bluuebunny/crossref_metadata_2025_split huggingface dataset:
Subsea Cable Applications in Offshore Oilfield Facilities
Authors: Liang Xiaodong , Stevens John , Kelly Dwayne 
Published: September 2013

Abstract
The increase in use of variable frequency drives (VFDs) in oilfield facilities, especially for some offshore platforms, often leads to a significant percent of VFDs in total load demand. The VFDs provide many advantages for facility operation, but also produce harmonic contents to electrical power systems. Subsea cables are widely used in offshore power distribution systems. There are two typical applications for subsea cables: 1) transmitting power from the power generation to loads on remote platforms (involving line-side harmonics of a VFD); 2) transmitting power from the output of a VFD to remote electrical submersible pump (ESP) systems (involving load-side harmonics of a VFD). The combination of VFDs and subsea cables in power systems could introduce harmonic resonance, which, if not properly mitigated, amplify certain harmonics and cause significant damage to the electrical equipment in the facilities.
An investigation was conducted for the two typical applications in offshore oilfield facilities considering harmonic resonance conditions. The first application involved parallel harmonic resonance and line harmonics, which will amplify harmonic currents. The second application involved harmonic resonance and load harmonics, which will amplify harmonic voltages. Computer simulation software programs were used to develop solutions using line-side and load-side harmonic filters to mitigate harmonics and attenuate resonance; these solutions were verified to be effective in case studies
From Schiehallion to QUAD 204 FPSO, Turret Mooring System Experience and Enhancements
Authors: Fromage Lionel , Fournier Jean-Robert , Drijver Pieter , McLeary Alwyn 
Published: September 2013

Abstract
The Schiehallion Floating Production Storage and Offloading (FPSO) is moored by a Turret Mooring System (TMS) located in 400m water depth in the Atlantic Frontier and submitted to very challenging environmental conditions. The Schiehallion FPSO went on stream in 1998. As part of the planned field development the QUAD 204 FPSO currently under construction will replace the producing unit in 2015. In both cases, SBM Offshore (SBMO) is the supplier of the Turret Mooring System. This paper compares the main features of Schiehallion and QUAD 204 TMS: mooring lines, connectors, weathervaning system, manifold and swivel stack arrangement. The performance of the key components over 15 years of operation is reported. The changes brought to the original design are highlighted and discussed.
Umbilical Lay in Challenging Environmental Conditions
Authors: Gueret Renaud , Lahiri Subhajit 
Published: September 2013

Abstract
Total E&P UK Ltd and partners DONG E&P (UK) Ltd are developing the Laggan & Tormore gas fields which are located in approximately 600 metres water depth in Blocks 206/1a, (P911) and 205/5a (P1159) respectively situated approximately 125km north west of the Shetland Islands on the UK Continental Shelf.
As part of this development, in summer 2012, Subsea 7 installed a 127 km long umbilical between the landfall at Shetland Islands and Laggan manifold. It consisted of a bundle arrangement, including two-way fibre optic communication, high voltage electricity supply, chemical supply and hydraulic power.
The installation was particularly challenging as it consisted of laying a low density product (127mm diameter, 10.6kg/m submerged weight) along a route with particularly high currents and a large range of water depths [20m–600m].
Consequently, large umbilical deflections were expected and a Subsea Depressor Device (SDD) was devised to aid installation and act as a ballast to weigh down the catenary and oppose current. It was made of a weight element with a bellmouth funnel opening on each side through which the umbilical ran and was suspended from a deck winch. The wire length was tuned to control the SDD height above seabed.
This paper details the equipment used for this challenging operation and the lay strategy that was devised for laying the umbilical in various water depths and current conditions.
Special attention was paid to securing the umbilical should the vessel weather a storm. A lazy S-wave configuration obtained with floats connected to the umbilical was devised for this purpose and has been described in the paper.
Integration and Assurance of Well Documents and Data – Essential Preparation for Tomorrow
Authors: Sawaryn S. J. , Pirie L. , Green I. , Scott A. , Cosgrove B. , Emslie I. 
Published: September 2013

Abstract
During the last four years over 330,000 electronic drilling, completions and interventions documents have been consolidated in a new document management system, improving both their accessibility and future worth to the expanding user base. The system’s document structure builds on earlier, engineer-led experience and has contributed to the new company-wide standard for managing these documents. At the same time, the document management project has eliminated over 180,000 duplicate or obsolete documents.
As part of the migration from the old system to the new one, common well names have been adopted to support integration activities both within the Wells function and also with the Subsurface and Operations communities. Directional surveys are key links between these communities and over the same period, an in-depth, field by field review of the company’s UK directional survey data has been conducted. This activity is now approximately 67% complete. Together, these activities are seen as essential preparations for the future and they have already helped streamline some activities in both asset acquisitions and disposals.
These tasks have taken time, but measured preparation plus a degree of pragmatism have ensured they remain manageable. Care has been taken to maintain the document folder structure so it remains familiar to users, whilst taking advantage of the superior capabilities, such as search and assurance available in the new system. The paper contains an outline of the structure, metadata and a description of the project’s goals and history, including some of the challenges commonly encountered in preparing, processing and exporting and importing data. Details of the directional survey data verification process is also provided.
This subject is of interest to many companies because of the scale of the exercise and the growing recognition in the industry of its technical and commercial importance.
Hull Inspection Techniques & Strategies
Authors: Caldwell Raymond 
Published: September 2013

Abstract
As field life extends, managing the hull integrity of a Floating Offshore Installation (FOI) has become more critical. Employing Class entails the hull undergoing a robust five yearly survey cycle to assure its integrity. Part of that cycle includes drydocking the vessel. FOIs tend not to drydock resulting in significant challenges to operators in managing the hull integrity of their floating installations. Consequently, some operators have chosen to extend the concepts of structural integrity management and are seeking to develop new techniques to support risk based inspection of the submerged hull and the internal cargo and ballast tank structure. Inspection techniques and the information obtained therefrom are key parameters in the assessment of structural integrity. But are these parameters well identified? What data is needed to assure hull integrity and how can we best obtain this data?
Corrib Low Temperature Start-up
Authors: Duijts Rainier , Nagle Paul , Smith Charles , Bourdel Sandrine , Levet Alexandre , Mahieu Camille 
Published: September 2013

Abstract
This paper presents the feasibility and concept selection study for the low temperature start-up of the Corrib Project. A number of diverse options were studied and their feasibility determined, but significant attention is given to the selected option which involved qualifying flexible flowlines to lower temperatures than previously were available, and to the second option, which involved the specification of a bespoke subsea warming spool pyramid structure.
The Corrib project has been ongoing for a number of years and is, at present, in the execution phase with first gas estimated late 2014 / early 2015. A number of changes are required for the ability to start-up the production facilities outside the previous operating envelope of -20°C, which was constrained by the flexible flowlines that connect the subsea wells to the manifold. This was required as a result of a number of developments that occurred during 2009 to 2010. The most promising, (a) the low temperature testing and qualification of a flexible flowline, and (b) a low temperature rigid warming spool, were studied and the optimum was selected in the concept selection stage. The newly qualified low temperature flexible flowlines will be installed prior to initial start-up.
Qualification testing of the end fitting design was performed based on the protocol presented in API RP 17B for low volatile content polymer pressure sheaths in order to demonstrate that the integrity of the end fitting sealing mechanism could withstand the potential temperature cycling predicted during service conditions. Mid scale flexible pipe and end fitting specimens were prepared and subjected to thermal cycling between the design temperatures, along with intermediate inspections and pressure tests to monitor for signs of failure initiation as the test progressed. The two specimens tested successfully and returned API RP 17B fully qualified low temperature results to -35°C with one specimen qualified to -45°C.
With the increased use of more rigorous standards on asset integrity and reliability and longer subsea tie-backs, requiring wider pipeline operating envelopes, it is likely that this extended flexible pipe operating envelope will be used in many more future projects.
Critical Buckling Load Assessment Of Drill Strings In Different Wellbores Using The Explicit Finite Element Method
Authors: Hajianmaleki Mehdi , Daily Jeremy S. , Ring Lev , Gandikota Raju 
Published: September 2013

Abstract
Previous theoretical formulations for sinusoidal and helical buckling of drill strings vary significantly and are mostly proposed for frictionless pipes without tool joints. Finite element analysis (FEA) methods have the ability to consider geometric details and large deflections. However, traditional FEA methods use shell or solid dimensional elements for this problem and are computationally expensive. In this paper, an explicit FEA based on beam and connector elements implemented in the Abaqus software is employed to study the buckling of drill strings in different wellbores. The wellbore geometry, stiffness, friction load, and friction induced torque are modeled using connector elements. A typical drill string in vertical, inclined, horizontal, and curved wellbores is simulated and the explicit FEA results for sinusoidal and helical buckling loads are compared to different theoretical formulations and experimental results in the literature. The effects of length, inclination angle and string effective weight due to buoyancy as well as the effect of tool joints in straight and curved wellbores is also studied and compared to present formulations and published experimental results. Overall, it is demonstrated that using explicit FEA can efficiently study drill strings buckling behavior in straight and curved wellbore conditions.
Integrated Marine and Integrity Monitoring of FPSOs in Hostile Environments - The Importance of Observed Data
Authors: Ledgard Louise , Prislin Igor , Johnson Thomas L 
Published: September 2013

Abstract
The design and operation of an FPSO in remote locations requires detailed information on the structural response of the vessel within the local environment offshore. Monitoring of critical components including the risers, hull and mooring lines simultaneously with the local environmental forcing of waves, wind and currents at the site location, provides a valuable insight into the performance and possible extension of the integrity life of the asset.
Verification of the riser and vessel design is often theoretical and actual measured observation of the response of the critical components of an FPSO in the field is less frequent. As new technology is introduced, riser design becomes more sophisticated and extension of design life is required, it becomes increasingly important to monitor an assets performance. In hostile or remote locations where information on the environmental forcing is less known, monitoring becomes critical to assist with operational decisions, forensic investigation and the evaluation of design codes.
This paper will provide a technical overview of an FPSO integrated marine monitoring system located in a hostile environment, typical of West of Shetland. The focus of this paper will be on the marine monitoring system; however an overview of the monitoring of subsea risers and moorings will be included for completeness. A discussion on the importance of monitoring the environment and the structural behaviour on a common time base for integrity management and forensic investigation of marine incidents will be presented.
VRR &lt; 1 Is Optimal for Heavy Oil Waterfloods
Authors: Vittoratos E. , West C. C. 
Published: September 2013

Abstract
Increasingly, the reservoirs remaining to be developed have lower gravity, particularly for the older offshore basins such as the North Sea. Optimal waterflood VRR management will be the key to their economic success. Current industry paradigms and regulatory mandates assume that the light oil practice of complete voidage replacement, VRR = 1, should be continued for the heavy oil reservoirs to be waterflooded. Empirical data, laboratory experiments, and mathematical simulation methods indicate, however, that for heavy oil waterfloods the optimal voidage replacement ratio (VRR) is less than one. Analysis of empirical data from an Alaskan heavy oil reservoir (18 API) show that after water breakthrough, periods of VRR &lt; 1 are important for increased recovery. Laboratory data from an Alaskan heavy oil (12 API) waterflooded in a five foot long ‘big can’ show significantly higher recoveries with VRR &lt; 1. Numerical simulations are directionally in agreement with these empirical & laboratory observations even when only using conventional concepts.
Many more recovery mechanisms are activated with VRR &lt; 1 than with VRR = 1. Some are readily understood with existing conventional concepts. Common geological depositional environments do not permit complete waterflood sweep, and ‘cul de sacs’ of unswept oil are left behind that can only be depleted with the activation of solution gas drive by VRR &lt; 1. Less conventional concepts include the chemical changes that accompany pressure declines, that result in more surface activity and increased in-situ emulsion multiphase flow, which may self-divert to increase waterflood conformance. The numerical simulation of the VRR &lt; 1 process is difficult and only a limited number of the mechanisms can be effectively modeled. Nonetheless, directional trends have been identified.
Fulmar - Increased Production From A Mature Reservoir
Authors: Franck Nathalie , Slater Julian 
Published: September 2013

Abstract
The North Sea is a mature basin that has seen rapid decline during the last decade. This paper illustrates that with the appropriate targeted investment it is possible to arrest this decline and actually increase production from mature assets. The investments have increased recovery from existing fields and coupled with production from adjacent satellite fields, field life has been significantly extended.
Using the Fulmar platform as a case study this paper describes how during 2011 and 2012 production was raised from 3,000 to 15,000 STB/D. This was achieved through a combination of improved uptime, water injection reinstatement, wellwork and bringing online subsea tie backs.
Fulmar is a large oil field located in UKCS block 30/16, and originally contained 822 MMSTB. Production started in February 1982 and reached a plateau rate of 160,000 STB/D. By 2010 the recovery factor had exceeded 65% and oil production had declined to less than 3,000 STB/D.
Operational efficiency has been improved by implementing upgrades that target historical losses. During the second half of 2012, Fulmar export set a record for the longest continuous run in the platform’s history. Water injection has been increased after a 2010/2011 campaign to reinstate four water injection wells and upgrades to the seawater lift pumps and filtration.
The new Auk North satellite field has been tied back to Fulmar using four subsea wells giving over 10,000 STB/D boost to production. The Fulmar 2011/2012 coil-tubing campaign has reinstated three production wells, with the campaign showing that Fulmar still has significant upside potential.
Following the success of the Fulmar well campaign, additional interventions are planned for 2013 to increase production. A new dedicated subsurface team is currently working up infill well targets and a wells project team is actively working to reinstate the Fulmar drilling rig. Despite its maturity Fulmar has a number of near field discoveries and exciting exploration prospects that can continue to boost production volumes into the next decade.
Methods for Community Mapping Using Integrated Biological and Side-Scan Sonar Data
Authors: Gubanova Y. , Isachenko A. , Tokarev M. , Mokievsky V. 
Published: September 2013

Abstract
Nowadays problems of ecological and geotechnical investigations are emphasized on. A lot of scientists both mapping bottom sediments and trying to reconstruct complex, multi-component seabed system, which include biological factors either. For example, geophysical data is successfully used to evaluate contrasting biological objects on the bottom, such as communities associated with seamounts and pock-marks, oyster or mussels banks.
Material for this study was procured during surveys in Kandalaksha bay, the White Sea (Arctic). During 2010 – 2012 side-scan sonar (SSS) and VHR seismic surveys, qualitative sampling, underwater photo and video were carried out at the polygon of study.
Main task of this research was community mapping. Spatial structure of benthic communities shows very high heterogeneity in the area of survey. Thus so, samples can’t be validly interpolated to the area more than 20 m in radius. Knowledge of bottom sediment structure and topography allows obtaining a higher degree of accuracy of community mapping.
Biodiversity is related to bottom sediments type. It’s mean sonar data include information about community. On the other hand, Arctica Islandica shell big (4 cm on the average) and hard enough to backscatter high-frequency acoustic signal. There are two factors which connect community structure and side scan sonar data, this correlation may be defined. Sediments mapping was done by joint interpretation of the seismic, SSS, data of sample grain size and underwater observations.
For research of underwater landscape distribution on the polygon method of mapping was used. It’s based on integrated interpretation of traditional sampling data, underwater observation, photo and video results and remote sensing methods (side scan sonar). Detailed data of underwater landscapes were produced.
The Successful Implementation of a Competency Program in a Large Global Organization: A Case Study
Authors: Leuro Jorge , Kruger Todd 
Published: September 2013

Abstract
Introducing a competency program to an organization, whether new or the latest evolution, requires a structured approach. Each approach typically divides the activities into multiple phases, which are cyclic in nature. Regardless of what the phases are called, in essence, each project lifecycle begins with a "design" phase, followed by an "implementation" phase, and then a "measure and review" phase. The program is then continually fine-tuned though a series of project lifecycles with the intention of delivering the objectives of the program.
Often, program managers overestimate the importance of the "design," underestimate the challenges of "implementation," and overlook the need to track the correct metrics during "measure and review." This reality is highly obvious in programs that demonstrate great potential that have been implemented globally, but are only accepted by a few locations or groups, making it difficult to prove the program’s value.
This paper describes an 11-year journey of introducing a business-driven competency and employee development program within a large global oilfield service company. For each of the five defined periods of evolution, this paper provides details of the approaches taken during each phase of the project lifecycles, all of which contributed to the program’s ultimate acceptance by the organization, its proven influence on superior business results, and its alignment with the latest regulatory requirements.
The purpose of the information presented is to provide practical observations and recommendations that can help assist other organizations with the pursuit to introduce similar programs. Whereas, the evidence provided in this case study directly relates to a competency program, the relevance of the lessons learned can also be applied to other human resource (HR) initiatives.
Use of Sonar Metering to Optimize Production in Liquid Loading Prone Gas Wells
Authors: Shields C. A. , Dollard M. , Sridhar S. , Dragnea G. , Illingsworth M. 
Published: September 2013

Abstract
The East Brae platform is located in UK Block 16/3a and is operated by Marathon Oil U.K. LLC. The platform has a high pressure (HP) separator 406 psig (28 barg) and a test separator operating as a low pressure (LP) production separator 217 psig (15 barg). There are currently 12 producing gas wells; varying water-gas ratios and low gas rates result in liquid loading being a major flow assurance issue. This paper discusses the use of clamp-on sonar flow meters to minimize losses associated with well testing and the subsequent benefits that were seen with respect to production optimization and well deliquification. Clamp-on sonar flow metering is a non-intrusive technology which measures the flow velocity of the fluid stream. Sonar meters have been deployed every two months to facilitate routine production well testing of all wells to meet allocation and field management requirements. Prior to sonar metering, wells capable of only flowing to the LP separator needed to be shut-in to allow individual well tests. Wells can now be individually sonar well tested without production interruption. Different methods have been adopted to optimize production and combat liquid loading. ‘Swing’ wells use the LP separator to unload liquids and thus improve their subsequent performance in the HP separator. Sonar metering determined the optimal cycle frequency for individual wells, allowing Marathon Oil to keep the LP separator full and maintain maximum rates in the HP separator. Wireless wellhead temperature sensors have been recently installed and have been correlated to sonar measured gas rates in the well bore, providing a real-time trend of liquid loading and well performance. Currently 75% of the well stock is cycled every 4 hours in order to optimize production. This intensive well management has assisted in reducing the production decline of the East Brae field.