bluuebunny/crossref_metadata_2025_split huggingface dataset:
Low Frequency Seismic Acquisition Innovations Approaching One Hertz
Authors: Meier Mark , Lewallen Kyle , Otero Jose , Heiney Steve , Murray Tom 
Published: April 2015

Abstract
Expanding the low frequency seismic band promises to improve subsurface imaging and inversion and reduce risks in exploration and production of hydrocarbons. Modern seismic acquisition technologies measure several octaves of earth response. New acquisition technologies can provide several more octaves of low frequencies.
The industry has made substantial effort towards modifying existing acquisition technologies to capture additional low frequencies without compromising the higher frequencies. This approach relies on existing acquisition technology concepts. In our work, we set out to identify those specific traits found in existing acquisition technologies that are obstacles to step-change improvements in low frequency bandwidth. We then sought to devise new technology concepts that dispense with those traits. For example; the low frequency ghost notch is a major obstacle for marine seismic sources, land and marine sources suffer orders-of-magnitude losses in force output at low frequencies, and measurements from motion sensors in multicomponent streamers are problematic at low frequencies due to streamer dynamics. We have devised alternative technology concepts for seismic sources and multicomponent streamers that address these challenges; namely, the marine dipole seismic source, the counter-rotating eccentric mass actuator, and the pressure gradient transducer.
We are presently in research and development stages of these new technologies and are obtaining encouraging results. Our theoretical work predicts technical feasibility, and our experimental studies have confirmed tested aspects of the theory. We conclude these technologies have potential to extend the low frequency seismic band at least two octaves beyond modern capabilities. More experimental work remains to be completed, but based on the evidence gathered so far, we are persuaded to begin consideration of the next stages in development and commercialization.
Reassessment of Subsea processing Technology to Maximize Recovery on Offshore Marginal Field Developments
Authors: Ohanyere I. J. , Abili N 
Published: April 2015

Abstract

Objective/Scope
International and National oil companies have in their portfolios deep offshore marginal fields. Development of these fields is usually constrained by the CAPEX, OPEX, flow assurance and safety issues, which increases with maturity of the field. Subsea processing technology (SPT) is not only pivotal for unlocking such fields, but offers a novel approach that meets the challenges of developing offshore marginal fields. The present paper explores conceptual development from some of the most innovative solutions and performance analysis of the optimal SPT with field case studies demonstrated.

Methods, Procedures, Process
The paper provides a reassessment of the different SPTs available in the market as well as the limitations of such technologies. Conceptual development is carried out using a 3-step approach involving the Quality function deployment (QFD) and its tools, the Voice of customer (VOC) and Quality Matrix or House of Quality (HOQ) that analyzes and compares the capabilities of various SPTs to overcome the techno-economic challenges of marginal fields. Revalidation of results from the QFD process is done using Analytical Hierarchal process (AHP) and its pair wise comparison process, leading to the optimal innovative SPT for marginal field development. Field case analysis of this novel solution is applied to fields in the North Sea and Gulf of Guinea over an eight years period.

Results, Observations, and Conclusions
The present paper validates the effectiveness of SPT in tackling marginal field techno-economic challenges such as large CAPEX and OPEX, slugging, low recovery rate, remoteness of location amongst others issues. Its application in one of the fields led to increased projected revenue of up to $450,000,000 in recovery, as well as significant reduction in maintenance and work over costs. The analysis shows that SPT such as the deployment of Multiphase Pumps can be a game changer if effectively applied in marginal field development.

Novel/Additive Information
The paper explores the novel application of QFD and AHP to develop offshore marginal fields. These tools have been used effectively in so many fortune 500 companies, where they have led to a significant reduction in cost as well as reduction in project implementation time. Proper application of the processes described in the present paper can serve as a better alternative over the traditional field conceptual development, to maximize recovery in offshore marginal fields.
Riserless Light Well Intervention Operations in Harsh Environment - A Case Study from West of Shetland
Authors: Løver Terje A. , Bjerkvik Oddbjørn 
Published: April 2015

The area West of Shetland (WoS) between the UK and Faroe Islands, also known as the Atlantic Frontier, is characterized by a harsh environment with strong currents, presenting significant challenges for offshore operations. Our experience in this area began for the first time in 2009, performing Riserless Light Well Intervention (RLWI) operations. This type of well intervention had never been performed in this area and the challenge showed to be far bigger than first anticipated.
This is the seventh season with RLWI operations West of Shetland, an environment which is known to be very challenging due to extreme ocean currents. The first season there were significant struggles with the difficult environmental conditions. Strong currents caused damages to both RLWI equipment and vessel, forcing the operation to be stopped. To be able to complete the operations a quick adaption to this demanding environment was needed. The organization managed to turn around quickly and do the needed modification to respond to the challenging environment, making it possible to complete the operations in this harsh environment. After a steep learning curve and 6 years operational experience in this area, the operations are now completed ahead of schedule.
This paper will discuss the challenges experienced performing RLWI operations West of Shetland. Damages to equipment caused by the harsh environment and the “battle” to overcome these challenges will be discussed.
Field Applications for Advanced Robotics
Authors: Nayar Hari D. 
Published: April 2015

Abstract
Applications of advanced robotics systems have grown over the past couple of decades in a wide range of industries. These include deployments in the space, military, manufacturing, mining, agriculture, emergency-response, oil and gas, transportation and many other sectors. Innovations in materials, sensors, actuators, mechanical design, computing hardware, software architectures, modeling and simulation, control algorithms, motion planning, machine perception, artificial intelligence and machine learning have all contributed to the highly capable and reliable robotics systems available today. At NASA's Jet Propulsion Laboratory (JPL), robots that integrate technologies from all these disciplines are being developed for a variety of space and terrestrial applications. This paper will give an overview of some of the state-of-the-art technologies being developed at JPL and describe potential applications for them in the oil and gas industry. Robotics skills and expertise at JPL are broadly categorized by discipline into the general areas of mechanical & electrical hardware development, modeling & simulation, mobility systems, manipulation & sampling systems, computer vision & perception, estimation & control, and operations. Through the life cycle of a robotics project, these skills are drawn on, usually with hardware, embedded systems and modeling and simulation development emphasized in the early stages and transitioning to advanced control, behavior and intelligence development at the later stages. Integration of these capabilities into robotics systems has resulted in a number of cutting-edge applications in planetary exploration, in-space servicing, surgery, ground, marine and aerial vehicles, and search & rescue. Areas in the offshore industry where these technologies could be applied include surveillance, inspection and maintenance of offshore surface and underwater facilities, automation of drilling, and production processes, safety and security monitoring and spill monitoring and cleanup. The benefits to be gained in developing robotics systems for oil and gas applications include reduced exposure of human operators to hazardous conditions, improved precision & reliability, and reduced cost. Current robotics technology is sufficiently mature for near-term applications in surveillance, inspection and maintenance operations for facilities and sub-sea systems. More sophisticated systems could be used in the future for challenging applications like autonomous well intervention, pipe inspection, and deepwater maintenance and repair. Potential oil and gas applications for surveillance and inspection of facilities, subsea infrastructure and pipelines are illustrated.
Evaluation of Commercially Available Virtual Flow Meters (VFMs)
Authors: Amin A. 
Published: April 2015

This report documents a project to improve subsea flow measurements to allow the flowrates of individual wells to be known more accurately. Because production revenues are determined from flowrates, improved flow measurement reduces the financial risk to stakeholders, including producers and the U.S. government. Improved measurement also helps to improve reservoir recovery. In this study, commercially available flow models were evaluated for their suitability as virtual flow meters (VFM).Virtual flow meters use input from sensors installed at various measurement points (nodes) in the wellbore, on the seabed and in surface facilities. The evaluation of this approach to flowrate metering is particularly meaningful in deepwater subsea applications to complement and backup physical measurements robustly and in a cost effective manner. The soft implementation of this modeling approach leverages already existing information from various measurement devices in the in the wellbore and subsea infrastructure.The study aimed at assessing the implementation and performance of commercially available VFM software packages using real production data from a subsea well equipped with a subsea multiphase flowmeter (MPFM). The study consisted of three evaluation rounds involving five commercial VFM products. The models were tuned incrementally using the subsea multiphase meter elemental computing parameters consisting of total mass flowrate, gas volume fraction (GVF), and water-liquid ratio (WLR). The results from a series of ‘blind’ tests were compared to actual flowrates with the objective to establish the sensitivity of the models' results to the measurement devices, the parameters used in the tuning, and measurement devices and fluids properties inconsistencies.Compared to other evaluations, the study is based on existing production data from a live well in which extensive data quality checks were necessary prior to sharing the data with VFM suppliers. Such effort led to consistent and conclusive results from at least three VFM packages that completed all three study rounds. The findings from the study using this data set confirm the robustness of VFM techniques in estimating production flowrates with adequate tuning. It was also established that VFM can be a cost effective and reliable backup measurement instrument to an ailing subsea multiphase meter where partial meter measurement and VFM can restore functionality to the combined flow measurement system.
A Major Offshore Trial of a Free-Standing Mid-Depth BOP Drilling Riser System
Authors: Guo Yongfeng , Ji Shaojun , Tang Changquan , Lim Frank , Zhang Hui , Ching Lishen 
Published: April 2015

Abstract
A major offshore trial of a mid-depth BOP drilling riser system was conducted in 2009 by COSL in 470m water depth of the South China Sea. The objective of the trial was to demonstrate the feasibility of using a shallow water drilling platform to drill in depths which would otherwise be beyond its reach. A free-standing tieback string supported by a buoyancy unit presented an ‘artificial seabed’ and wellhead at an elevation which the platform's existing drilling riser with its subsea BOP could connect to and drill through.
The trial mobilised a 3rd generation semi-submersible drilling platform Nanhai 5, its drilling riser and subsea BOP, a test tieback string, and a fully commissioned buoyancy unit. The full offshore transportation and installation sequences were executed for Nanhai 5 to successfully connect to a mock-up ‘real seabed’ wellhead via the afore-mentioned set-up.
The novel components in the system, particularly the tieback string and buoyancy unit, were instrumented and monitored to study their motion behaviour for correlation against analytical predictions.
In the present day ultra-deepwater drilling world, the interests for such a depth-extending system have revived, in the context of the fleet of modern 3000m-rated drilling platforms wanting to go beyond 3000m water depth. The lessons learnt from the COSL trial bear significant relevance for designing future systems.
This paper describes the trial, its design and planning, certain problems encountered and some recorded system behaviour.
True Downhole Measurement of Differential Pressure
Authors: Hall J.E. , Tiliakos N. , Brown J. , Worst T. , Foster R. B. 
Published: April 2015

Abstract
There is a need to accurately measure the flow rates of well fluids, in both drilling and production operations. While pairs of absolute pressure sensors could be used, a true differential pressure (DP) measurement is required for accurate downhole flow measurement, but has not previously been available. The goal of this work was to design, fabricate and test an HPHT (high-pressure, high temperature) DP sensor at borehole temperatures up to 500 Deg F and pressures up to 10,000 psi. An HPHT absolute P and a DP sensor were developed for subsea flowmeter use in the RPSEA – the Research Partnership to Secure Energy for America – project 07121-1301. However, the diameter of that P-DP sensor cell is too large for downhole applications which require a less than one-inch diameter cell. The 1301 design was modified using solids-modeling software and prototypes were fabricated. Because of the high common-mode pressure, electron-beam welding was required to join the DP cell components together and to the pressure flanges. The completed units were calibrated at ambient conditions and then sent to a certified metrology facility for testing at HPHT conditions.
Calibration of the DP cell showed perfect linearity and good overall accuracy. The maximum error at each of the extremes (500 Deg F and at 10,000 psi) was measured as 0.02% of upper-range limit, even without data processing to make this a "smart" DP transmitter. The cell's overpressure protection functioned to prevent damage to the MEMS DP chip at the extreme conditions. Care must be taken in the electron-beam welding step of the fabrication to prevent the sensor chip's temperature from exceeding its maximum rating. The development demonstrated the ability of the design to meet the requirements for a true HPHT DP sensor for downhole applications.
The measurement capability of a small diameter, true HPHT DP sensor will be of benefit in normal production flow measurement, but it could also be valuable in early detection of a well inflow event during drilling. Observing loss of well control as it is happening could mean the difference between a safe operation and one that is not. Additionally, the DP sensors could also be located at a fixed downhole location, at the sea floor, or at intermediate points (e.g. zones) in the well.
Anti-HS Layer for Flexible Pipe: Full Scale Flowline Qualification Tests
Authors: Chirat M. , Epsztein T. , Lefebvre X. , Minter P. Le 
Published: April 2015

Abstract
For more than 40 years, flexible pipes have been used for subsea oil and gas transportation. One of the main benefits of this technology is that, through an unbounded assembly of steel and polymer layers, the load bearing layers of the pipes are not in direct contact with the transported fluid and the corrosive components such as hydrogen sulphide (H2S).
However, over a long period of time, small quantities of gas, including H2S, are able to permeate through the polymer pressure sheath and reach the metallic structural layers. To avoid this, a new polymer layer able to completely prevent H2S from reaching the annulus has been developed. This layer is called the anti-H2S layer.
As part of the qualification program, an H2S exposure full scale test was performed. A flexible pipe structure with an anti-H2S layer was tested in harsh conditions, continuously exposed to gas containing methane mixed with 1.5% H2S and 5% CO2 at 200 bar (2902 psi) and 80°C (176°F) for 600 days. Several successful integrity tests were performed along the qualification program. After the H2S exposure test, the full scale prototype underwent a hydrostatic pressure test. Pipe dissection and laboratory material characterization were then performed to confirm the efficiency of the anti-H2S layer.
The positive result obtained in the long term H2S exposure full scale test and qualification program demonstrate the efficiency of the anti-H2S layer. The use of the anti-H2S layer concept creates new opportunities in terms of flexible pipe design, especially for ultra deep water and very sour fluid transportation.
Chain Out of Plane Bending (OPB) Joint Industry Project (JIP) Summary and Main Results
Authors: Rampi Lucile , Dewi Fata , Vargas Pedro 
Published: April 2015

Abstract
In 2002, several mooring chains of a deepwater offloading buoy failed prematurely within a very small time frame. These chains were designed according to conventional offshore fatigue assessment using API recommendations. With this first deepwater buoy application, a new mooring chain fatigue mechanism was discovered. High pretension levels combined with significant mooring chain motions caused interlink rotations that generated significant Out of Plane Bending (OPB) fatigue loading. Traditionally, interlink rotations are relatively harmless and generates low bending stresses in the chain links. The intimate mating contact that occurs during the proof loading and the high pretension of the more contemporary mooring designs have been identified as aggravating factors for this phenomenon.
A Joint Industry Project (JIP), gathering 28 different companies, was started in 2007 to better understand the OPB mooring chain fatigue mechanism and propose some mooring chain fatigue design recommendations.
This paper summarizes the various test programs that were implemented within the more than 6 years long project, including full scale fatigue tests on chains, a quasi static OPB stiffness measurement campaign, and tests on small samples addressing the environmental parameter influence on fatigue initiation and crack propagation stages.
The main output from the FEA scope of work, performed to support the experimental tests, will also be described.
Finally, the paper will address the major step that has been achieved regarding implementation of a standard practice in offshore industry using a multiaxial fatigue criterion to address OPB hotspots.
Critical HP/HT Flowline Design Challenges Associated With Deepwater Miocene GoM Fields
Authors: Gavem Tor , Kumar Amitabh , Panga Vijaykumar , Stratton Mike , Harry Jason J. 
Published: April 2015

Abstract
High Pressure / High Temperature (HP/HT) design of a flowline system has become a common design challenge as the quest to extract hydrocarbons has pushed the industry to exploit deeper reservoirs. In recent years, industry has classified systems over ~10,000 psi and over ~300°F as XHPHT (Extra HP/HT). As subsea technology continues to develop, it may not be farfetched to be soon considering UHPHT (Ultra HP/HT) flowline designs.
This paper addresses the key features and challenges of the HP/HT design as applied to the production flowlines of a deepwater Miocene GoM (Gulf of Mexico) field. The dual production flowlines are each ~10 miles long with SITP (Shut-In Tubing Pressure) of ~15000-psi and maximum design temperature of ~300°F (classified as XHPHT). HP/HT specific design challenges are associated with large expansion, global buckling, axial creep, and low-cycle fatigue, which are directly influenced by the flowline length. Even though the tie-back distance to the host is relatively long, the definition of "short" and "long" flowline/pipeline loses its significance due to distributed responses (both "Natural" and "Engineered") of system. Additionally, due to field-specific fluid properties, excessive pressure drops across the well perforation and / or the subsea choke can cause Joule-Thomson heating effects, which must be accounted for in design. This paper further discusses optimization of various design components in order to accommodate small variations in the input parameters (soil, operational transients, installation tolerances etc.) that are crucial with respect to global and local responses.
This case study uses mitigation techniques at pre-determined locations to address the design concerns such as large expansions, rogue (uncontrolled) buckles, axial creep ("walking"), and low-cycle fatigue. By exercising careful review of the iterative assessments and subsequent optimization of the system's overall design, a safe and reliable solution is achieved. HP/HT design philosophy for deepwater Miocene GOM fields form an integral part of design / implementation processes in the field development program and have significant influence on the overall subsea architecture, procurement and construction strategy, operating philosophy, and integrity management plan. Finally, the paper shows a comparison of numerical prediction and the data acquired from the field observations. The predicted system response is in good agreement with the field observations, thereby, validating the overall assessment/modeling approach and confirming the robustness of the system's response.