bluuebunny/crossref_metadata_2025_split huggingface dataset:
Method for Driving Multiplexed Downhole Control Systems
Authors: Garcia Elias , El Mallawany Ibrahim 
Published: April 2016

The paper presents a method for driving multiplexed downhole control systems employed as part of an intelligent completion, and provides a comprehensive analysis of the data collected as well as conclusions and results of the presented methodology. The content presented in this paper is based upon theoretical, design, and field data obtained at different stages of a product's development lifecycle.
This paper identifies a specific application where charlieplexing is used to control downhole intelligent completion systems. Charlieplexing allows the selective engagement of solenoid valves at great lengths of distance with a minimum number of electronic components. When paired with existing hydraulic systems, charlieplexing allows selective channeling and remote operation of hydraulic fluid to interval control valves in a well. Protection of the system's electrical conductors is provided through a hydraulic fluid-filled tubing encased conductor (TEC), which increases the overall reliability and longevity of the entire system. In addition, the paper details the components that make up the system and the associated testing to validate the theory presented.
Using a charlieplexing methodology for the development of a downhole control system proved to be an effective way to engage up to 12 solenoid operated valves with the use of a fluid-filled TEC. This methodology has been proven through component reliability testing, system integration testing, and field testing. The charlieplexing methodology is different from other methodologies used in existing downhole control systems. Charlieplexing facilitates the use of passive electrical components to achieve selective control of solenoid operated valves. Because of its inherent architecture, the charlieplexing methodology does not require a communication protocol to selectively engage components, thereby minimizing the total amount of components in the system. Ultimately, this component reduction makes charlieplexing inherently more reliable as it has fewer failure points. Test data is presented to support this conclusion.
This paper introduces the idea of using charlieplexing as a means for driving downhole control systems when paired with downhole intelligent completions equipment. The paper also highlights the use of a nonconductive, hydraulic fluid-filled TEC to prevent wellbore fluid ingress.
Collaboration with Client: Industry's First Open- Head, Full Rotating High-Torque Bucking Unit Enables Makeup of Tubulars on Pipe Deck
Authors: Hulke Markus , Habetz Jeff 
Published: April 2016

Abstract
The prevailing drive to develop innovative solutions to reduce rig time and associated costs, coupled with enhancing safety and optimizing operational efficiency, prompted a major Gulf of Mexico operator to request a customized solution to allow make/break of drillpipe triples and casing doubles on its space-restricted deepwater production installation. Specifically, the operator sought a sustainable solution that would reduce operational costs by minimizing the online running of drill pipe, casing and tubing, while also reducing logistical hurdles and rig-floor hazards.
This paper describes the collaborative initiative that resulted in the engineering of a purpose-built pipe deck, which drove the development and deployment of the industry's first open-head bucking unit and bespoke pipe transfer system designed to enable fingertip make-up and breakout of drill pipe triples and doubles of casing and tubing. At the onset, a number of challenges had to be addressed to meet the operator's objective to vertically integrate the bucking and hands-free pipe transport system into the rig, which comprised a single-activity derrick with limited rack back capabilities. The authors will discuss the cradle-to-grave design process, which featured a cantilevered pipe bridge off of the rig floor to house the new bucking unit and pipe transfer system. Furthermore, owing to challenging well designs with increased risk of differential pipe sticking, the paper discusses the complementary design of positioning systems that deliver record vertical lift and horizontal tong movement of 13 ft (4m).
The development of the hands-free bucking unit and integrated pipe transport system clearly illustrates the intrinsic economic value of multi-party collaboration in creating operational efficiencies to reduce pipe process time, minimize or eliminate non-productive time (NPT), and deliver repetitive and predictive outcomes.
Application of an Advanced Data Analytics Methodology to Predict Hydrocarbon Recovery Factor Variance Between Early Phases of Appraisal and Post-Sanction in Gulf of Mexico Deep Offshore Assets
Authors: Gupta S. , Saputelli L. A. , Verde A. , Vivas J. A. , Narahara G. M. 
Published: April 2016

Abstract
Estimated Ultimate Recovery (EUR) is the expected amount of hydrocarbons that can ultimately be produced from a reservoir or group of reservoirs (oilfield) given certain subsurface characteristics and technologies. Usually, the EUR is estimated at different phases during the lifecycle of an E&P asset for a continuous economic assessment. Reduction in uncertainity in EUR estimation due to acquisition and analysis of data during early phases of exploration and appraisal would enable effective decision making process during later phases of development and production. Being able to predict EUR effectively early on in the field lifecycle would improve project viability and enable higher quality investment decisions during latter phases. In this study, EUR variance (?EUR) is computed between the EUR at pre-sanction and the EUR at post-sanction after first oil production. EUR variance is frequently overestimated as several reservoir parameters are unknown or less certain during appraisal phase. This paper presents a novel data-driven methodology to accurately determine ?EUR using known EUR at appraisal phase and data associated to oilfield characteristics, complexity and definition level. The methodology employs multi-variate statistical techniques and optimization procedure to construct a robust EUR estimation model and to identify key drivers that impact ?EUR. The analytical methodology was successfully validated and tested using real data from over 50 large operating assets of the Deepwater Gulf of Mexico (GOM) oilfields. Numerical case studies show the methodology was able to satisfactorily predict ?EUR and potential project train-wrecks with 73 and 85 percent of accuracy, respectively, as well as to identify, rank, and classify those key parameters responsible for both under- and over-estimating the EUR. The proposed model creates opportunities to reduce "appraisal gaps" between pre-sanction and post-sanction EUR and improve the field development planning process in a cost-effective manner. This data-driven methodology has immense potential in deepwater oilfields and other hydrocarbon plays to improve field appraisal and development strategy and also assess other risks in hydrocarbon management.
Europa Umbilical Retermination
Authors: Levar Jason , Seah Han Hsien 
Published: April 2016

Abstract
The Europa Chemical Injection (CI) umbilical was installed at the Mars platform in 1999. Over the past 16 years, many of the umbilical tubes were taken out-of-service due to leaks in the topside termination assembly. The umbilical was reterminated from the Mars platform during July and August of 2015. As a result, 6 out-of-service tubes were restored and the life and functionality of the umbilical was extended. In addition to the operational gains, the effort provided significant savings by mitigating the need for a replacement umbilical and simplifying a future abandonment operation. This is believed to be the industry's first ever topside retermination of an in service, steel tube umbilical.
The success of this offshore operation is significant to Shell and the greater operations community due to anticipated maintenance of aging, steel tube umbilicals like the Europa umbilical. Shell has several other umbilicals which were manufactured and installed in this same time period which may benefit learnings from this activity. It is believed based on engagement with the Europa operating partners that the learnings from this operation may also benefit other deepwater operators.
This first-of-its-kind operation established a best practice procedure to conduct a retermination of an aging umbilical from the platform. A new friction/squeeze clamp design was developed and qualified to 3 times the design load. The allowable squeeze limit of the umbilical was well above the calculated and recommended values. A unique chemical displacement strategy was utilized to partially displace the umbilical to accommodate cutting and welding activities. This strategy utilized S-traps along the umbilical route to prevent chemical backflow which drastically reduced the displaced volume of chemical.
In the current economic climate, operators are looking for ways to prolong the life of their aging assets. This operation is an example of a unique, cost-effective solution to maturing brownfield assets.
Subsea Separation - Advanced Subsea Processing with Linear Pipe Separators
Authors: Prescott N. , Mantha A. , Kundu T. , Swenson J. 
Published: April 2016

Abstract
Production fluid typically leaves a well in multiple phases, including: oil, gas, water, and solids. It is necessary to separate these components in order to recover the oil and gas, treat the water, dispose of sand, etc. In the past decade there has been a trend to move processing equipment to the seabed. As offshore production continues to be developed in deeper water, it is imperative to develop separator technology that will be designed for the hydrostatic forces and large amounts of produced water that is expected to occur over time.
This paper explores two novel subsea linear pipe designs that allow subsea processing to be accomplished more cost effectively than existing technologies. The process undertaken for designing the two novel subsea linear pipe separation technologies: (gas-liquid) and (gas-liquid-solids) is described. To validate the efficiency and effectiveness of these two systems, a Computational Fluid Dynamics (CFD) analysis and cost analysis have been performed for each separator to provide both a realistic view of the actual separation efficiency of the systems, as well as comparative cost efficiency to existing technology in use today. Separators utilizing the pipe classification can be made lighter and cheaper when compared to existing subsea separation modules. In addition, they can be fabricated out of standard pipe sizes, thus cutting costs due to high availability and ease of fabrication. These factors are made even more attractive when modularized for ease of installation and field expansion.
Applications of the process and design of these special separators are discussed along with their potential advantages in offshore deepwater seabed based developments. With continued research and testing, the gas-liquid and gas-liquid-solid linear pipe separator designs have the potential to reshape the subsea separation industry.
A Paradigm Shift in Subsea Technology Research and Development
Authors: Anikpo Afam 
Published: April 2016

Abstract
Crude oil prices are in the doldrums, major capital projects are being rolled back due to reduced commercial viability and the overall health of the oil and gas industry seems to be hanging in the balance. Contrary to popular notion, the timing could not be better to review the less than convincing industry approach towards research and development of new technologies.
This paper presents a review of the technology research and development process in the oil and gas industry, with emphasis on subsea technologies. It also investigates the approach towards technology advancements in other technology-driven industries such as Aerospace, Telecommunications and IT. It juxtaposes the findings of this investigation with the oil and gas industry. It discusses the key drivers, benefits, risks and overall strategies associated with technology development and adoption across these industries.
The investigation reveals a fundamental flaw in the approach to technology research and development in the oil and gas industry. The lessons learned from drawing parallels with other technology-driven industries are used to propose a new approach to subsea technology research and development.
Realtime Monitoring, Using All Available Data, Plays A Vital Role In Successful Drilling Operations
Authors: Moore Cory , Doyle Eamonn , Jewula Karol , Karda Lukasz , Sheehy Tim , O'Connor Stephen , Djordjevic (Obie) Obren 
Published: April 2016

Abstract
In order to mitigate predrill uncertainties and provide the well team with the best information to drill proactively, monitoring of borehole operations in realtime is vital on wells drilled today. Realtime monitoring (Pore Pressure while Drilling – PPwD) gives the team the best chance to drill the well safely and efficiently to planned targets. Recent proposals by the United Sates Bureau of Safety and Environmental Enforcement indicate realtime monitoring might soon be mandatory on many offshore US wells. One particularly important aspect of realtime monitoring is pore pressure and fracture gradient estimation and prediction.
Most analysis of drilling data, such as petrophysical, drilling parameters, gas and geology, relies solely on depth-based data, which of course are only available while drilling ahead, i.e. wellbore depth is increasing. The depth-based analysis model is relatively low resolution with data points at 0.5 foot or 0.2 meter intervals. If calibrated correctly the models are valuable and accurate, providing the well team with useful insight about present and possible future events.
However, there are many operations during the drilling of a well that do not generate depth-based data, such as pipe connections, circulating off-bottom, wiper trips, flow-checks etc., that instead, generate time-based data. When analyzed, such data provide invaluable information to permit further calibration of the models. Realtime pore pressure models that only contain depth-based information are potentially flawed because the many calibration points that occur while the bit is off bottom are not captured/recorded in the model. Building a time-based model in parallel to the depth-based model allows for a far more robust picture of downhole conditions.
This paper will use real examples from the Gulf of Mexico to explain the importance and benefits of constructing a time-based model that will be used alongside the depth-based model. It will also demonstrate how discrepancies between depth-based models and time-based models can arise.
The result of using all available data, in both depth and time domain, is a more robust, integrated model on which to base the pore pressure estimation and prediction and ensure the well team gets the best possible information.
Dissolvable Metal vs. Dissolvable Plastic in Downhole Hydraulic Fracturing Applications
Authors: Walton Zachary , Fripp Michael , Merron Matt 
Published: April 2016

Multiple dissolvable materials are becoming available in the energy industry. While dissolvable plastics have their applications, a dissolvable metal has distinct advantages over a dissolvable plastic for hydraulic fracturing.
Multiple tests were performed to compare the characteristics of dissolvable metals and dissolvable plastics. The two product families that were explored were dissolvable frac balls and dissolvable frac plugs. For direct comparison, frac balls and frac plugs were constructed using a dissolvable metal and dissolvable plastic. For both dissolvable frac balls, the materials were tested for impact resistance. For both dissolvable frac plugs, the materials were pressure tested.
The dissolvable metal frac ball provided higher impact resistance than the dissolvable plastic frac ball. The dissolvable metal frac ball survived impact at 19 bbl/min on ball-to-seat interference as small as 0.035 in. When the same test was performed using a dissolvable plastic ball, the ball shattered and passed through the seat. The seat overlap needed to be increased to 0.125 in. before the dissolvable plastic ball was able to consistently survive impact against the seat. For the frac plugs, the dissolvable plastic was unable to be used as a bottom slip because of the anchoring loads generated while the plug sealed against differential pressure. The dissolvable metal was able to anchor these loads when used as the material for the bottom slip. For a dissolvable plastic mandrel to survive the setting loads, it had to be set in compression. The dissolvable metal mandrel had no issue being set in tension, allowing for the operational setting procedures to be unchanged. Dissolvable plastic also required the inner diameter of the frac plug to be much smaller.
Using dissolvable metal instead of dissolvable plastic reduces design requirements for converting non-dissolvable downhole tools to dissolvable ones. Dissolvable metal provides an increased impact resistance, has no issues being set under tension, and allows for using smaller ball-to-seat overlaps, all of which provide more flexibility for use in industry applications.
An Evaluation of Subsea Gas Scrubbing at Extreme Pressures
Authors: Setekleiv Eddie , Anfray Jérôme , Boireau Clément , Gyllenhammar Emil , Kolbu Jostein 
Published: April 2016

Abstract
High pressure separation may be needed in subsea compression systems for long distance subsea tie-backs if a dry gas compressor specification is to be met. This paper investigates the performance of gas scrubbers at high pressure (&gt;200 bar). Axial flow cyclones are the last stage of gas polishing within a conventional gas scrubber, and will determine the gas quality. Gas/liquid separation at high pressure is known to be challenging as density difference and surface tension is reduced between hydrocarbon phases. Re-entrainment of liquid droplets in axial flow cyclones is considered a limiting factor for efficient separation at high pressure. Using re-entrainment as a design criterion alone will effectively reduce the gas velocity through the cyclones. Reducing gas velocity to limit re-entrainment can result in poor separation due to a reduction in centrifugal force, causing more droplets to escape the cyclone. In this paper, existing models from literature for re-entrainment and cyclone cut size are extrapolated to field conditions of a notional deep offshore gas field. The goal is to map performance and explore limitations of a conventional scrubber design with axial flow cyclones for subsea high pressure separation. The extensive use of modelling and design rules effectively identifies issues and limitations of existing design approaches for gas scrubbing when moving to higher pressures.
Qualification of New Design of Flexible Pipe Against Singing: Testing at Multiple Scales
Authors: Golliard J. , Lunde K. , Vijlbrief O. 
Published: April 2016

Abstract
Flexible pipes for production of oil and gas typically present a corrugated inner surface. This has been identified as the cause of "singing risers": Flow-Induced Pulsations due to the interaction of sound waves with the shear layers at the small cavities present at each of the multiple corrugations. The new flexible technology discussed in this paper, called K-carcass, is made of shaped wires and presents a very different bore profile compared to other folded-strip flexibles. In a preliminary study based on small scale testing, it was showed that the new inner profile geometry of this technology was more robust for Flow-Induced Pulsations compared to the folded strip carcass. A qualification program was initiated to address the different risks associated with the introduction of a new pipe technology. A primary goals of this qualification program was to extend the results of the preliminary study to the actual carcass at field conditions (natural gas at production pressure).
In this paper, the method followed to qualify the singing behavior of the new flexible technology as installed in the field at operational conditions is considered. The testing program and the scaling approach used to extrapolate results obtained at different scales towards full-scale pipes are described. The program includes a combination of small-scale and large-scale testing. The small scale singing testing consists of blow-through tests of 2" and 3" pipes with corrugated inner bore with air at low pressures on a setup with well-defined acoustic boundary conditions. The large-scale singing testing consists of similar tests on 3" and 5" pipes with natural gas at close-to-operational pressures. These tests are completed with full-scale tests, where a reference riser and a prototype of new-technology riser are tested with natural gas at high pressure. The combination of scales and gas properties at which the tests are done, and the continuity between the different tests conditions, will allow the validation of theoretical and empirical scaling laws used in the qualification of the new riser in operational conditions.
The blow-through tests with the prototype pipe with the new K-carcass tested with natural gas at close-to-operational pressure did not show any singing. In contrast, the reference pipe (with folded-strip carcass) started singing even at low velocities. The test results can be extended to an allowable production envelope for a pipe in field conditions.
Such a qualification of new technology has to rely on existing prediction tools. As these tools were developed to analyze the singing behavior of the existing technologies, this combined theoretical and experimental approach reduces the risks associated with the introduction of a new technology.