bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparing Offshore Facilities for Seismic Events
Authors: Sheppard Robert , Carson Patrick 
Published: April 2017

Abstract
Seismic design approaches for offshore assets focus on structural response, with the ultimate goal of preventing catastrophic collapse under intense ground motions. This is a prudent approach and places the emphasis on life safety. However, it does not address the operational and safety aspects of nonstructural component response. It is possible that a facility can survive an earthquake with little or no structural damage but be unsafe to man or unable to operate due to damage to the equipment and systems supported by the structure.
After the Gulf of Mexico hurricanes, Ivan, Katrina, Rita, and Ike, in the 2000s, it was recognized that topsides damage to permanent equipment was a significant problem for offshore assets, and guidance was produced by the industry to proactively address the issue. While there have been no significant earthquake impacts on offshore assets in seismic regions, there is still a need to prepare for their occurrence so that damage can be prevented.
This paper addresses the seismic vulnerabilities of mechanical, piping and electrical systems and equipment on offshore facilities and how operators can prepare their assets to safely withstand earthquakes with limited interruption to operations. The approaches presented build on the experience of the onshore power generation industry and field investigations of earthquakes impacts on industrial and commercial facilities going back over 40 years. Emphasis is placed on practical investigation of vulnerabilities, and mitigations to limit the kind of damage that is known to occur for various equipment types.
Applying Real Time Data Analytics to Early Detect Underreamer Failure During Hole Enlargement While Drilling at Deepwater Gulf of Mexico
Authors: Wu Xianping , Liu Yu , Martinez Manny 
Published: April 2017

Abstract
Deepwater drilling often requires simultaneously hole-enlargement-while-drilling (HEWD) to improve project economics and preserve hole size for reaching deep reservoirs. The challenge of having two active cutting structures (drill bit and expandable underreamer) in one BHA is improving ROP performance of entire drilling system while preventing premature failure of the underreamer, which is susceptible to vibration induced damages. From an operational standpoint, one potentially disastrous scenario is when underreamer has been severely damaged, but the drill bit is still in good condition. If such situation is not detected promptly and drilling continues, HEWD operation could potentially create a significantly undergauge hole section whose diameter is similar to drill bit. Such consequence can cause enormous difficulty for running/cementing the casing string, and often result in costly remedial operations, or in severe cases, hole abandonment.
To mitigate this risk, an advanced data analytics method was developed to early detect the failure of underreamer by utilizing the standard drilling mechanics data from both surface and downhole sensors. This patent-pending method includes the development of new performance metrics for underreamers based on rock cutting physics and cutter wearing mechanism. This new technology enables the operator to extract insights from similar tool failures in historical data and puts those insights into action on real-time data "in motion". A warning flag can be displayed immediately when the underlying failure pattern is detected by the new method. All relevant rig and office personnel are notified in real-time to promote timely discussion and facilitate decision making.
The operator working in Gulf of Mexico required hole-enlargement-while-drilling to open a pilot hole from 16.5″ to 20″ from 14,000′ MD to approximately 21,000′ MD. The new technology was utilized to monitor the underreamer performance in real-time for this challenging section. The technology provided a warning signal as soon as the algorithm detected the onset of a failure pattern from the underreamer at about the midpoint of the section. When it was pulled to surface, underreamer showed significant damage on cutting structure and had started becoming undergauge. This case study demonstrated the validity of this new method in detecting underreamer failure in real-time. Since then, this technology has been deployed on more than 10deepwaterwells to mitigate the risk of underreamer failure.
Meeting the Demand for Barrier Plug Integrity Assurance & Verification of Well Abandonment Barriers
Authors: Stein Arild 
Published: April 2017

Abstract
Well barrier installation practice is dictated by territoryspecific regulations which are largely based on historic practices. However, emerging technologies, tighteningnationalregulations, and demands from assetowners are gradually affecting the way we carry out our intervention operations. Driving the technology development is time saving but with a sharp eye on safety. Well documented verifications on temporary barriers and barriers installed for well suspension and future P&A barrier installation is expected. There are multiple issues involved in gaining proper verification of aninstalled barrier. One major issue appearing is the general condition and status of previously installed plugs and valve components in older wells, which canresult intwo wellbore barriers installed in close proximity. Othermajor issues are the well'sgeneral ability to support an inflow test, and the time it takes to get asegregating well stable.
Riserless Light Well Intervention Restores Production on Oyo - 8 Subsea Well
Authors: Adenipekun Adedokun , Marinho Gregory , Odeyemi Olushola , Ugboaja Chidi , Bassey Ayoge , Nnebocha Ezinne , Ade-Aina Oladeji 
Published: April 2017

Abstract
Producing hydrocarbons in a deepwater environment is quite challenging and the goal is always to sustain production for as long as possible. Any shutdown, whether intended or unintended, can prove costly. Such was the case on Oyo-8 when the down-hole safety valve failed to open after a planned production curtailment. The several attempts to open the valve were unsuccessful due to suspected loss of hydraulic communication to the operating mechanism or the malfunction of the mechanism. A well intervention was therefore deemed necessary to re-enter the well.
Well intervention in a deepwater environment is particularly expensive, risky and complex, whether it is rig based or rigless. A vessel based riserless light well intervention (RLWI) operation was determined as the optimal solution for Oyo-8. This entails a through-tubing operation to install a retrofit sub-surface controlled safety valve (velocity valve) assembly across the tubing-retrievable safety valve (TRSV) to permanently hold open its flapper and serve as a sub-surface controlled safety valve.
The notable advantages of a vessel based operation were the reduced personnel and reduced number of third-party service contractor interfaces to manage. The rig-up is significantly simpler than the requirements for rig-based completion/de-completion operations. The fact that it is riserless also eliminates the debris management issues usually associated with the marine risers of mobile drilling units. The key components of RLWI are the subsea well-control package, subsea wireline lubricator, subsea pressure-control head, a compensated winch mounted on a module-handling tower, compensated heavy-duty over-side crane, slickline unit, and two work-class ROVs.
The RLWI operation was completed within the budgeted time with less than 3% nonproductive time. The recovery of the horizontal tree crown plugs was uneventful, as the ROV high-pressure jetting tool was effective in flushing out debris from the top of the upper plug before installing the well control package and carrying out the slickline runs. The velocity valve assembly was installed hanging off the end of a thru-tubing packer set in blank tubing. A carefully planned combined operation with the FPSO ensured that control of Oyo-8 horizontal tree was maintained during well intervention from the production topside.
The intervention operation achieved the set objectives of restoring Oyo-8 to full production within allotted time and budget without any QHSE incidents. The RLWI operation was the first of its kind in Nigerian waters.
Nano-Enhanced Elastomers for Oilfield Applications
Authors: Dolog Rostyslav , Ventura Darryl , Khabashesku Valery , Darugar Qusai 
Published: April 2017

Abstract
The use of elastomers in oil industry extends over a broad range of applications including seals, packing elements, reactive rubber elements, stators, and pads. These applications require a variety of property requirements that may differ for dynamic and static applications or include a need for stimuli-responsive capabilities in certain tools.
This research details the effect of nanofillers on elastomer properties for oil and gas components. The effects include enhancement of mechanical properties, wear resistance, thermal conductivity and heat expansion properties. In addition, effects of nanofillers on rapid gas decompression (RGD) resistance, chemical resistance to downhole fluids, and resistance to chemical aging at downhole temperatures were investigated.
Advanced rubber nanocomposites formulations, based on Hydrogenated Nitrile Butadiene Rubber (HNBR) elastomers, were designed internally. Their properties were assessed using methods and techniques to qualify elastomers for downhole applications. Mechanical properties of elastomers were evaluated at room temperature and at 325° F, which is a maximum application temperature for HNBR elastomers. RGD testing was conducted according to ISO standards.
Results indicated that it is possible to control mechanical properties of elastomers with nanotechnology, including improving the abrasion resistance of the elastomers by more than 100% in dynamic, wear-intensive applications, when compared to commercial compounds typically used in the oil industry. Thermal conductivity was improved by up to 40%, while heat expansion decreased by 30%, providing more versatility for seal design in dynamic applications which are prone to localized heating. In addition, RGD resistance in nanocomposites was examined and compared it to control samples. The industrial scale feasibility for nano-enhanced elastomers was demonstrated by a scale-up study.
Recent Improvements in Subsea Wellhead Fatigue Monitoring Algorithm and Accuracy Using Verification and Calibration Techniques
Authors: Ge Michael Long , Kebadze Buba , Henderson John , Zakeri Arash 
Published: April 2017

Current subsea wellhead fatigue monitoring systems typically measure subsea BOP stack response and convert accelerations directly to the stress on various critical wellhead components using transfer functions. The veracity of this process relies on the accuracy of input data and the numerical modelling of the riser, subsea stack and wellhead conductor system. Poor representation of a real system could potentially yield an inaccurate calculation of transfer functions and consequently, imprecise estimation of the stress levels and predicted fatigue damage. The transfer function is strongly influenced by subsea stack system stiffness, which depends on dynamic soil response, stack hydrodynamic added mass and drag, location of the subsea stack fixity point, and stack-conductor system characteristic frequency. The latter two can be measured in the field and compared with predictions from numerical models. This paper evaluates the subsea wellhead fatigue monitoring algorithm and accuracy using verification and calibration techniques with field measurements. Important considerations for verification and calibration (e.g. soil property) are also discussed.
The new approaches described are applicable to fatigue monitoring and analysis of subsea wellhead and conductor systems in both shallow and deep waters. The approaches presented herein could improve determination of the conductor fixity point and subsea stack characteristics, which in turn, would help in accurately determining wellhead fatigue and extracting displacements if needed. The good match between predicted and measured values of these parameters demonstrates that the numerical model and associated transfer functions are adequate for measured fatigue damage estimation.
The transfer functions for fatigue monitoring systems and the associated subsea wellhead fatigue results could be significantly affected by the accuracy of the modelling methods and input data, particularly the soil properties. An inacccurate representation of the distance between the sensor and wellhead hot spot locations from which the transfer functions are derived could affect the accuracy of the fatigue results. For the case presented herein, the hydrodynamic properties drag loads and added mass have a less significant effect on the accuracy of transfer function and fatigue results.
Comparison of Current Measurements from Oceanographic Mooring and Unmanned Surface Vehicle
Authors: Yazarov Maxim , Pai Sudhir , Quiniou-Ramus Valerie 
Published: April 2017

Abstract
Monitoring of currents is of high importance for Oil and Gas industry, especially when it comes to design, offload and support to operations. Various monitoring techniques, existing nowadays, with each having their own pros and cons, are briefly discussed in the paper.
The objective of study was to compare current data acquired by Unmanned Surface Vehicle (USV), used offshore South America East Coast to support seismic acquisition survey in 2013, to the ones measured by conventional oceanographic mooring (COM) deployed in the same area. Consistency of these datasets was investigated. Efficiency, flexibility and applicability of "static" (mooring) versus "dynamic"(USV) solution for current monitoring applications are discussed.
Data analysis started with plotting time series of current speed at selected depth levels. The quick comparison made it possible to discuss data comparability and current speed and direction patterns. The analysis was followed by establishing scatter diagrams, directional distributions and Quantiles-Quantiles plots, which in turn made it possible to conclude on overall data representation, consistency and agreement.
USV are relatively new in Oil and Gas industry. Its advantageous feature of being a lowcost, autonomous and quite flexible solution makes them extremely promising for applications in the industry. Positive results from a comprehensive statistical comparison of the datasets showed that it is possible to accurately collect the current data by means of USV, meaning that USV can be considered alternative to conventional oceanographic mooring. Some recommendations on suitable use of each of the techniques are provided following the conclutions from the study.
Transforming Decommissioning Planning
Authors: Esson Roger 
Published: April 2017

The decommissioning of offshore oil and gas infrastructure is a key aspect in the life cycle of the facility and incurs a significant amount of cost.
Decom North Sea was formed in 2010 with funding from the UK Department of Energy and Climate Change (DECC), Scottish Enterprise and Highlands & Islands Enterprise (HIE) to focus on developing a robust supply chain that could deliver decommissioning. Since that time the organisation has moved to being fully funded by its members and has grown to have a membership in excess of 400 from the UK, across Europe and internationally.
Only a small proportion of the UK Continental Shelf having been decommissioned, to date and current estimates predict expenditure to 2025 approaching £18bn (Oil & Gas UK Decommissioning Insights 2016).
Industry member's organisation Decom North Sea - in collaboration with the UK Oil & Gas Authority, development agency Scottish Enterprise and representatives from a cross section of its member companies - has developed a web-based information portal to capture tools which have proven to add value while promoting advocacy in capturing good practices and lessons learned from the execution of decommissioning projects.
Known as the Late Life Planning Portal (L2P2), the system was launched in 2016 and is likely to become the sole repository of information on the decommissioning of offshore oil and gas facilities, whilst helping to increase knowledge and learning for the industry and contribute to an overall increase in efficiency and reduction in the cost of decommissioning.
An Innovative Regional Approach to the Analysis of Hurricane Impact on Offshore Platforms
Authors: Dubois R. , Cuny J. , Kervella Y. 
Published: April 2017

Abstract
Hurricanes are one of the biggest threats to offshore platform integrity and personnel security in the Gulf of Mexico. In hurricane-dominated regions, history of extreme events at a determined location, like an offshore platform, are often too scarce for a direct Extreme Value Analysis (EVA). Extreme Value Analysis being essential for structural design, it is necessary to explore new methodologies.
The spatial method presented in this article is based on the Regional Frequency Analysis (RFA), adapted to hurricane-generated sea states. The goal is to increase the size of the sample of extreme events considered for a given location, to ensure a more reliable view of the distribution of very extreme events. For a concrete application, a hindcast dataset of significant wave height over the Gulf of Mexico is decomposed into homogeneous regions where distinct locations show similar hurricane impacts. The identification of these homogeneous regions is performed by applying the Ward hierarchical clustering method on peaks of significant wave heights generated by hurricanes.
Five homogeneous regions are identified and described. It is then possible to trade space for time: we thus build samples of extreme events for each of the homogeneous regions, hence gathering a larger number of events than if we had only considered hurricanes which traveled above one given location. A parametric distribution is then used to describe the distribution of extreme events inside each homogeneous region.
Extreme value analysis at a given location is then computed by transposing the corresponding regional distribution of extreme events. This methodology allows to reduce significantly the confidence interval width around the significant wave height extreme values estimate, especially for the 100 and 1000-year return values.
The methodology presented is quite an innovation as it had never been applied before to a dataset of sea states resulting from hurricane activity. The results are very valuable to obtain better estimate of potential extreme wave height due to hurricanes, hence increasing the confidence in offshore platforms structural design and the overall security. Moreover, this methodology can be applied to other regions of the world impacted by very extreme events, and to other kind of spatial data, such as winds, currents, or storm surge.
Case Study of a Customized Solution for Intervention Operations to Increase Well Production
Authors: Olstad Delaney Michael , Canny Steven A 
Published: April 2017

Abstract
Three wells on an aged platform required extensive intervention operations due to several downhole issues. This paper will review the life cycle of the project and focus on the efficiencies of the customized system which was used to increase production of the wells.
Due to several challenges and limitations associated with the platform, traditional methods were neither operationally practical nor financially viable. New technology in the form of a fit-for-purpose system was utilized to safely and effectively complete all necessary procedures. The system, which includes a pulling unit, provided the foundation to support multiple resources and offered a complete integrated solution. The modular design of the pulling unit and the efficient operational capabilities allowed for operations to be conducted within the parameters of the platform.
Because the platform was in 73 ft of water, the operator first considered using a rig for the operation, but eventually reconsidered based on overall project costs and space limitations. Furthermore, there were production operations ongoing which, if halted, would result in a financial loss. A rigless, crane-based program was not an option because extensive fishing was needed and required high pulling forces. When a casing hanger became stuck, the design of the pulling unit facilitated a seamless switch from supporting the downhole operations with the hydraulic mast to pulling with the integrated casing jacks. The ability to customize the pulling unit enabled safe and efficient operations to be completed and resulted in a 300% production level increase.
With platforms and wells have varying characteristics, the operational equipment spread needs to be customizable to each project's parameters and be able to provide a full range of services. This paper will cover how the pulling unit challenges the traditional methods of rigless intervention to provide cost-effective solutions that help to significantly reduce high operating costs.
Underwater Precast Reinforced Concrete Silo For Oil Drilling and Production Applications
Authors: Mahmoud Mostafa H 
Published: April 2017

Abstract
Proposed is a precast reinforced concrete multi-cell circular silo for deep underwater oil drilling and production applications. Drilling takes place from the bottom of the silo using modified land drilling equipment mounted on the silo foundation. The proposed silo evolved in response to the Deepwater Horizon oil spill which flowed for three months in 2010 in the Gulf of Mexico. On July 15, 2010, the leak was stopped by capping the gushing wellhead after it had released about 4.9 million barrels of crude oil. Provisional patent application No. 61366544 was filed on July 22, 2010. United States Patent No.: US 8,684,630 B2 was issued on April 1, 2014.
The silo is embedded an appropriate distance into the seabed to ensure: a) weight, ballast and buoyancy result in acceptable bearing into the seabed and b) lateral loads due to wind and water action on the silo are adequately transmitted to the seabed. If required, steel piles and/or steel anchors secured into the seabed are provided to supplement embedment.
The silo is constructed from multi cell precast concrete segments fabricated at a plant with access to water. The segments are transported one-by-one to final location and assembled vertically down segment-by-segment starting with the foundation followed by the wall. Construction does not require the use of a dry dock or scuba diving work.
The assembled silo has sufficient buoyancy to remain afloat throughout the offshore assembly process. Production of the precast segments is scheduled to permit completion of the silo between two hurricane seasons.
The blowout and spillage risks associated with the proposed silo are significantly lower than the blowout and spillage risks associated with current systems capable of drilling for oil and gas at such water depths. The oil leak containment capacity of the silo is an added advantage.