bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Paraffin Wax Inhibitors: An Experimental Comparison of Bench-Top Test Results and Small-Scale Deposition Rigs for Model Waxy Oils
Authors: Perez Peter , Boden Eugene , Chichak Kelly , Kate Gurnon A. , Hu Lishun , Lee Julia , McDermott John , Osaheni John , Peng Wenqing , Richards William , Xie Xiaoan 
Published: April 2015

Abstract
The performance of paraffin inhibitors from several chemical families was evaluated using two model waxy oils in bench-top tests such as cloud point and pour point, and in small-scale deposition rigs using a cold finger and a flow loop. In addition, rheological characterization of the inhibited systems was conducted to provide additional insights into the function of the paraffin inhibitors. Similarities and differences in the response of the model oils to the paraffin inhibitors are discussed along with the correlations between the results from bench-top tests and the observed wax deposit inhibition performance.
The model waxy-oils were formulated using blends of commercially available waxes dissolved in a paraffinic solvent or a mixture of paraffinic and aromatic solvents. The wax blends were chosen to represent a broad range of carbon number distributions including one highly polydisperse distribution with an extended distribution of high carbon number waxes exceeding C50. Candidate paraffin inhibitors were initially evaluated for their impact on cloud point and pour point in these model oils. Subsequent testing of the inhibited systems included rheological characterization over a range of temperatures, cold finger deposition tests and flow loop deposition tests in a pipe-in-pipe geometry. All results are compared to the baseline results for the uninhibited model waxy oils.
While changes in cloud point and pour point gave a good indication that a particular paraffin inhibitor was impacting the wax crystallization process, this did not guarantee a significant reduction in deposits of the inhibited system. Moreover, the experimental conditions used in the small-scale deposition tests also affected the observed performance of paraffin inhibitors, indicating that temperature gradients (i.e., oil temperature and coolant temperature) must be optimized to achieve the highest discriminating power. This study highlights the degree of correlation and the areas of departure between bench-top test results and the main objectives of deposit reduction, and yield stress reduction in flowing systems. It also discusses the advantages and risks of using only the bench-top test results for the selection of paraffin inhibitors.
Lifetime Extension of Flexible Risers: A Generic Case Study
Authors: Leira Bernt , Berge Stig , Løtveit Svein-Are , Fergestad Dag , Langhelle Nina 
Published: April 2015

AbstractThe number of flexible pipes in operation is increasing due to new field developments and the desire to extend the lifetime of existing fields. There have been many challenges with respect to long term operation of such pipes, in many cases with the need to replace or repair before the end of the initial design life. The number of identified failure mechanisms and observed failure events is also increasing.The objective of the present paper is to describe the steps required in order to be able to extend the lifetime of a flexible riser for the case of corrosive annulus environments. A specific riser configuration is considered, and the particular case of outer sheath damage is applied for the purpose of illustration.
Multi Scales Exploration Strategy - Example of Research For Hydrothermal Mineralization in the French EEZ of Wallis and Futuna
Authors: Fouquet Y. , Scalabrin C. , Alix A.S. , Donval J.P. , Dupré S. , Guérin C. , Guillou M. , Guyader V. , Konn C. , Patriat M. , Pelleter E. , Pierre D. , Rosazza F. , Saint-Laurent X. , Dyment J. , Szitcar Florent 
Published: April 2015

Abstract
As part of a Public Private consortium, explorations to locate sulfide mineralization in the French EEZ of Wallis and Futuna allowed to discover new hydrothermal fields. Three cruises organized between 2010 and 2012 have explored this area. The first phase focused on a regional mapping to find areas of recent volcanism using multibeam echosounders and acoustic imaging. Hydrothermal plumes produced by high temperature hydrothermal activity were located using chemical and physical anomalies in the water column. Using a CTD/rosette we collected water samples and measured physical parameters. Onboard methane and manganese concentrations and physical parameters studies helped to locate active fields with a precision of about 5 km. Physical anomalies caused by the hydrothermal plumes were also recorded by analyzing the multibeam backscattered signals of the water column. In a second phase, an AUV, operated at 70m above the seafloor, helped to establish high-resolution (1 m) bathymetric maps on targets identified during Phase 1. Near seafloor, magnetic anomalies were recorded using a deep magnetometer on the AUV. Analysis of AUV acoustic signals in the water column allowed to find the vertical part of the hydrothermal plumes and to pinpoint areas of fluids discharge with a precision of a few meters. During the third phase, manned submersible dives were conducted on the hydrothermal fields to study the hydrothermal fluids, the different types of mineralization and associated ecosystems. This multi-scale strategy allows gaining considerable time in exploration, and led to the discovery of several hundred of active and inactive fields and associated sulfides mineralization on an area not previously mapped. The AUV high-resolution mapping and detection of vertical plumes and inactive chimneys can thus be considered as a missing link of the exploration strategy to locate hydrothermal deposits.
DP Design Philosophy and Planning for Assurance Success
Authors: Bateman Mat , Maritime Global , Wallace Peter 
Published: April 2015

Abstract
Many marine activities require a marine vessel to remain stationary or move in a precise and controlled manner. Dynamic Positioning (DP) is the technology that enables this by by means of automation and specifically designed station keeping systems. DP is used in the energy industry for upstream and downstream activities ranging from exploration (e.g. core sampling), construction (e.g. pipelaying), drilling (e.g. drillships and semi-subs), production (e.g. supply vessels or well workovers), or downstream (e.g. shuttle tankers). DP has moved from novel concept to commonplace.
DP can be characterized as being medium-to-high complexity and tightly coupled; this means the potential for downside consequences are always present and can come from any number of directions with little or no warning. The marine industry is adapting to this higher level of complexity and coupling combined with a mixture of goal based and prescriptive standards.
There are many perspectives with respect to DP requirements coming from different regulatory agencies, Class Societies, charterers, operators, general public, other stakeholders and precedent established by industry practice. These different perspectives create an environment for ambiguity and misunderstanding on the true DP capabilities of the vessel. Getting this wrong can lead to poor performance that can amount to considerable frustration for all involved.
Getting DP right gives us a vessel that enables us to do more, in more in increasingly difficult environments with lower downside risk exposures and better managed consequences when compared to non-DP vessels.
The purpose of this paper is to outline a three-step process that makes sense of the different perspectives and provides a framework to technically deliver a vessel that meets these expectations. The three phases are the following: Establish the risk tolerance and design intent of the vessel.Establish the DP design philosophy. This sets the design and engineering requirements to build and operate a real vessel for real projects that meet the design intent within the risk tolerances.Design for Assurance. Consider and manage the assurance and control aspects of the design, equipment, systems and total vessel with respect to DP during the life cycle of the vessel.
Lessons Learned and Safety Considerations for Installation and Operation of a Managed Pressure Drilling System on Classed Floating Drilling Rigs
Authors: Patel Harish , Bruton Jay , Dietrich E. , Prince-Wright R. 
Published: April 2015

This paper will discuss the review, integration assessment, engineering analysis, and process safety analysis carried out prior to installing a managed pressure drilling (MPD) system on a classed floating mobile offshore drilling unit (MODU). MPD techniques have proven cost-effective, reliable, and safe when drilling difficult onshore wells, as well as drilling from MODUs with a surface blowout preventer (BOP). However, the implementation of MPD on deepwater wells has been hampered by industry inertia and questions about reliability, barriers, riser gas management (RGM), and general riser interface issues. This paper will focus on those distinctly different aspects introduced by MPD while drilling from a floating MODU. The primary objective will be to highlight how innovative application of MPD can enhance safety when drilling challenging wells in deep water.
Additional insights are provided regarding experience from several MPD installations on deepwater rigs around the world that have been tasked with drilling challenging wells.
The process employed in these discussions are mainly centered on the following major categories of MPD equipment and methods:
Installing and operating a rotating control device (RCD) below the ocean's surface, including integration with a riser gas handling device.
Redundancy and fail-safe considerations for valving, both for flow lines and control lines.
Piping, umbilicals, and hoses in the moon pool area.
Nodal safety assessment of the system.
An Operator-Contractor-Service Company ‘bridged’ well control philosophy.
The procedures will recount safety considerations of equipment classifications and system certification for MPD systems used on deepwater rigs.
The lessons learned during this project help to establish a baseline for standardizing MPD drilling equipment and systems for global applications. The knowledge gained also was instrumental for the classification society certifying this equipment and system to develop safety and certification requirements aimed at improving MPD safety on deepwater drilling units.
This paper will outline the core steps taken to achieve classification of an MPD system for a MODU, as well as enable increased utilization of MPD methods in deepwater wells worldwide. Class and certification can provide greater confidence to offshore operators that they can commission drilling equipment and systems capable of delivering safer, more dependable MPD wells, some of which may be considered un-drillable using conventional methods.
Improving Drilling Success by Integrating Sedimentology and Diagenesis models: Case Study from South America
Authors: Ait-Ettajer Taoufik , Fontanelli Laurent , Mookanahallipatna Lakshmikantha 
Published: April 2015

Summary
The improvement of the success of the well drilling is an important task during the development of hydrocarbon reservoirs, and the use of three dimension mechanical earth model (MEM) is key to predict the behavior of drilled well and to prevent damaging the well. The MEM encapsulates several information related to pore pressure, mechanical properties of the reservoir rock, the geometry of the reservoir limits and the overburden and the stress regime. Various workflows were proposed to build and update the MEM. However, those approaches do not incorporate the complexity of the carbonate rocks. In fact, the carbonate rocks, hold heterogeneous pore systems that impact the rock strength and the pore pressure behavior. The heterogeneity of the pore systems is due to the specificity of the deposition process of the carbonate rocks, mainly composed of fauna and or flora, and the rate of diagenesis.
In this paper, we propose a workflow that improves the modeling of the mechanical properties for carbonate reservoirs. This workflow starts by reconciling data at different scales, diagenesis rate at thin-section scale, scratch and laboratory strength tests at plug scale, electrical logs at well scale, and three dimension sedimentology and seismic volumes at reservoir scale. The second step is to establish the relationship between the mechanical properties, the pore pressure, the seismic attributes, the sedimentology and the rate of diagenesis. The last step allows interpolating and assessing the uncertainty of the mechanical properties and pore pressure in the three dimension reservoir model.
The workflow was applied to an off-shore carbonate field in South-America. It showed that there is a strong relationship between the type of fauna and flora, composing the carbonate rock, and the rock strength and pore pressure. The three dimension mechanical model, at hundred meter horizontal resolution and one foot vertical resolution, allowed to quantify the risk associated with the drilling of the previously planned wells, to improve the location for future drilling wells and to optimize the drilling parameters such as mud weight.
Dynamic Calibration of the Empirical Pore Pressure Estimation Methods Using MPD Data
Authors: Rostami S. Ameen , Kinik K. , Gumus F. , Kirchhoff M. 
Published: April 2015

Abstract
Pore pressure (PP) is one of the most critical parameters in geomechanical analyses of wellbore stability along with well planning. Several empirical methods aim to estimate the pore pressure using seismic and logging while drilling data, and drilling parameters. Considerable number of studies addressed the uncertainty in the PP estimate using these methods due to noise and fluctuation in the received data as well as under compaction effect in over-pressured formations. It is common practice to calibrate these methods with data from Repeat Formation Tester (RFT) or Drill Stem Test (DST). Managed pressure drilling (MPD) allows precise measurement of the PP with dynamic pore pressure testing (DPPT), reducing the non-productive time inherit in RFT and DST without compromising operational safety.
This paper presents methodology to calibrate the available pore pressure prediction methods using dynamic PPT data. Presented methodology involves comparison of several correlations and selection of the one with the best fit to the dynamic PPT data, and determination of the formation-specific correlation coefficients using regression analysis. The work includes validation of the method on case study example. The technique implemented in a new MPD control software platform for real time analysis of the dynamic PPT data to forecast the pore pressure of the following formations while drilling.
Forward Predictions for Life-of-Field Assessments Based on the Observed Lateral Buckling Behavior of Operating Deepwater Pipelines
Authors: Sriskandarajah T. , Roberts Graeme , Tanscheit Peter , Solano Rafael F. , Hansen Alexandre , Antunes Bruno R. 
Published: April 2015

Making forward predictions of a pipeline's behaviour from an operational base state requires a working knowledge of the pre-existing stresses and strains. To gain this working knowledge for a pipeline that has undergone lateral buckling requires either an engineering assessment that can accurately predict the displacement of the pipeline on the seabed, and from which the operational stresses and strains can be estimated and extracted, or instrumentation on-board the pipeline that records stress and strain information which can be uploaded and sent back to the analyst.
Whilst it is hoped that the pipeline analysis carried out in design stage be focused and accurate enough to capture and present the required data for life-of-field assessments the reality is otherwise. The purpose of the design strategy would have been to attain code compliance and the required safety level for the pipeline system, which are targets that may be at odds with predicting most realistically the pipeline's state in the operating condition. This is a result of the design needing to accommodate multitudinous conservative assumptions about the pipeline geometrical properties, the seabed profile, operating pressure and temperature profiles, as-laid out-of-straightness and pipe-soil axial and lateral resistances and also the need to attend to code requirements which will have their own partial safety factors embedded. It must be admitted, reluctantly, that the pipeline response realized in the field may never be an accurate reflection of the outcome of the design process.
This paper presents data pertaining to the surveyed as-built configurations of deep water HP/HT pipelines and a small diameter piggyback pipeline and a method for making forward predictions from such pipelines about their observed base states. The information contained in the paper may be used as input to future design strategies or as key considerations for the successful completion of such re-analyses by other operators, contractors and consultancies.
Adapting Aerospace Technology to DP Vessels for Safe and Stable Station Keeping
Authors: Hickey Mark , Morton Russell , Lund Chris , Galligan Dan 
Published: April 2015

Abstract
The requirements for aerospace positioning and a system for DP vessels have much in common. Both markets are mature yet there has been very little technology transfer between the two disciplines. Both have the same concern for safety of life and need the three "Rs": Resiliency, Reliability, and Robustness.
Why hasn’t there been more technology exchange between marine and aerospace? There are probably two key reasons. First, there is a different approach to regulations and rule setting. Second, the physical difference of the platforms requires that aerospace employ the latest technology to reduce the size, weight, and power consumption; to improve the total performance and safety of the platform. This paper will only focus on the second reason.
According to a United Kingdom (UK) Department for Business, Innovation, and Skills (BIS) (https://www.gov.uk/government/groups/bis-aerospace-marine-and-defence-sector-team#marine) the UK marine sector generates over £10 billion turnover and employing nearly 90,000 people while the Aerospace sector has a turnover of £24 billion and supports 230,000 jobs. Some of the investment in Aerospace can benefit DP applications. This paper will discuss the integration of an aviation INS and integrated GNSS augmentation technology that was developed for docking the space station. This INS is several years old, well tested and proven technology, that is keeping millions of people safe each day.
Offshore, there is an opportunity to take it one step further by integrating an acoustic positioning system to improve the resilience of the total system. We will talk about how the INS can use one, two, or three aiding sources and what happens if one or two of the aids drop-out.
Assessing Uncertainty in Hydrocarbon Volumes with Application of a Workflow on a Field
Authors: Schnetzler E. T. 
Published: April 2015

Abstract
A probabilistic workflow is presented on a real field to study both local and global uncertainty of in-place hydrocarbon volumes. Different products are generated, designed to help with specific questions and decisions. A picture of the global uncertainty helps drive large scale decisions such as selling or retaining a lease. The local uncertainty view relates to questions of well drilling and planning. Finally, looking at the contributions of each source of uncertainty helps decide what additional data to collect in order to reduce the global uncertainty.
Welding Robot Repairing Subsea Pipelines
Authors: Berge Jan Olav , Armstrong Mike , Woodward Neil 
Published: April 2015

Abstract
Offshore oil and gas pipelines are important assets for maintaining stable energy supply as well as being critical for maintaining cash flow to the owners and shippers.
Emergency repair response time is in focus by all major pipeline operators, and the need for remote repair technology has been addressed since the mid 1990s. Statoil have, on behalf of the Pipeline Repair and Subsea Intervention (PRSI) Pool in Norway, developed new technology allowing remote controlled repair by hyperbaric welding of large diameter subsea pipelines in water depths down to 1300 meters.
The new Remote Welding System consist of three main modules; a habitat providing a dry gas filled work location at the tie-in location, a power and control unit launched separately providing all essential services needed for the job and the remote welding tool performing the welding operation itself.
The system is built and qualified for pipelines from 30" to 42" diameter, but may be expanded to smaller diameters and deeper waters.
A Dynamic Positioning MODU Critical Control Systems Communications and Software Reliability Assessment
Authors: Savoy Steve , Wilson Richard , Dewitt Cris , Romero Matt , Morgan Christopher 
Published: April 2015

Abstract

Objectives/Scope
Deepwater drilling units utilize critical Industrial Control Systems (ICS) that may be vulnerable to malicious software attacks. These systems include Dynamic Positioning, Vessel Management, BOP and Drilling Control. Dynamic Positioning Systems are critical to deepwater operations and many software failures pose a risk of environmental and/or economic impact. The objective is to assess a Mobile Offshore Drilling Unit (MODU) systems architecture and communication connections for the possibility of unauthorized access. A review of Software Management of Change (SMOC) procedures as practiced on these vessels is included to determine adherence to any existing procedures or policies.

Methods, Procedures, Processes
The vast majority of control systems contain dedicated embedded processors. These processors use operating systems that have an extremely low risk with regard to common malicious software. However, many systems have operator Human Machine Interfaces (HMI) that use Microsoft Windows or other vulnerable operating systems. These operating systems represent a risk of vulnerability if not managed appropriately. Newer processors or consoles have USB ports and/are connected via Ethernet or similar communication links that provide an entry point for unauthorized software. There are some systems that connect via remote communication links over the Internet for system data extraction and/or troubleshooting. If these communication links have not been validated as secure, unauthorized access is possible.

Results, Observations, Conclusions
This paper will present successes in other industries, how they apply to offshore assets, and prioritized areas of a rig's critical control systems. Demonstrated performance of a rig assessment (case study) on one particular unit is presented and how United States (US) and International standards and methods were applied is addressed. Results of the assessment and the remedial actions taken are presented. Relevant standards or methods for conducting an audit are reviewed.

Novel/Additive Information
Approaches to software reliability management including an "assessment template" that may be applied to a similar unit or production facility are included.