bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of Field Measurement and Advanced Analysis on Baldpate's Continued Service Integrity Management Plan
Authors: Moslehy Y. , Kemp D. , Kitson M. , Litton R. , Sheppard R. 
Published: April 2016

A Structural Integrity Management (SIM) program plays a substantial role in managing structural risks and reducing expensive deepwater in-situ repairs. Inspection and operating decisions and costs are significantly affected by what is defined in a SIM program. Baldpate compliant tower in particular features an innovative structural system and is among the tallest structures ever built. It is a valuable deepwater asset that needs a SIM program backed by a strong technical foundation to provide confidence that continued service and potentially expanded operations can be safely achieved.
Earlier studies had shown that fatigue sensitivities at critical locations could potentially limit Baldpate's useful life beyond the original 20 year target. This was mainly due to the conservatism inherent in the spectral fatigue approach which did not capture the innovative and highly dynamic features of the Baldpate tower. In order to better understand the dynamic characteristics of this unique structure and accurately model the tower, a field measurement campaign using 3D accelerometers was carried out. The measurements were then used to benchmark and adjust the computer model. A time-domain rainflow fatigue analysis was utilized to capture the compliant response of the tower for both fatigue seastates and three large storms which have affected Baldpate. This showed that fatigue sensitivities are not limiting factors for continued service of Baldpate, and the areas of fatigue sensitivity were incorporated into a long term SIM plan to focus future inspection and monitoring efforts.
This paper provides details on the study performed for the Baldpate structure using field measurement, a rainflow simulation and its contribution to the development of a long term, risk based SIM plan. The behaviors of several unique structural components, such as stress concentration factors at atypical connections, gap behavior and friction lock-up at the guided axial tubes, were also considered. SIM options for these unique structural components are discussed, including underwater inspection methods and on-site dynamic motion recording. These efforts resulted not only in a more promising range of fatigue lives than previously calculated, but also identified areas of focus in support of a risk based SIM and associated inspection plan to support continued service through the asset's viable economic life. This approach is enhanced by a real-time monitoring plan to measure the dynamic characteristics of the tower under different load conditions to indicate when certain unique structural characteristics (e.g., axial tube motion within the guides) would affect the fatigue life of critical joints in the Baldpate tower.
Design and Qualification of Direct Electric Heating Riser Cable for Deep Water Applications
Authors: Clasen Torunn Lund , Slora B. R. , Karlsen Stian 
Published: April 2016

Direct Electrical Heating (DEH) is a field proven technology for preventing wax and hydrate formation in subsea flowlines. The technology is currently in use for heating more than 30 flowlines ranging up to 42 km in length, and has been installed in water depths down to 1070 m.
DEH is an attractive solution for addressing flow assurance challenges in deep waters. One main challenge related to DEH in deep waters is to design a dynamic riser cable for supplying power to the subsea DEH system. The challenge is related to high topside tension caused by the weight of the cable, and the risk of overloading the conductors. This paper discusses the ongoing work related to qualifying a DEH riser cable design for deep water applications.
Eni's Global Program on Production Data Management Sets the Stage for an Effective Reservoir Management & Production Optimization System
Authors: Drago Antonio , Vignati Emanuele , Bergamaschi Barbara , Calzari Marinella , Morales Fernando L. , Fumey-Humbert Frederic , Toyas Christos 
Published: April 2016

The aim of an ongoing implementation of a global production management system is to support an operator in its continuous efforts to improve its affiliates' oil and gas field operations. The main objective of production operations is the maximization of the project returns, which involves the optimization of well production rates, increased of reservoir recovery, and the reduction of the associated expenses. This objective can only be achieved through the effective use of accurate information about the production system's performance (including its reservoirs, wells, and surface and process facilities).Due to the massive amount of information generated daily in oil and gas fields, specialized software tools are essential for data gathering, cleansing, and storing and for meaningful dissemination, consumption, and analysis of the data to aid decision making.Aware of this critical need, starting in 2008, Eni launched an ambitious program to implement a production data management system (PDMS) that allows specialists to properly perform well and hydrocarbon production accounting, run specific workflows to correctly analyze the information, and effectively support the operations in several key affiliates around the world.The interconnected system has proved to be very valuable for strategic planning and informed decision making, considering the size and the remoteness of the operations and the need to assure that operations in the assets are carried out in the most efficient way possible.The current scope of the PDMS global program includes completed implementations for 12 affiliates and the monitoring of more than 4,000 wells. This paper describes the program's objectives, the achieved benefits, and the vision on the way forward. The paper also addresses some of the main problems encountered during the execution and enumerates the main lessons learned.
Extending the Lifetime of Oil and Gas Equipment with Corrosion and Erosion-Resistant Ni-B-Nanodiamond Metal-Matrix-Nanocomposite Coatings
Authors: Murugesan Sankaran , Monteiro Othon R. , Khabashesku Valery N. 
Published: April 2016

The increasing pressure to eliminate hard chromium in oil and gas applications because of environmental concerns related to hexavalent chromium has fueled the need for substitutes with comparable economics and performance. Nickel (Ni) presents a viable alternative coating material, which is widely used in industrial applications over the past five decades because of its unique characteristics in improving resistance to corrosion, abrasion and wear. Performance of Ni-based coatings can be further improved with the development of metal-matrix-nanocomposite coatings (MMnC). This paper presents the development of a new class of MMnCs prepared by electrolytic deposition. The nanocomposite coatings are formed by the simultaneous impingement of the nanoparticles onto the growth surface and the envelopment of said particles by the depositing Ni ions. In this new process, the metal matrix comprises Ni-B compositions produced with a nontraditional Boron (B) source, which enables higher B-contents in the matrix, resulting in superior hardness and resistance to corrosion.
Incorporation of diamond nanoparticles into the matrix improves resistance to wear without negatively affecting the corrosion resistance. Dispersed nanodiamond decreases the grain size of Ni-B matrix and improves the mechanical properties of the coatings. Ultimately, size, nature and content of particles dispersed in the matrix determine the properties of the coatings. This paper describes the impact that Boron and nanodiamond incorporated in the matrix have on the growth, microstructure, corrosion and mechanical properties of the new class of metal-matrix nanocomposite coatings. Experimental results also show that this material outperforms current commercially available electroless Ni-B coatings. The novel coatings presented extend the lifetime of equipment used in corrosive and erosive environments in the exploration and production of oil and gas.
Achieving Savings Through Reliability Using Real Time Data
Authors: Pritchard David M. , York Patrick , Roye Jesse 
Published: April 2016

Abstract
Historically, the drilling industry has utilized real time data (RTD) for improving drilling efficiencies, documenting occurred events, and reactive decision-making. RTD should promote situational awareness with respect to wellbore instability and hazards. Drilling trends identifiable in RTD change over time as abnormal trends leading to hazards and rarely occur instantaneously. These destabilizing events such as cuttings loading, barrier compromise, kicks, pack-offs, wellbore collapse, or other mechanical and pressure-related causes, whether in rotating or flat-time operations, can be avoided or mitigated. Accepting these hazards as a necessary outcome of drilling operations can be a dangerous proposition and denies risk accountability.
Enhancing the systemic approach to process safety represents a paradigm shift in the industry and requires changing behaviors through proactively managing and controlling the pace of the drilling process. A new paradigm suggests the use of a deterministic, physics-based model of real time force-balance in the wellbore during the construction process. Identifying the trends of these forces become predictors of hazards. Mitigating and correcting the trends, in real time avoids process safety failures and consistently results in improvements in non-productive time (NPT) and removable lost time (RLT), notwithstanding the large associated costs. The drilling trend behaviors that predict hazards can facilitate leading as opposed to lagging Key Performance Indicators (KPIs). The new paradigm suggested enables hazards avoidance and thus significantly reduces the costs of drilling. This paper describes and explains these predictive techniques as well as offers suggestions for industry training with respect to surveillance and hazards avoidance using RTD simulators, much as airline pilots would use for continual training.
A Sensible Approach to Subsea Pipeline Route Determination – Moving from Hand-Drawn Routes to Geologically-Constrained, Least-Cost Optimized Paths
Authors: Devine Christine A. , Haneberg William C. , Lee Hoseong , Liu Meng-lung , Chang Gwo-ang 
Published: April 2016

Abstract
Pipeline routes have traditionally been selected in the early stages of prospect development, using low-resolution datasets, with minimal consideration for seafloor and shallow subsurface geological conditions, and rudimentary rules about seafloor gradients and pipeline curvature. We describe advantages of a modern GIS-based approach using least-cost path optimization over a composite geocost surface, which provides a structured framework for quantifiable decision-making, incorporates formal risk assessment as part of the route acceptance process, and forms the basis for a forthcoming industry guidance document. The workflow that we propose comprises: 1) geophysical data acquisition, geotechnical investigations, and geological studies during the initial stages of development to evaluate potential pipeline routes; 2) systematic evaluation of geological, geotechnical, ecological, and cultural factors that determine pipeline route suitability; 3) the classification and weighting of all identified geohazards and constraints to develop a geocost composite map; 4) determination of an optimal route using least-cost path optimization within a geographic information system; 5) risk assessment of the least-cost route; and, finally, 6) route acceptance. The classification and weighting of component hazard maps, as well as the risk assessment, are best performed collaboratively by a multi-disciplinary team that includes expertise in marine engineering geology, geotechnical engineering, pipeline engineering, marine ecology and archaeology, and health, safety, and environmental personnel. We will demonstrate a step-by-step application of the method, which has already been used for pipeline route determination on geologically challenging deepwater projects. If geohazards are not identified in early stages and used to guide route selection, changes to the original pipeline route or mitigation - either of which could affect schedules and budgets - may be necessary. This method is relatively new to subsea pipeline route determination, however, it offers important advantages over previous methods and can be applied starting in the earliest conceptual phases of field development, iterating if necessary, as new information becomes available.
Quest for the Perfect Dry Tree Application, Summary of RPSEA and DeepStar Projects over the Last 10 Years
Authors: Head W. J. , Pappas J. M. 
Published: April 2016

Abstract
Dry trees (DT) provide vertical well access from the water's surface with well bore tools, and are especially useful for speedy interventions. Lower potential CAPEX helps, thus avoiding some of the more complex deepwater seafloor construction projects. However, in the ultra-deepwater, risers for DT become the demons of necessity. Deepwater pressures and high formation temperatures make for thick walled pipe. All of this requires large, extensive kit, and a challenge for existing DT designs such as a spar or a tension leg platform (TLP).
Riser weight controls DT design choice. The common top tension machine is limited to about 35 feet of the up and down motion of the sea. When industry designed mobile offshore drilling units (MODU's) larger with deeper draft to offset vertical riser motion, the structure itself became a cause of unwanted motion and vibration. After hull considerations, research focused on structural vortex induced vibration (VIV) and vortex induced motion (VIM), riser motion onboard, and lower weight risers.
Deep draft designs studied by RPSEA and DeepStarTM showed VIM and VIV reactions through simulated computer and tow tank testing. Such designs require mitigation strategies. Paired column semisubmersible floating vessels (PC-Semis) can be designed with some control over column size as part of the mitigation. Critical steps to complete are as follows: Performance on the drill/production aspects, especially of the risers relative to fatigue, and safety in both normal weather and under extreme conditions.Well bay designs to allow simultaneous ongoing drilling operations while producing [with risers], and keeping the area safe for workers.
The results of nine years of study have shown that there were no major technical show stoppers. Since the original quest was to save money, the objective has become a more difficult moving target. Lessons learned suggest a possibility to use deep draft dry tree (DT) designs as less costly wet tree vessels.
Understanding Reservoir Fluid Dynamic Processes by Using Diffusive Models
Authors: Zuo Julian Y. , Mullins Oliver C. , Jackson Richard , Agarwal Ankit , Ayan Cosan , Wang Kang , Chen Yi , Pan Shu , Elshahawi Hani , Dong Chengli , Herold Bernd , Kumar Sanjay 
Published: April 2016

Abstract
Downhole fluid analysis (DFA) has successfully been used to delineate reservoir connectivity and fluid properties and to understand the origins of many complexities in oil reservoirs with the Flory-Huggins-Zuo equation of state (FHZ EOS). Equilibrium asphaltene gradients strongly imply reservoir connectivity, with fluid equilibration often taking tens of millions of years. However, reservoir fluids often demonstrate complicated compositional gradients from undergoing dynamic processes such active late gas charges, biodegradation, and water washing. In this paper, a simple 1D two-component diffusive model with analytical solutions is developed for taking into account dynamic processes in oil reservoirs. Two field applications of the developed diffusive model are active gas charging and biodegradation to better understand these dynamic processes.
In the first field application, an active late gas charge results in huge nonequilibrium gradients in several fluid properties including API gravity, gas/oil ratio (GOR), saturation pressures, and asphaltene content (color optical density) measured by DFA and surface laboratory analysis. Because the reservoir is not in equilibrium, these fluid property gradients cannot be modeled by the equilibrium EOS model. Thus, a diffusive model is needed to account for the large GOR gradient. The diffusive model predicts the large variations of GOR gradients successfully. The asphaltene gradient is evidently under control of convective currents induced by the gas charge. The exact nature of this process is currently under investigation. The asphaltene gradient is consistent with the predictions by the FHZ EOS with the assumption of asphaltenes locally in equilibrium with the local fluids described by the diffusive model.
The second field application is biodegradation occurring at oil/water contact (OWC). Compared to the predictions of the FHZ EOS, it is observed that the upper half of the oil column follows an equilibrium asphaltene distribution well. However, a much larger asphaltene gradient is found in the lower half of the reservoir, which gives rise to a huge (8×) viscosity variation and affects production. The measured asphaltene distribution in the whole oil column can be described nicely by the diffusive model along with the FHZ EOS. The diffusion of alkanes to the OWC (where they are rapidly consumed) is a control step. The consumption of alkanes at the OWC reduces the oil volume and increases asphaltene content and viscosity. Petroleum system modeling predicts initiation of reservoir charging in the Eocene matching the diffusive times required in the FHZ EOS modeling.
Source Control is a Viable Solution for Shallow Water Blowouts: Case Histories and Discussion
Authors: Derr Douglas , Cramm Carl J. , Garner John. B. 
Published: April 2016

Abstract
This paper presents two case histories providing insight into source control operations at shallow water depths. The first case history discusses a capping procedure at the seabed in a water depth of 80 ft. Debris on the seafloor was cleared and a new platform was installed, incorporating the remaining legs of the damaged previous jacket up. Once the well was successfully capped and diverted, the drillstring was snubbed into the flowing well, which was then killed by means of a dynamic kill operation. The second case history discusses capping a burning high pressure gas well on a platform. Debris was cleared and removed from the platform, and eventually the well was capped and flowed to a pipeline.
This work highlights how source control options should be considered and evaluated as part of emergency response plans for jackup rigs and platforms. Proper planning, organization, and task management are fundamental to a safe and successful operation.
Exploring Deep Water Applications for Offshore Renewable Power Systems
Authors: Worrall P. 
Published: April 2016

Abstract
The increasing power output of today’s renewable energy generation devices mean there is a growing need for affordable, dynamic, high voltage subsea power cables. Serendipitously, these solutions are directly relevant to the offshore oil and gas industry, specifically when coupled to power distribution hubs for processing and boosting at the evolving subsea factories.
It’s been challenging for the industry to identify an affordable and yet highly reliable solution that provides high power, deep-water, long length subsea power cables capable of continuously flexing. The entry of new dielectrics for higher alternating electrical stress means there are now solutions for these technologically complex and incompatible demands. However, both direct current (DC) and alternating current (AC) systems have benefits and limitations when used for offshore power systems.
DC systems offer a proven solution to transmit high power over long distances between two points. Yet, DC systems are neither ideal for multi-node topologies nor for end-to-end connection, especially when including conversion of mechanical energy into electrical energy (generation), switching, connectors, protection and final conversion of electrical energy back into mechanical work (eg motors). AC systems offer the possibility of easy and efficient conversion and delivery using the most appropriate voltage across each selection of the network, from the generation through transmission, distribution and control, all the way through to the voltage needed by the motors and other loads at the far end.
This paper will significantly advance research and development efforts in dynamic subsea power cable technology and help progress offshore renewable energy technologies by championing the consideration of system needs before cable design. It discusses the benefits and limitations of alternative cable designs for subsea power links, supported by results from sample and full scale testing of a 72 kV subsea cable design, using concepts suitable for dynamic application. The International Council on Large Electrical Systems (CIGRE) and the International Electrotechnical Commission (IEC) are considering creating standards and this paper proposes a basis for this.
Guidance for Grouted Sleeves in Repair of Offshore Installations
Authors: Alwis N. C. , Dier A. F. 
Published: April 2016

ABSTRACT
This paper provides new guidance on the use of unstressed grouted sleeves in strengthening/ modification/repair (SMR) applications. Presently there is no guidance for the slip capacity of grouted split sleeves having longitudinal bolted flanges, and the available guidance for continuous sleeves (as used in pile-sleeve connections) requires modification to make it applicable for split sleeves. The investigations detailed herein encompass the effects of both axial loading sense (tension or compression) and connection details (weld beaded or plain pipe).
It is necessary, when examining the slip capacity of grouted components, to use test data. A database of continuous and split sleeve test results was therefore compiled, verified and subjected to screening procedures. Available codified provisions for pile-sleeve connections have been checked against the database, and shortcomings have been exposed for extension to SMR applications. The screened database was then interrogated further and enhanced guidance provisions were derived to address the shortcomings, in particular for split sleeve pipe connections.
The results confirm that the latest existing guidance for slip capacity of pile/sleeve connections is suitable for such components with a caveat on plain pipe connections under tension loading. For continuous grouted sleeves in SMR situations, the same guidance can be used. For split sleeves, the reduced hoop stiffness due to the presence of longitudinal bolted flanges usually leads to lower slip capacities than equivalent continuous sleeve specimens. New guidance is presented in this paper to cover such connections.
The Prediction of Fretting Fatigue in the Pressure Armours of Dynamic Flexible Pipes
Authors: O'Halloran Sinéad , Harte Annette , Connaire Adrian , Leen Sean 
Published: April 2016

AbstractThis paper presents a combined experimental and computational framework for the design of flexible marine risers against fretting and fatigue. The framework is based on: (i) a suite of laboratory experimental methods for fretting and fatigue tests, and (ii) a global-local methodology for flexible riser analysis including dynamics and frictional contact mechanics. The effect of coefficient of friction on the predicted substrate stress distributions and fatigue life of the nub-groove region of flexibles has been investigated. It is shown that coefficient of friction has a significant effect on predicted trailing-edge tensile stresses in the pressure armour layer and, hence on fretting crack initiation in risers. The framework should assist in the design of pressure armour layers in flexible marine risers against fretting wear and fatigue.