bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Coupling of Mooring and Riser Systems and FPSO Roll motions on the Design of Flexible Risers
Authors: Rezende Flavia , Vivas Laiz , Carré Allan 
Published: April 2017

Abstract
For the development of the new frontiers in Brazil, spread moored FPSOs with a large number of flexible risers connected to one board of the unit are considered. Due to the large water depth and severe environmental conditions, the design of the flexible risers is challenging and the roll motions of the FPSO are a key parameter. The roll motions may induce large vertical displacements at the top of the risers which affect the ultimate strength of the flexible pipe as well as fatigue of end- fittings. Moreover, the vertical motions and accelerations may induce compression of the riser which could lead to exceedance of allowable curvature limit. The common practice for estimation of FPSO roll motions is to consider the unit in the free floating condition, without the presence of mooring lines and risers. The resulting motions are then imposed at the top of the risers in a decoupled way. Ideally, a fully coupled analysis should be performed in time domain in order to take into account the dynamics of the floater and lines systems simultaneously as well as the nonlinearity involved. However, as this type of analysis is very time consuming, an alternative methodology is proposed, which enables to consider the effects of coupling at early design phase at a reasonable timeframe. This methodology consists in performing preliminary numerical tests (forced motions) in order to obtain the effects of additional stiffness, added inertia and damping originated by the mooring lines and risers to be included in a decoupled motion analysis in the frequency domain. In this study we consider the example of a spread moored system in deep water depth designed for operating in Brazilian conditions. In this case it is observed that the coupling effects are very important, mainly for intermediate and shallow drafts of the unit. In particular, the lines (mooring and risers) may significantly contribute to damp the roll motions. As a consequence, the top tensions in the flexible pipes would be lowered comparing to the results of usual decoupled analysis.
Applying Risk Management Principles to the CVA Process in Offshore Wind Farm Projects
Authors: Adams Thomas G. , Byars Rain 
Published: April 2017

Abstract
The Certified Verification Agent (CVA) role has been defined by the US Bureau of Ocean Energy Management (BOEM) for offshore wind farms construction in Federal waters, and a similar CVA role has been adopted by certain states, such as Rhode Island, who have projects being constructed in state waters. The CVA plays a critical role in assuring the compliance of the offshore wind farm project with the applicable codes, standards, regulations, and plans that govern the design, construction, commissioning and operation of the project. A mature project certification process exists in Europe following the IEC standard, and there are some important differences between that and the CVA role defined by the relevant federal and state regulations in the US market. Risk management principles can help to balance the CVA effort while managing the most important risks on the project and achieving a high confidence level in overall project compliance and quality. These include techniques such as identifying critical design, manufacturing, and installation tasks, developing appropriate sampling plans for inspection, implementing comprehensive documentation review processes, and employing contingency plans for different outcomes and findings.
The Role Of Standardisation And Modularization In Reducing The Cost Of Subsea Electrical Connectors
Authors: Plant Chris 
Published: April 2017

Abstract
Wet mate electrical connectors are a key technology for the deepwater industry, and can be a significant proportion of the cost of a subsea processing project. To operate sustainably in a low value oil market, manufacturers of subsea electrical connectors must change from their current project driven, custom product approach. Cornerstones of the new approach to the current market must be standardisation and modularization.
This paper will focus on the challenges posed in designing and qualifying a connector system to meet a cross-industry specification, e.g. SEPS SP-1001 (soon to be an IEEE/IEC specification). It will focus on the difficulties in finding a common interpretation of a specification, designing in complete compliance with a cross-industry specification, and include detail of the planning and execution of on-going qualification programs, which are being run in accordance with cross-industry controls (fibre-optic and electrical) and power specifications.
We will examine the different ways in which a connector specification can be interpreted and how the interpretation drives the connector design, test arrangement design, and cost. This interpretation is particularly important when examining the cost of a qualification program and associated equipment, with costs for specialist qualification equipment contributing significantly to the cost of new product development.
Modularization is also a key enabler for cost reduction, allowing the same connector family to be used for multiple applications with only configuration, rather than project or application specific redesign. We will focus on the difficulties found when trying to identify a number of industry requirements which can be combined into a specific product, for example, subsea power distribution, long-step out, subsea compression, and direct electrical heating.
The focus on this paper will be about presenting real-world experience of design and qualification of connectors based on three case studies, for subsea power distribution, long step out electrical controls, and long step out fibre controls.
Subsea Projects Cost Reduction - Petrobras Approach, Results and Next Steps
Authors: Moreira Matoso Ribeiro Gomes F. , Dal Pont A. , Maia Arantes F. , Cavalcanti Freitas G. A. , Rodrigues Marques M. A. , Souza Salvador M. de , Santos Poli P. R. , Oliveira R. Caldeira de , Laquini S. , Santos T. Duarte Fonseca dos , Gasparetto V. 
Published: April 2017

Abstract
The Oil and Gas industry has faced an unpredictable and fast transformation in the last years. At first, there were barrel prices over U$ 100 dollars, which motivated a huge worldwide investment that pushed operators and the supply chain to respond to unprecedented growth. Due to the downturn in the oil prices, the challenge has moved towards achieving project feasibility in a low Brent scenario. The Brazilian subsea oil and gas industry has struggled with this context. Initially, with the Pre-Salt discoveries in 2006 it was necessary to develop breakthrough technological solutions to face this new frontier and to build 10 ultra deep-water production systems happen in just 10 years. Due to the recent price drop, Petrobras subsea engineering area has faced a demand to develop simpler and cost efficient solutions to reduce Pre-Salt CAPEX and OPEX.
The objective of this paper is to review how Petrobras subsea area is dealing with these challenges since the discovery of Pre-Salt in 2006 until the current downturn of the oil and gas industry. As a reaction to that, Petrobras has been running an internal strategy called Subsea Cost Reduction Plan - PRCSub. The main purpose of this program is to search for the biggest cost reduction opportunities and to promote a full integration among Petrobras subsea team and suppliers.
The PRCSub has delivered excellent results. Around US$ 500 million in savings were registered between 2014 and 2015 in the subsea scope, and between 25% of CAPEX reduction was achieved in Pre-Salt developments due to optimization initiatives for subsea design.
The paper will present a review of the initiatives, describing the technical solutions and the new business model under construction by Petrobras.
Effects of Data Resolution on Early-Stage Pipeline Route Selection
Authors: Tiffany Justin M. , Devine Christine A. 
Published: April 2017

Abstract
At times, infield and export subsea pipeline routes are manually designed and sited in the early stages of a project using only existing, publicly available, low-resolution bathymetric data with minimal consideration for the geological complexity that may affect the proposed infrastructure. Geohazards across the development area may not be identified or could be misinterpreted based on the resolution of the available data. Selecting a pipeline route before a detailed geohazard assessment is completed may result in revisions to the route, taking up valuable time and resources, and leading to significant costs.
This paper describes the workflow of an example pipeline route optimization performed on multiple datasets with varying resolutions across the same study area. Each dataset was individually analyzed and assessed for regional geohazards, then least-cost pipeline routing methods were used for pipeline route selection. We show how least-cost route optimization is affected by data resolution, geohazard identification, and geocost weighted inputs and emphasize the importance of incorporating the highest resolution data available when conducting pipeline route optimization.
Collective Summary of DeepStar® Accomplishments within Continued Service
Authors: Gomes Joseph , Kusinski Greg 
Published: April 2017

DeepStar® is an operator funded Research & Development joint industry consortium including members of the oil community such as oil & gas (O&G) companies, vendors, regulators and academic/research institutes working in multidisciplinary technology areas. The DeepStar Project has been in continuous operation since its inception in 1991, and has focused on both issues and technologies that are required to successfully tackle future development and production challenges identified by its members. These overall discussions are based on thought processes from initial equipment design, materials select and qualification, to implementing new subsea technology and continuous service or decommissioning. In recent years, DeepStar has focused improvement efforts within the area of continuous service, with a more recent focus on understanding the design for the complexity of decommissioning. This paper and corresponding presentation will highlight the successes of DeepStar's continuous service work during the conference within the Life Extension Challenges and Case Studies session. Through DeepStar, key issues have been identified and our work has progressed into the American Petroleum Institute SC2 subcommittee on offshore structures. DeepStar has recently completed three projects related to integrity management (IM) which includes risk based mooring integrity management, continuing service guidance for steel catenary risers, and ageing floating infrastructures.
This abstract outlines DeepStar's strategies, projects and accomplishments through a collaborative effort amongst operators, engineering firms, manufactories, academic intuitions, and government regulators. Through this joint effort, members have been able to minimize the cost and risk of technology development, while at the same time making the most of the organization's particular technology achievements. Deepstar's value to Participating Members has always been that it offers the opportunity to significantly leverage their technology investment. This aligns with DeepStar's vision for the development of deepwater technology, which is closely tied to the concept of cooperation and evolution of a synergistic relationship among the members within the O&G community. DeepStar has continuously confronted industry wide issues and provided a forum for discussion and technology acceleration.
Stones Development: Best in Class Risk Reduction and Cost Improvement During Project Execution
Authors: Pena Maria , Lohr Curtis 
Published: April 2017

Abstract
The Stones asset is an ultra-deepwater development located approximately 200 miles south of New Orleans in ~9500 feet of water . Final investment decision was taken in 2013, with first production achieved in September 2016. This development is part of the frontier Paleogene outboard play in the Lower Tertiary Trend that targets the Upper and Lower Wilcox formations.
In early 2014, a change management program was kicked off, originally centered on minimizing well construction risks. This change management program was organically grown, with cost and risk baselines being re-assessed bottoms up, and key opportunities identified.
Major improvements were obtained in the areas of minimization of risk and capital investment during the period of 2014 to 2016. Improved risk and cost themes centered on: (a) enhanced trade-off between subsea and well construction complexities; (b) improved subsurface imaging to increase flexibility in well trajectories; (c) deepened integration between completion choices and well designs; (d) technical functionality rationalization; and (e) supply chain improvements.
This paper highlights the key change management lessons learned that took place during the Stones project execution resulting in the project meeting the cost promise from project sanction.
Optimized Field Development Planning in the Frontier Paleogene
Authors: Varner Marc , Pena Maria 
Published: April 2017

Abstract
The Stones project is an ultra-deepwater development located ~200 miles south of New Orleans in the Walker Ridge ("WR") protraction area of the Gulf of Mexico. This development is part of the frontier Paleogene outboard play in the Lower Tertiary Trend that targets the Upper and Lower Wilcox formations.
The initial development (Phase 1) is planned for eight subsea wells directionally drilled from two drill centers with a production manifold located at each drill center. Dual 8″ flow lines will connect the two drill centers with dual 8″ risers connecting the drill centers to a Floating Production Storage and Offloading (FPSO) host. Oil is exported by shuttle tankers with gas exported through the Walker Ridge Gas Gathering System. Mudline pumps will be located at the first drill center.
The current field development plan incorporates optimizations based on information gathered during the early execution phase of the project. These optimizations were identified through multi-disciplinary integration with a focus on risk management and best-for-project decision making. This paper highlights the subsurface learnings and associated modifications to the field development plan to mitigate risk, lower costs and increase ultimate recovery.
The Stones Buoy Turret Mooring BTM: The Evolution of Design Leading to the Delivery of the Largest Buoy Ever Built
Authors: Salem A. G. , Connaulte X. S. , Webb C. 
Published: April 2017

Abstract
This paper describes the evolution of the design leading to the selection, development and delivery of Stones disconnectable Buoyant Turret Mooring (BTM) buoy. The optimization process leading to the selection and configuration of the BTM buoy is discussed, with particular focus given to the mooring- riser system payloads supported by the BTM when in the disconnected state.
A hybrid design, featuring syntactic foam buoyancy modules integrated into a steel structural skeleton, and incorporating a minimal number of steel ballast tanks, was selected over a conventional all steel buoyant hull structure. The selected design provides for a protective steel cage for the buoyancy modules, and a structural path for mooring-riser system loads into the Floating Production, Storage and Offloading (FPSO), while a large number of syntactic foam blocks are secured within the steel frame to provide adequate buoyancy to meet the in-service performance requirements. A qualitative discussion about the advantages of the selected geometry and hybrid steel-foam design is presented, including the performance characteristics of disconnection, submergence equilibrium and ballasting.
Beyond the design evolution considerations including concept selection and optimization, attention is given to manufacturing, constructability, offshore installation and operability under the latest US Gulf of Mexico (GOM) regulatory regime. The buoy's transit voyage from Singapore to the GOM for the initial offshore integration with the FPSO necessitated Transport and Installation (T&I) requirements which were embedded into the design and integration of all BTM buoy components. Buoy ballasting and de-ballasting strategy after mooring hookup and riser connection played a pivotal role in sizing critical components and equipment. In this context, the paper will explore the interrelations between design and operations in order to optimize the loading requirements.
The design decisions leading to the selection of geometries, materials and configurations of the largest and deepest offshore mooring installation are discussed. A novel solution is developed to accommodate a complex deepwater installation with a large payload mooring-riser system. Feedback on onshore fabrication and offshore integration and operations are presented.
HP/HT Sensor for Real-Time Downhole Density Measurement of Wellbore Drilling Mud
Authors: Hall J. E. , Tiliakos N. , Worst T. , Foster R. B. , Pappas J. M. , Long R. 
Published: April 2017

Abstract
There is a need to accurately measure the density of drilling mud and well flow rate at downhole locations in the wellbore. Mud density can be determined by measuring the differential pressure between two locations in the well. The most common manner of measuring flow rate is also through the use of a differential pressure sensor. The development of a true differential pressure (DP) sensor for downhole measurement at HP/HT conditions (500 Deg F and at 15,000 psi) was presented at the 2015 OTC (paper #25772-MS). The excellent performance of the initial two DP sensors led to the fabrication and testing of additional DP and absolute pressure cells to verify the design.
Since the performance of the DP sensors showed a maximum error at each of the HP/HT extremes of less than 0.02% of the upper-range limit, their use with remote diaphragms to measure the density of the drilling mud in the wellbore was considered a possibility. If successful, this measurement could be integrated into a wired drill string to not only indicate the occurrence of a ‘kick’ during drilling, but also provide unprecedented monitoring and control of unwanted changes in mud density throughout the entire length of the drill string annulus. This would provide significantly improved early warning and control of dangerous high-pressure flow into the wellbore.
Additional funding by the RPSEA 10121-4304-01 program allowed for the development of a low-differential pressure range sensor cell with a significant increase in sensitivity to a change in density of the wellbore drilling mud. Sensor performance data was obtained: (i) at ambient temperature and various common mode pressures and (ii) at ambient common mode pressure and various sensor temperatures up to 250°C.
The calibration results of the HP/HT downhole DP sensor cell with remote diaphragms indicated adequate ‘kick’ detection sensitivity to enhance drilling safety in high-pressure zones. Additionally, possible methodologies to integrate the wellbore density sensor assembly into the drill string will be discussed.
Use of Multibeam Echo Sounder MBES Backscatter and Bathymetry Data to Reveal New Insights into the Campeche Escarpment
Authors: McBee J. , Brumley K. , Mitchell G. , Gharib J. 
Published: April 2017

Abstract
The Campeche Escarpment is a prominent feature extending over 600 km along the northern flank of the Yucatan Peninsula with steep cliff faces of up to 80° and a relief of over 4000 m. Analysis of Multibeam Echo Sounder (MBES) backscatter and bathymetry data reveal new insights into the cliff-forming geologic units as well as largescale erosional processes on the Campeche shelf.
In 2013, the R/V Falkor collected MBES bathymetry and backscatter data sonars in the area of the Campeche Escarpment using Kongsberg EM302 30 kHz and EM710 70 kHz MBES systems. We use Fledermaus GeoCoder to process backscatter data, and ArcGIS to create mosaic of all survey lines. Fledermaus is then used to create a 3D representation of the dataset.
We delineate the escarpment into four geomorphic provinces based on submarine canyon density and morphology, as well as pronounced geomorphological differences formed in response to erosional processes along-strike of the Campeche Escarpment. Analysis of backscatter data reveals a high backscatter intensity unit comprising the steep cliff faces of the Campeche Escarpment. Due to the high backscatter intensity of the unit, we infer this to be a carbonate unit, which is also associated with the K-Pg boundary layer as previously reported by Paull et al. (2014) based on a steep bathymetric change and constrained by cores from DSDP Sites 86 and 94. Large-scale retrogressive-appearing erosion has left high-angle breaks where slabs of sediment have eroded the escarpment edge, thus giving the slope a terraced appearance. This erosion reveals higher backscatter intensity material overlain with remnants of lower backscatter intensity sediments within the slide scar. We infer the high backscatter intensity material to be carbonate layers on which erosion occurred. The stark contrast observed in MBES backscatter data between high intensity carbonate material and lower intensity sediments, refines and constrains the location of the K-Pg boundary layer exposed along the Campeche escarpment and provides new insights into the erosional styles of the Campeche escarpment.
MBES backscatter analysis is a low cost method that yields a more detailed assessment of surface material than bathymetry alone. This proves to be a powerful tool; enabling further inferences about geomorphic features and geologic characteristics of a study area, and as an efficient means of locating seafloor hydrocarbon seeps.