metallic materials with unprecedented advanced properties. In this paper, we will discuss strategies to enhance thermal stability and radiation tolerance of metallic materials. Two examples will be provided to illustrate the ideas.
Riserless Plug and Abandonment of Pilot Holes in Ultradeepwater
Authors: Vølstad J. , Hilliard S. , Aguilar P. , Salehpour A. , Bogaerts M. 
Published: June 2014

Abstract
Offshore East Africa is a new frontier in terms of deepwater exploration. One of the new projects in ultradeepwater offshore Tanzania was located in Block 2 with water depths ranging from 1000 to 3000 m. Seismic data had shown the potential presence of shallow gas, shallow water flow, and gas hydrates while drilling the riserless section. Lack of local oilfield infrastructure, and the lack of pump and displace (PAD) mud availability made the project challenging because the surface section was to be completed within a matter of several days.
Statoil decided to drill the Tangawizi-1 U1 pilot hole to confirm the absence of shallow hazards and avoid the need for overbalance drilling the riserless section with PAD mud. The 8 ½-in. pilot hole penetrated 600 m through the critical zone below the seabed, drilled with sea water, was then plugged back by filling the open hole with cement. The decision was made to perform the cement job through the 8 ½-in. Bottomhole assembly (BHA) containing measurement while drilling (MWD) and logging while drilling (LWD) tools.
The combination of deepwater, riserless, potential shallow hazards and pumping through a BHA with significant restrictions made successfully setting balanced plugs extremely challenging. The slurry was designed following industry standards to prevent fluid influx or destabilizing the hydrates during the setting process by the use of an optimized particle size distribution (OSPD) slurry system. In addition, to successfully be placed through the BHA and avoid plugging the nozzles, this system needed to be stable and have low rheology.
The pilot hole was successfully abandoned by setting two cement plugs. Cement returns were observed at the seabed by a remote operated vehicle (ROV) and no visual flow after placement was observed.
Paleogene Secondary Recovery Analysis
Authors: Hartley Jamie , Smedstad Eric , Widjaja Ervina , Nandakumar Maya 
Published: June 2014

Abstract
The Paleogene has been shown to contain very large reserves. The characteristics of these reserves however present some unique challenges for operators in producing them in the same economic fashion as other plays within the Gulf of Mexico. Artificial lift in the form of downhole electric submersible pumps (ESPs) or subsea mudline boosting pumps are being sought out to improve the recoverables and overall economics of Paleogene field developments.
Small improvements in recovery factor can have a significant impact on the economics given the large size of these reservoirs. Many variables come into play that can impact the overall economic performance of a field development using pumps as a means of increasing recoverables. Downhole ESPs when used in combination with mudline boosting pumps have the potential for delivering the best recovery factors, however poor reliability performance and high intervention costs associated with the use of ESPs in subsea wells can negate the value of those recovery gains. Mudline boosting pumps by comparison, have lower intervention costs, and are generally accepted as having better reliability performance over downhole ESPs.
A production performance analysis was performed for a number of configurations for ESP and mudline pumps for Greenfield developments to determine the improvement in recoverables. An economic performance evaluation was then conducted, comparing the value of the increased recoverables against costs for the hardware, the installation, annual operational costs, and intervention and maintenance costs over a 30 year field life of a Paleogene reservoir.
4D (Time Lapse) Seismic: an Emerging Tool for Underwater Monitoring?
Authors: Hubans C. , Cauquil E.C. , Brechet E. 
Published: June 2014

Abstract
The 4D approach relies upon the use of 3D seismic data acquired at different times over the same area to assess changes in temperature, geomechanical effect, pressure effect, water injection, gas injection, and natural depletion, all these effects inducing density and velocity changes. Nearly thirty years on from its first beginnings, 4D – or time-lapse – seismic monitoring has now come of age as a proven technology, and is classically applied to monitor fluid movement and differentiating between drained and undrained portions of a reservoir. It is now possible to quantitatively monitor pressure injection signals, pressure depletion (compaction) signals, and in many cases, accurately separate the effect of pressure changes and saturation changes. Such changes within the reservoir may impact the whole sedimentary column up to the seabed (i.e. the overburden section). In addition, subsea installations may impact the seabed and the very shallow geology by in situ modification of the geomechanical parameters. With proper quality control during acquisition and processing, it is expected that 4D dataset would provide significant insight regarding the evolution of the seabed and shallow sub-seabed between the exploration phase, the start-up and the production phases.
Marine Magnetic Surveying and Disturbance Field Monitoring by Autonomous Marine Vehicles
Authors: Poedjono Benny , Pai Sudhir , Maus Stefan , Manoj Chandrashekaran , Paynter Ryan 
Published: June 2014

Abstract
Directional drilling uses measurement while drilling (MWD) to infer the inclination and azimuth of the drill bit. The accuracy of the measured azimuth critically depends on the local direction and strength of the geomagnetic field. Lateral uncertainties in the bottomhole location can typically be reduced by 50% if the local geomagnetic field is known accurately. This requires both the mapping of spatial crustal anomalies as well as the continuous monitoring of "space weather" disturbance field variations during drilling operations. Traditionally, these tasks are carried out by aircraft, ships and onshore geomagnetic observatories.
A novel study employed autonomous marine vehicles for geomagnetic surveying. Two autonomous marine vehicles were equipped with towed magnetometers and were deployed for 2 months offshore the Hawaiian Islands. To investigate the accuracy of the measurements, the two vehicles surveyed exact-repeat profiles. The measurements of the two vehicles agreed to within 2nT, exceeding even the stringent 5nT standard for geomagnetic observatories. To avoid entangling the towed magnetometer, the autonomous vehicles had to be in continuous motion. They demonstrated their ability to circulate around a given target. This "base station" mode allows them to monitor the time variations of the disturbance field. After correcting for spatial gradients of the crustal field, the measured disturbance field variations were found to be in excellent agreement with the Honolulu observatory. In the final phase of the study, one of the vehicles acted as a base station, while the other surveyed a regular pattern. A total of 700 line kilometers were flawlessly surveyed by one vehicle within 14 days. The resulting crustal magnetic anomaly map agrees to within 10nT with previous, lower-quality ship-borne magnetic surveys.
This study demonstrates the utility of autonomous marine vehicles to carry out crustal magnetic surveys and monitor disturbance fields in support of offshore directional drilling operations. These new capabilities improve well placement for increased oil and gas recovery. Accurate geomagnetic reference values further enable tighter quality control of MWD equipment, enhancing safety and reducing nonproductive time.
Challenges in a Multi-Disciplinary Approach for Explosion Design of FLNG
Authors: Paris Laurent , Cahay Marc 
Published: June 2014

Floating Liquefied Natural Gas (FLNG) units have been under development for decades. They are now becoming a reality, combining the design and installation of LNG units with a traditional " FPSO". Since FLNG facilities handle large flammable gas quantities in a relatively small and congested environment compared to onshore LNG plants, the explosion risk is expected to be higher than some other offshore floating facilities. As a consequence the intensity of the resulting blast loads on the unit can be more severe even if the explosion likelihood is considered low in the design through a frequency analysis.
Even if prevention and mitigation measures are implemented to reduce the risk to ALARP (As Low As Reasonably Practicable), Safety Critical Elements (SCE), such as main equipment and structures, shall be designed to withstand the blast event. Since the explosion events are very specific (high intensity and short duration), the common design rules and tools should be updated to take into account this accidental event. In addition, the associated performance criteria for SCEs should be also modified. Finally the entire design shall comply with safety objectives (personnel protection, prevention of escalation).
This paper focuses on the philosophy of design against a blast event. It will review the critical functions of the unit that must be maintained during emergency evacuation in order to protect people and, identify the key parameters governing the explosion strength on FLNG. It will show that the derivation of effective explosion loads on structures and equipment based on computational fluid dynamics simulations is not straightforward and requires expertise both in explosion modeling and explosion response. In a second part the paper will show how all the engineering disciplines in Technip individually apply these blast loads into their design through non-linear finite element analyses. Finally, it will highlight the interface between the engineering disciplines and how a consistent demonstration through the design can be achieved in order to fulfill the safety goals, taking engineering further.
Lifetime Extension North Sea FPSO, Mooring System Replacement; Integrity and Design Challenges
Authors: Leeuwenburgh R. , Brinkhuis H.T. 
Published: June 2014

Abstract
Bluewater's Haewene Brim Floating Production Storage and Offloading (FPSO), moored by means of an internal turret mooring system in the central North Sea since 1998, ran out of its original 15 years design life. Good field performance and the tie-in of another field resulted in a targeted lifetime extension for the FPSO of 18–20 years. In the late 90s a number of turret mooring systems, with a typical design life of 15 – 20 years have been installed in the North Sea. A number of these, currently or in the near future, might also be subject to lifetime extension programs. The technical challenges experienced during the lifetime extension project of the Haewene Brim FPSO mooring system will be discussed in this paper.
The main objective for the lifetime extension program of the mooring system was twofold: to design a mooring system which allows for continuous operations for the extended lifetime and to maximize the utilization of existing components. A number of the findings, steps of the design process and challenges are described in this paper and solutions are presented. This is complemented with a discussion regarding mooring integrity issues (birdcages in spiral strand wire sections) faced with over the last few years, which made it more challenging to fulfill the original design life and to design a new mooring system within the targeted boundary conditions.
Fluid-Structure Interaction: Lowering Subsea Structure / Equipment in Splash Zone During Installation
Authors: Jia D. , Agrawal M. 
Published: June 2014

Successful installation of subsea structures and equipment is critical for offshore campaigns in development of deep-water fields. This paper presents a novel approach using Fluid-Structure Interaction (FSI) to predict wave induced motions, wave loads, dynamic stresses and deformation of subsea structure and equipment in the splash zone during installation. This approach combines transient multiphase CFD simulation including dynamic mesh motion with transient nonlinear Computational Structural Dynamics including tension forces in non-linear flexible slings. This proposed approach has been successfully implemented for lowering of a subsea manifold in splash zone during installation.
This paper has many potential applications, such as, installation of manifold, subsea tree, PLET/PLEM, suction pile, pump station, or other subsea structure and equipment.
In this coupled FSI approach, pressure loads on the structure due to wave slamming from CFD model is mapped to FEA model of structure-sling assembly, which provides motion and deformation to CFD model. The results clearly show the advantage of this FSI approach to capture the coupled physics of wave slamming and its interaction with the structure and subsequent motions of structure which is being lowered in the splash zone that other approaches cannot capture. Structural integrity of the subsea structure and equipment as well as the sling forces is well evaluated and predicted with this approach.
Traditional approaches for prediction of the motions and loads of subsea structure/equipment during installation rely on simplified formulations or empirical equations or model test to determine the wave loads on structures. It cannot simulate wave-structure interaction, nor the dynamic stress and deformation of structure/equipment due to wave-structure interaction.
The approach proposed in this paper provides a state-of-the-art FSI tool which enhances understanding wave-structure interaction in splash zone during installation. The dynamic stress obtained by using this approach can be used for quantifying fatigue damage of every component on the structure/equipment due to wave loads in splash zone during installation.
In-situ Temperature Measurement of Gas Hydrate Dissociation during the World-First Offshore Production Test
Authors: Kanno T. , Takekoshi M. , Wang X. , Chee S. , Fukuhara M. , Osawa O. , Yamamoto K. , Fujii T. , Takayama T. , Suzuki K. 
Published: June 2014

Abstract
The world-first offshore production test of gas hydrate was just performed in the deep water Nankai Trough along the Pacific coast of Japan in March, 2013. A week-long flow test successfully produced methane gas by depressurizing method from the subsea methane hydrate reservoir.
While methane gas was successfully extracted from natural hydrate, there is a strong urge for understanding the dissociation behavior and characterizing production process of hydrate through the depressurization method. This is a crucial knowledge for the future commercial production of gas hydrate.
The dissociation of methane hydrate is an endothermic reaction, and the drop of formation temperature is expected to occur as the dissociation progresses. By capturing the phenomenon of temperature decrease in-situ, the data attributed to the dissociation of methane hydrate can be obtained during production.
Two monitoring wells, uniquely designed for minimizing thermal disturbance and better thermal coupling were drilled in the vicinity of the production well, and the two types of temperature sensors using DTS (Distributed Temperature Sensing) and array-type RTD (Resistance Temperature Detector) were deployed in the monitoring wells and recorded the data not only during the flow test period but also before and after the test. DTS covered the entire wellbore interval while the array-type RTD sensors were strategically placed across the gas hydrate reservoir with higher temperature resolution and accuracy.
In both monitoring wells, the temperature decreases were observed distinctively with both sensors as the flow test progressed over a week. The data quality check confirmed both measurements were conformable to the design specification and demonstrated the strong advantages of having both sensors in this monitoring system for further interpretation to investigate the dissociation behaviors.
The framework for temperature data analysis was defined to perform thermal characterization of gas hydrate reservoir during the production test stage. The preliminary analysis on the temperature transients was performed, and the results that could explain the dissociation behaviors were obtained.