bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural Integrity Assessment of FPSO Life Extension and Relocation
Authors: Wang Xiaozhi , Sun Haihong , Lee Soontaek 
Published: June 2014

Abstract
Since the first FPSO was built in the 1970s, FPSOs have been a very popular Floating Production Installation (FPI) concept, especially in deep-water application. The mobility of ship-type FPSOs makes them easy to transit, operate in a marginal field and relocate to other fields. Self-propelled FPSOs with a disconnectable turret can sail to safe harbor during a hurricane or other emergency. Oil transportation by shuttle tankers eliminates the need for oil transportation to shore by long-distance pipeline. Because of their flexible features and mature shipbuilding experience, FPSOs are good candidates for life extension at the same field and relocation to different fields at the end of its designed life. However, most FPSOs have been in operation for an extended life, some being converted from existing tankers. A rational and reliable procedure for the assessment of FPSO structures with designated scantling to validate structural integrity after FPSO life extension and relocation is called for, taking into account the expectation of safety and economic aspects. Special consideration is to be made between life extension at the same field or same operating area with updated environmental conditions, and relocation to a new field with different environmental conditions.
Do the new broadband acquisition techniques allow us to improve subsurface geohazard detection?
Authors: Saint-André C. , Compoint A. , Cauquil E. , Pivot F. 
Published: June 2014

Abstract
Geohazards are a major threat which can affect drilling, platform anchoring, and the integrity of subsurface installations. Therefore the assessment of geohazards using geophysical data require the best achievable resolution. Geohazards need to be precisely detected, delineated and understood in order to validate geohazard free areas and safe environments for drilling and production operations. Major subsurface geohazards are gas-charged sediments, gas hydrates and over pressured sands which are generally associated to amplitude anomalies. Dutta et al. (2010) illustrated that shallow hazards detection from 3D dedicated seismic volumes (SHAZ) is perfectly valid. Saint-Andre et al. (2011) highlighted the importance during conventional seismic workflow definition, of a dedicated shallow hazards 3D processing (SHAZ cube) which can systematically be performed using adapted wokflows and would enhance spatial and temporal resolution, hence detectivity in the shallow parts. The recent developpement of broadband acquisition techniques brings out new perspectives concerning shallow hazards detection. The broader frequency spectrum of the data obtained with these new acquisition techniques may become a turning point in terms of geohazards characterization. As a result, this raises the question: Do new Broadband acquisition techniques allow to improve or replace the dedicated 3D seismic volumes for geohazards detection?
Seismic Investigation of Gas Hydrates in the Gulf of Mexico: 2013 Multicomponent and High-Resolution 2D Acquisition at GC955 and WR313
Authors: Haines Seth S. , Hart Patrick , Shedd William W. , Frye Matthew 
Published: June 2014

Abstract
The U.S. Geological Survey led a seismic acquisition expedition at Walker Ridge 313 (WR313) and Green Canyon 955 (GC955) in the Gulf of Mexico from April 18 through May 3, 2013, acquiring multicomponent and high-resolution 2D seismic data. WR313 and GC955 are established, world-class research sites where high gas hydrate saturations exist within reservoir-quality sands in a long-established petroleum province. Logging-while-drilling (LWD) data acquired in 2009 by the Gulf of Mexico Gas Hydrates Joint Industry Project provide detailed characterization at the borehole locations, and industry seismic data provide regional- and local-scale structural and stratigraphic characterization. Significant remaining questions regarding lithology and hydrate saturation between and away from the boreholes spurred new geophysical data acquisition at these sites. The goals of our 2013 surveys were to (1) achieve improved imaging and characterization at these sites and (2) refine geophysical methods for gas hydrate characterization.
In the area of WR313 we deployed 25 OBS and acquired approximately 450 km of streamer seismic data in a grid pattern with line spacing as small as 250 m and along radial lines that provide source offsets up to 10 km for the OBS. In the area of GC955 we deployed 21 ocean-bottom seismometers (OBS) and acquired approximately 400 km of high-resolution 2D streamer seismic data in a grid with line spacing as small as 50 m and along radial lines that provide source offsets up to 10 km and diverse azimuths for the OBS. These new data afford at least three times better vertical resolution of the structural and stratigraphic features of interest at the sites and enable considerably improved characterization of lithology and the gas and gas hydrate systems. Our recent survey represents a unique application of dedicated geophysical acquisition to the characterization of confirmed reservoir-quality gas hydrate accumulations. These new data and interpretations are important progress toward tapping into the vast global reserves of gas hydrate.
ESP Gas Handling Technology Increases Oil Production Over 100% in a Mature Reservoir in the Gulf of Mexico: A Case History
Authors: Cardona Andres , O'Quinn Raymond , Fry Steve 
Published: June 2014

Abstract
Current increases in the price of oil have led to a renewed exploration of unconventional reservoirs including the deep and ultra-deep waters of the Gulf of Mexico. Historically, these completions were primarily gas lift producers. Due to the depth of the reservoirs, though, there is still a significant amount of hydrocarbon that is unable to reach the surface. These reservoirs, sometimes called "brownfields, " are characterized by low/marginal production and require a comprehensive analysis to make any optimization project profitable. This analysis incorporates meticulous studies to identify candidate wells for the implementation of proven and reliable technology that will rejuvenate the hydrocarbon production. One major component of the rejuvenation is the use of new electrical submersible pump (ESP) equipment.
In the past, ESP technology has been inadequate for high gas applications; however, recent advancements in gas separators, multiphase ESP stages, shroud configurations and completion strategies have catapulted ESPs to the forefront of the pack. One example of the success of this approach can be found by examining the well in "Field-A" where ESP technologies for gas handling increased production over 200% in the wells with gas/oil ration (GOR_ in excess of 1,000 scf/BPD. This paper chronicles the approach adopted for select wells in the subject field identified as "Field-A" including: inflow and fluid analysis studies, challenges, technology selection, and production optimization results.
Deepstar 11901: Subsea Low Salinity Injection Water for Increased Oil Recovery
Authors: Anres Stephane , Delaplace Thomas , Skivington Graeme , Mateen Khalid , Kusinski Greg 
Published: June 2014

Abstract
This paper is based on work performed for Deepstar CTR11901 (for more information on the program see www.deepstar.org).
On average, only a third of in-place oil is recovered in Miocene reservoirs in the Gulf of Mexico. Water injection has been used to enhance the oil recoveries with limited success. Low salinity water injection could potentially further increase the oil recoveries achievable through seawater injection.
For deepwater oil fields and those requiring long tie-backs to the existing host processing platforms, local subsea processing systems providing low salinity water injection could be useful in improving development economics.
A Deepstar study has been carried out to evaluate the existing technologies for such subsea processing system to generate the low salinity from the seawater at 10,000 feet of water depth. Several conceptual process schemes have been defined and evaluated, employing various combinations of technologies, and compared from the point of view of operability, maintainability and technology maturity level. Technology gaps have been identified in the selected technologies and roadmaps have been defined to fill those gaps.
The paper describes the methodology that has been used to review the existing technologies for water treatment and evaluate their potential for subsea application, presents the main results of the state of the art review and gives an overview of four process schemes defined for subsea implementation of a low salinity water injection station. Whole range of technologies for water desalination have been studied including membranes, electro-dialysis and the use of hydrate formation. The defined schemes combine desalination with other function technologies in order to optimize the make-up of the low salinity water to meet the particular reservoir needs.
Developments in Computational Methods for Assessing Fatigue Life of Flexibles and Umbilicals
Authors: Dhaigude M. , Sharma P. 
Published: June 2014

Abstract
Flexible risers and dynamic umbilicals are being used increasingly in harsh environments which require reliable prediction of fatigue life. Predicting fatigue life of flexible risers and umbilicals are particularly challenging because of layered construction and helical components such as tensile armors and steel tubes. The basis for fatigue damage assessment of such elements is the long-term stress cycle distribution at critical locations on the helix elements caused by long-term environmental loading on the system. Establishment of the long-term stress cycle distribution requires global dynamic time domain analysis followed by cross-sectional analysis in a large number of irregular sea states.
An efficient fatigue analysis scheme is outlined in this paper. A detailed description is given of cross-sectional analysis techniques required for fatigue stress calculation in helix elements subjected to bending, tensile and pressure loading. Special emphasis is placed on assessment of friction stresses caused by the stick/slip behavior of helix elements in bending. These effects are considered to be of special significance for fatigue life calculations of deep water applications of flexible pipes and umbilicals due to increased contact pressure between the individual elements in the cross-section. A Joint Industry Project (JIP) with an objective of validating the stress calculation methodology by comparing with high quality bending tests has been initiated. Details of qualification testing for validating the methodology are also presented in the paper.
Interpreting the Past By Exploring the Abyss: Archaeological investigations of an early nineteenth-century shipwreck in the Gulf of Mexico
Authors: Horrell Christopher E. , Borgens Amy A. 
Published: June 2014

Abstract
Increasing deep-water oil & gas exploration, through its compliance with offshore regulatory oversight, has located significant archaeological sites in the Gulf of Mexico. These unsolved mysteries of the deep have much to tell about the unique history and culture of this region. Recently, an investigation of three early nineteenth-century shipwrecks located 170 miles off the Louisiana-Texas coast has yielded invaluable information. Following the discovery of three distinct yet unknown sonar targets during a Shell Oil seafloor hazard and archaeological survey conducted in 2011, video examination of one site, named Monterrey Wreck A, occurred in April 2012 with the National Oceanic and Atmospheric Administration (NOAA) Okeanos Explorer expedition. The tantalizing results of that expedition led to another more intensive investigation in July 2013 with a multi-team, multi-faceted mapping and artifact recovery effort. The privately funded 2013 archaeological investigation was affected through collaboration between varied federal and state partners, academic and nonprofit partners teaming archeologists, biologists, ROV specialists, and educators together in a public/private partnership to explore and learn more about this site. After detailed mapping of the wreck site, more than 60 artifacts were recovered, along with biological and sediment samples, intended to help identify and date the site and provide information about the environmental conditions occurring on a shipwreck at a depth of 4300 ft. During the 2013 investigation, the two nearby shipwrecks were also mapped and documented; confirming a hypothesis that the three shipwrecks are likely associated and perhaps lost during a single cataclysmic event such as a storm. Artifact conservation and analysis is ongoing, but preliminary research suggests that Monterrey Shipwrecks date to the early part of the nineteenth-century and are comprised of an armed vessel and possibly two consort cargo vessels or prizes. The 2013 expedition was broadcast live, via satellite, through the unique telepresence capabilities of the research vessel Ocean Explotation Trust (OET) Nautilus that enabled field archeologists and educators to describe the ongoing work and interact with the public. Continued public outreach includes report preparation and the creation of educational materials.
Assessing Uncertainty and Predictability of Regional Climate, with a Focus on Hurricanes
Authors: Holland G. J. , Done J. , Bruyère C.L. 
Published: June 2014

Abstract
The inherent uncertainty in - and predictability of - regional climate predictions over limited regions is assessed using a combination of simulations with the NCAR Nested Regional Climate Model (NRCM) and statistics. Our focus is on climate and weather extremes that have high impact on society and how these may be changing with both climate variability and change. This presentation will focus on hurricanes over the Gulf of Mexico.
An ensemble of state-of-the-art NRCM simulations is used to assess the uncertainty arising from choice of: various physical processes, initial conditions, domain sizes, boundary conditions and model breeding techniques. The objectives are to:increase our understanding of the ability of regional climate models to capture regional climate information - both at the individual and collective ensemble member levels;investigate the role of different combinations of processes in reproducing regional climate; andestimate the associated uncertainty and inherent predictability.
The study is geared towards an improved ability to select optimal combinations of model configurations to maximize the predictive signal for local climate extremes. Initial results from this assessment will be presented. In particular, we include examples specific to potential future changes in hurricane impacts on Gulf of Mexico offshore facilities.
Squall Characterization in the Gulf of Mexico
Authors: Jeans G. , Cooper C. , Yetsko C. , Bryan G. 
Published: June 2014

Abstract
This paper describes a new analysis of meteorological data that improves the understanding and characterization of winds generated by squallsin the Gulf of Mexico. The analysis begins by looking at a particularly strong squall event observed in April 2013 that created gusts that likely approached 40 m/s. Not only was the April squall extremely strong but the wind direction changed rapidly which is often very challenging to dynamically positioned vessels. Indeed one deepwater drilling rig had to make an emergency disconnect during the event. To put the April event into proper historical perspective, the paper produces preliminary estimates of squall gust probability levels based on public domain datasets. This analysis suggests that the April squall was probably close to the 100-yr event and was thus, quite rare. Perhaps more importantly, the analysis shows the 10-yr gusts from squalls exceeds the API 2MET 10-yr estimates for winter storm. This is a significant finding since the 10-yr winter storm is recommended for operating criteria in the Gulf by API recommended practices covering multiple types of offshore facilities. That said, the estimates in this paper are preliminary and further work is needed to remove uncertainty in the n-yr speeds and to quantify rapid wind direction changes before any changes to present operating criteria should be contemplated.
A Post-Installed Subsea Monitoring System for Structural and Flow Assurance Evaluation
Authors: Brower D.V. , Brower A.D. , Hedengren J.D. , Shishavan R. Asgharzadeh 
Published: June 2014

Abstract
This paper describes major advancements for deploying sensing systems on existing subsea structures as part of the Clear Gulf study. In the past, a major shortcoming of post-installed monitoring systems has been poor coupling between the sensor and structure; this study provided methods to overcome this problem. Both subsea field testing and laboratory testing were performed to verify these advancements. The Clear Gulf study is a collaboration between the offshore energy industry and NASA with the goals of risk mitigation, safety, efficiency and environmental concerns in the offshore energy industry. The study is ongoing and has investigated new methods to improve deepwater monitoring and addresses installation of advanced sensors on already-deployed risers, flowlines, trees, and other subsea assets. These highly sensitive monitoring systems will provide operators a cost-effective method for detecting and responding to potential failures, flow assurance issues, and catastrophic events.
A significant achievement was recently made in bonding methods in subsea environments. Prior to installation on Tension Leg Platforms (TLPs), subscale test articles were fabricated and tested. There was a slight decrease in bonding strength, however, the methods demonstrated adequate adhesion for structural coupling integrity on subsea components. Aging tests were conducted to ensure long-term service life potential.
Full-scale implementation was accomplished on two TLPs in West Africa. Two challenges in calibration of the post installed sensors are determining the baseline or zero state of stress and sensitivity of the fiber Bragg gratings on the clamp to actual load changes on the structure. The effectiveness of the monitoring system was enhanced by calibration methods employing fundamental predictive methods to establish both baseline and sensitivity values. The transition layer between surface and deep water levels (thermocline) required temperature compensation of the strain sensors. Vastly changing temperature profiles were measured and analyzed at this moving boundary. A method to isolate temperature effects from structural data was developed and integrated into the software algorithm. A multiplexing method was incorporated with minimum cabling and connectors to make the system redundant and fault-tolerant to inadvertent cable damage. With this unique design, severing the cable in one location leads to no loss of data.
Performance Testing of an In-Line Electrocoalescer Device with Medium and Heavy Crudes
Authors: Grave E.J. , Olson M.D. , Menchaca A.E. , Westra R.W. , Akdim M.R. 
Published: June 2014

Abstract
ExxonMobil Upstream Research Company (EMURC) recently completed a subsea technology development and qualification program which included performance testing of an in-line electrocoalescer device supplied by FMC Technologies (FMC). This paper will summarize the results from these performance tests.
Although heavy oil has been processed on-shore successfully for many decades, processing heavy oil in deepwater, subsea, or Arctic fields is extremely challenging. One key challenge is oil-water separation, in which physical separation is constrained by the high viscosity of the crude and the narrow density difference between oil and water. Installing conventional electrostatic coalescers or dehydrators is often not economical or impractical at remote locations. As part of ExxonMobil's subsea program, several different separation technologies have been investigated and tested that could enable development of these fields. One example of such a technology is FMC's InLine ElectroCoalescer (IEC).
FMC has developed an innovative, compact electrostatic technology that enhances the coalescence of water droplets dispersed in emulsified oils. This technology has the potential to considerably improve the performance of the downstream oil-water separator. By applying an electrical field to an oil-water mixture, the dispersed water droplets become polarized and reorient themselves in the electrical field. As these water droplets approach one another, attractive forces between the individual water droplets lead to coalescence. Larger water droplets are formed, that can be separated faster and more easily in the downstream separation equipment. The IEC can be used to increase the throughput, performance, and reliability of existing oil processing systems while reducing the energy consumption and/or use of chemical demulsifiers. In new processing systems, either subsea or topside, deployment of the IEC has the potential to significantly reduce the size and weight of the downstream separation equipment, thereby lowering the overall capital expenditure.
The results presented in this paper are from performance tests that have been carried out on the IEC at FMC's testing facilities in the Netherlands, under EMURC's supervision. Extensive testing was executed with both medium and heavy crude oils. The operating temperatures were varied in a range representative for subsea processing applications, where heating of the process fluids is difficult. Thus, the performance of the IEC was evaluated over a range of oil viscosities. Water-in-oil concentration, flow velocity, upstream shear, and electric field strength were also varied to investigate their effects on the IEC performance. The results demonstrate that the IEC is able to deliver high pre-conditioning performance to medium and heavy crude oil emulsions, given the appropriate process conditions and electrical settings are used.