bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flexible Fiber-reinforced Pipe for 10,000-foot Water Depths: Performance Assessments and Future Challenges
Authors: Jha V. , Dodds N. , Finch D. , Latto J. , Karabelas G. , Anderson T.A. , Baehmann P. , Vermilyea M.E. 
Published: June 2014

Abstract
The primary aim of the present composite development program is to enhance access to deepwater fields in the Gulf of Mexico, Brazil, and West Africa. To accomplish that goal, composite materials are being incorporated in unbonded flexible pipelines to lower mass and enhance the overall system performance to expand the operational design envelope. In addition, the use of composite materials will allow a significant improvement in pipe operating pressure (&gt;70 MPa), pipe operating temperature (&gt;125C) and due to increased CO2 and H2S resistance, will improve sour service performance and lifespan.
Composite materials are well known for their low density and high specific strength, stiffness and fatigue performance. These properties are desirable and will certainly enhance pipe performance, but the overall performance of the pipe during all stages of manufacture and deployment must be considered, as well as a conservative approach to introducing these new materials. Some of the key factors that need to be assessed are material failure modes under varied pipe loadings, dynamic interactions and exposure to severe oil field environments. There are several individual standards, specifications and joint industry projects (JIPs) focused on composite pipes that address some of these issues, but there is also a general lack of consensus with regard to testing standards and understanding of the long-term performance. As flexible pipe suppliers, the industry must aim to provide performance assessments and address all key challenges to allow the flexible pipe industry to build confidence in the new and enabling composite pipe technologies.
In a previous paper, we presented design concepts and a toolbox approach to construct different composite pipe solutions to meet all the aforementioned performance parameters. The present paper selectively highlights important failure modes and design considerations, demonstrates an understanding of behavior in the matrix and fiber phases, and addresses concerns related to the chemical performance of composite materials. The present paper also highlights and addresses some of the concerns of composite pipes and focuses on areas for future development and testing. These results will help support the selection and standardization of analysis tools and testing methods across the industry. Bespoke testing capabilities to address the relevant failure mechanisms and installation strategies for composite pipes will also be discussed.
Steel Catenary Riser Design for Cylindrical FPSO Application in Ultra-Deep GoM
Authors: Vidic-Perunovic J. , Guo X. S. , Wang L. , Hopen F. , Head W. J. 
Published: June 2014

Abstract
The exploitation of Gulf of Mexico (GoM) Lower Tertiary reservoirs is confronted with many physical, technical and economic challenges, including ultra-deep water depth, remote locations, complex fluids and high reservoir pressure, harsh met-ocean conditions, and increased capital expenditure, etc. To address these challenges different floater and riser concepts have been studied by the industry. This paper documents a study on an FPSO concept with the Sevan-type cylindrical hull (CFPSO) in combination with Steel Catenary Risers (SCRs). In comparison to the ship-shaped FPSO combined with Free Standing Hybrid Riser (FSHR) solution, the CFPSO has inherently more favorable motion characteristics and is therefore more SCR friendly. In addition, the hull was designed with a central moonpool for hanging off SCRs and therefore coupling from roll/pitch motions was minimized. The CFPSO and SCR design is based on a hypothetical field in ultra-deepwater GoM Lower Tertiary play with HPHT reservoirs and central GoM met-ocean conditions. Based on preliminary motion data of the CFPSO, feasibility of SCR has been numerically evaluated in terms of strength and fatigue performances. Results based on first order wave response analysis show that strength and fatigue criteria were both satisfied in critical riser locations, indicating feasibility of the concept in this stage of the study.
The paper represents one sub-scope of the RPSEA study "Low Cost Flexible Production System for Remote Ultra-Deepwater Gulf of Mexico Field Development.", Project No. 10121–4404–03.
Impact of Water Cut on Asphaltene Deposition Tendency
Authors: Wang J. , Fan T. , Buckley J.S. , Creek J.L. 
Published: June 2014

Abstract
A systematic lab study was conducted to investigate the impact of water on asphaltene deposition tendency, with emphasis on percent water cut and ion composition. Two crude oils from Gulf of Mexico with different properties were applied as probe oils to study asphaltene deposition using a capillary deposition flowloop. Distilled (DI) water and a synthetic brine with 6.5% NaCl salinity were used to create water-in-oil emulsions to study the impact of water on asphaltene deposition. For one oil sample, it was observed that adding as few as 2 vol% DI water to the oil/n-heptane mixture could cause as much as 56% reduction on deposition rate. When DI water was replaced by the synthetic brine, the reduction in deposition rate decreased. However, when the synthetic brine also contained ferric ion (Fe3+) or aluminium ion (Al3+), the deposition rate was restored back to the same or an even higher level as the base case without water. ICP analysis revealed that deposits collected from tests with ferric ion or aluminium ion also contains significant amount of those two ions, plus remarkable increases on other divalent ions including Ni and V. In the second oil, adding 10–20% synthetic brine also reduced deposition rate 10–25%. With only 10 ppm ferric ion in the brine, the deposition rate for the second oil was largely restored back to the original level without water.
Status of Equation of State Project at the NETL
Authors: Gamwo I.K. , Burgess W.A. , Morreale B. D. , Soong Y. , Bamgbade B. A. , McHugh M. A. , Baled H. O. , Enick R. M. , Wu Y. , Tapriyal D. 
Published: June 2014

Abstract
We describe a collaborative effort to accelerate the development of Equation of State (EoS) models to predict density and viscosity of crude oils at temperatures up to 533 K and pressures up to 276 MPa. These conditions are consistent with reservoirs encountered in ultra-deep formations such as in the Gulf of Mexico. The collaboration is organized by the U.S. Department of Energy-National Energy Technology Laboratory and two universities (University of Pittsburgh and Virginia Commonwealth University). This is being done by conducting well-defined validation experiments and by developing cubic and SAFT-based mathematical expressions for density and viscosity. The net result of this effort will be a suite of validated equations of state for crude oil at high temperature and high pressure conditions, and the widespread usage of these equations in reservoir simulators. Such reservoir models are critical not only to assess the magnitude of oil spills associated with failures in the wells or of production equipment but also to develop the appropriate response strategies should such accidents occur.
Flow Assurance Issues Related to Flexible Riser and Pipeline System Configuration
Authors: Yu Leyuan , Mohammad Saif , Button Scott , Li Mingxiu 
Published: June 2014

Abstract
Flexible riser and pipeline systems have been proposed as a promising solution for offshore oil and gas production systems in various harsh and challenging marine environments. They have many advantages compared with traditional rigid riser and pipeline systems, including: relatively low axial bending stiffness; ability to spool on a reel for easy transport and faster installation; and suitability for various floating systems.
Flexible riser and pipeline systems typically have buoyancy modules to produce a lazy wave or similar configuration in the riser to decouple the floating vessel motions from the touchdown point. However, the buoyancy modules may move or even drag the riser in the horizontal direction, which may cause the riser shape to change or the riser bottom to move on the seabed. The riser shape/configuration may change, even slightly, with the movement of buoyancy modules or flexible riser, resulting in potentially significant changes in flow assurance design issues related to slugging and system blowdown.
Case studies were carried out using transient multiphase simulation software, as reported in this paper, to investigate the slugging issues impacted by slight variations in the riser configuration in flexible pipeline/riser systems, including slight uphill and downhill riser base configurations. These small changes in the riser shape/configuration can also cause significant differences in the resulting residual pressures in the subsea pipeline and riser after blowing down the system.
The results from this paper suggest that the riser shape/configuration in flexible pipe systems has a significant impact on flow assurance concerns, especially the impact of slugging and blowdown residual pressures related to hydrate prevention and mitigation. Consequently, the sensitivity of riser shape/configuration in flexible riser and pipeline systems should be considered in early design phases to understand the impact on key flow assurance strategies.
Improving Overhead and Reducing Time Consumption on P&A Operations with E-line, Explosion-free, Mechanical Cutter Tool
Authors: Krüger Christian , Faraoun Abderrahmane , Eikeland Tommy 
Published: June 2014

Abstract
With regards to most interventions there is a major interest in saving time on high cost items like daily rig charges, as well as improving the safety of the operations. Traditionally, pipe cutting operations are conducted using a rig to keep the tubing in tension in order to cut the pipes with explosives or other means. This paper will describe several plug and abandonment (P&A) intervention operations conducted on subsea wells in the North Sea without the use of explosives.
The overall objectives of the operation were to P&A and sidetrack two wells. After setting two 5 1/2? bridge plugs on the first well, the 5 1/2? tubing 23# 13% Cr was cut with a novel, e-line, mechanical cutter tool under compression (estimated at 1.5 to 2 tons), in one attempt, in two hours and 41 minutes. This enabled the rig to go directly to the pulling of the tubing instead of being involved in the release of the packer, saving time and overhead.
On the second well, two 5 1/2? bridge plugs had also been set prior to cutting a 5 1/2? tubing 23# 13% Cr S110, under compression, using standard cutting pads. The cut was successful on the first attempt. The actual cutting time lasted four hours and 40 minutes. In both cases, pre P&A work was conducted via Riserless Light Well intervention(RLWI) with the cutter run from the rig, but the cutter itself could also have been run on a RLWI operation with a more economical vessel than a drilling rig.
This paper will describe the planning process and operations, incl. the non-explosive design of the mechanical cutter that uses a rotating head to remove pipe incrementally, without creating shavings. Furthermore, the paper will discuss the lessons learned from these operations as well as future potential of this tool used as a rigless method.
Road to Offshore Gas Production Test - from Mallik to Nankai Trough
Authors: Saeki Tatsuo 
Published: June 2014

Abstract
The world's first offshore gas production test from methane hydrate deposits was conducted in March 2013, at the test site located on the margin of Daini Atsumi Knoll, off the coasts of Atsumi and Shima peninsulas, in the easten Nankai Trough, of Japan. Approximately 120, 000 cubic meters of methane gas was produced in 6 days using the depressurization technique.
The test was a significant advance in Japan's national program to construct the technical base for future commertial methane hydrate resource development. A series of researches for more than 10 years, including two times of onshore production tests in Mallik field and explorations in eastern Nankai Trough, were required to reach the test.
This report reviews Japan's research history for methane hydrates.
The Design Ice Island for Impact Against an Offshore Structure
Authors: Dunwoody A.B. 
Published: June 2014

ABSTRACT
A method is presented by which an ice island may be selected for preliminary design of an offshore structure. The method involves:Estimation of the risk of an ice island impact.Determination of the distribution of kinetic energy amongst impacting ice islands.Selection of a design kinetic energy based on the maximum risk of failure which would be acceptable.Selection of a design ice island. The design ice island is chosen to be the ice island which is most likely to hit the offshore structure with the design kinetic energy.
The ice island statistics are reviewed and analysed using the above selection method to define a design ice island.

INTRODUCTION
Offshore structures have been bull t over the past several years for oil exploration in the Canadian and American Beaufort Seas. It is anticipated that larger, longer-term offshore structures will soon be built for oil production. Amongst the hazards which will have to be considered during the design of an oil production structure which have not been considered for exploration islands are ice islands. Ice islands are the largest individual ice features which could threaten an offshore structure in the Beaufort Sea. Originating from the ice shelves along the northern coast of Ellesmere Island, ice islands occasionally break-off and become incorporated in the permanent polar pack. Their Subsequent motions are controlled by winds, ocean currents, pack ice pressures and coriolis acceleration. The trend in the resulting motion is the familiar Beaufort Gyre. Approximately once every ten years, an ice island under the influence of the Gyre will pass through the Beaufort Sea. Eventually each island entering the Gyre will escape or disintegrate.
To date, all ice islands which have been observed to pass through the Canadian Beaufort Sea have passed far north of the exploration acreage. However, an ice island passing through the Beaufort Sea in the future could drift further south through the exploration acreage. If an ice island entered the exploration acreage during the open water season, its great mass coupled with the potentially high drift speeds possible in open water or loose pack would endow the ice island with tremendous kinetic energy. Any offshore structure which was struck would have to dissipate that kinetic energy safely or be destroyed.
In anticipation of designing a production structure, two questions must be answered with regard to ice island impacts during the summer. Is the risk of an ice island hitting an offshore structure great enough that the offshore structure should be designed to withstand such a hit? If the answer to the first question is yes, then what are the dimensions and other characteristics of the ice island against which the offshore structure should be designed. The simplest answer to those questions is to design the offshore structure to withstand an impact by the largest ice island imaginable. Although certainly conservative, that answer may be impractical or at least very expensive.
Random Analysis of a Riser for a Floating Production System (FPS) in a Northern North Sea Environment
Authors: Westin L.H. 
Published: June 2014

ABSTRACT
The effects of the instantaneous position of the free wave surface and the non-linear wave loading on the riser response in the top part of the riser are determined by numerical time domain simulations. For the small diameter riser analysed in the paper it is shown that both these effects can have a significant influence on short term extreme peak predictions in severe environmental conditions.

INTRODUCTION
One option for the development of an offshore oil field in 305 m (1000 ft) water depth is a Floating Production System (FPS). Such a system comprising a purpose built floating production unit and a multibore production riser linking the subsea manifold to the floater is schematically shown in Fig. 1.
It is recognised that an accurate prediction of the dynamic behaviour of the riser is a key item in the development of such a system. An extensive analysis of this multibore riser has consequently been performed.
The riser is composed of 12 × 3.5" conduits arranged in a square array. The twelve conduits are split into four bundles of three conduits each. The square array is maintained by spacers that prevent inter-bundle collisions.
Selected extracts of observations made during the analysis are presented in this paper. The attention is focussed on the effects of the free wave surface and the non-linear wave loading in extreme peak predictions of riser response in the top part of the riser in severe environmental conditions in the northern North Sea

SIMULATION PROCEDURE
In order to achieve the objective of making accurate predictions of dynamic riser response it is recognised that computer codes for riser analysis must be able to simulate the random behaviour of the sea and the associated riser response. The results from this random analysis must be treated in a probabilistic manner (5, 6).
The analysis reported in this paper is made in the time-domain. A unidirectional random sea is realised with a Pierson-Moskowitz spectrum and linear wave theory (4). Correlated time series of wave particle kinematics and riser top motion are realised by discretising this input spectrum into a finite number of randomly phased components. It has been proved that the wave surface elevation, the riser top motion and the wave kinematics below mean sea level (MSL) are accurately simulated as random Gaussian processes in this manner. However, the linear wave theory breaks down above MSL. An empirical technique known as 'stretching' is used to map the wave kinematics as calculated below MSL up to the instantaneous position of the free wave surface on the riser, Fig. 1.
For the horizontal hydrodynamic forcing function the relative velocity form of the Morison equation is invoked.
In its disconnected and 'hung-off' mode the riser is vertically fixed to the floater. Due to the random floater heave motion (h) the tension in the riser will also be a random variable.
Two effects will contribute to the tension fluctuations provided that longitudinal vibrations are not in the frequency of predominant heave motion.
Lysophosphatidic Acid Receptor 5 Inhibits B Cell Antigen Receptor Signaling and Antibody Response
Authors: Hu Jiancheng , Oda Shannon K. , Shotts Kristin , Donovan Erin E. , Strauch Pamela , Pujanauski Lindsey M. , Victorino Francisco , Al-Shami Amin , Fujiwara Yuko , Tigyi Gabor , Oravecz Tamas , Pelanda Roberta , Torres Raul M. 
Published: June 2014

Abstract
Lysophospholipids have emerged as biologically important chemoattractants capable of directing lymphocyte development, trafficking, and localization. Lysophosphatidic acid (LPA) is a major lysophospholipid found systemically, and its levels are elevated in certain pathological settings, such as cancer and infections. In this study, we demonstrate that BCR signal transduction by mature murine B cells is inhibited upon LPA engagement of the LPA5 (GPR92) receptor via a Gα12/13-Arhgef1 pathway. The inhibition of BCR signaling by LPA5 manifests by impaired intracellular calcium store release and most likely by interfering with inositol 1,4,5-triphosphate receptor activity. We further show that LPA5 also limits Ag-specific induction of CD69 and CD86 expression and that LPA5-deficient B cells display enhanced Ab responses. Thus, these data show that LPA5 negatively regulates BCR signaling, B cell activation, and immune response. Our findings extend the influence of lysophospholipids on immune function and suggest that alterations in LPA levels likely influence adaptive humoral immunity.
Cutting Edge: Parathyroid Hormone Facilitates Macrophage Efferocytosis in Bone Marrow via Proresolving Mediators Resolvin D1 and Resolvin D2
Authors: McCauley Laurie K. , Dalli Jesmond , Koh Amy J. , Chiang Nan , Serhan Charles N. 
Published: June 2014

Abstract
Bone marrow macrophages stimulate skeletal wound repair and osteoblastic bone formation by poorly defined mechanisms. Specialized proresolving mediators of inflammation drive macrophage efferocytosis (phagocytosis of apoptotic cells) and resolution, but little is known regarding this process in the bone marrow. In this study, metabololipidomic profiling via liquid chromatography mass spectrometry revealed higher levels of specialized proresolving mediators in the bone marrow relative to the spleen. The endocrine and bone anabolic agent parathyroid hormone increased specialized proresolving mediator levels, including resolvins (Rvs), in bone marrow. Human and murine primary macrophages efferocytosed apoptotic osteoblasts in vitro, and RvD1 and RvD2 (10 pM–10 nM) enhanced this process. These findings support a unique profile of specialized lipid mediators in bone marrow that contribute to a feedback system for resolution of inflammation and maintenance of skeletal homeostasis.
IL-1β Promotes the Differentiation of Polyfunctional Human CCR6+CXCR3+ Th1/17 Cells That Are Specific for Pathogenic and Commensal Microbes
Authors: Duhen Thomas , Campbell Daniel J. 
Published: June 2014

Abstract
In humans, Th1/17 cells, identified by coexpression of the chemokine receptors CCR6 and CXCR3, are proposed to be highly pathogenic in several autoimmune disorders due in part to their expression of the proinflammatory cytokines IL-17, IFN-γ, and GM-CSF. However, their developmental requirements, relationship with “classic” Th17 and Th1 cells and physiological role in normal immune responses are not well understood. In this study, we examined CCR6+CXCR3+ Th1/17 cells from healthy individuals and found that ex vivo these cells produced the effector cytokines IL-17, IL-22, and IFN-γ in all possible combinations and were highly responsive to both IL-12 and IL-23. Moreover, although the Ag specificity of CCR6+CXCR3+ Th1/17 cells showed substantial overlap with that of Th1 and Th17 cells, this population was enriched in cells recognizing certain extracellular bacteria and expressing the intestinal homing receptor integrin β7. Finally, we identified IL-1β as a key cytokine that renders Th17 cells sensitive to IL-12, and both cytokines together potently induced the differentiation of cells that produce IL-17, IFN-γ, and GM-CSF. Therefore, interfering with IL-1β and IL-12 signaling in Th17 cells during inflammation may be a promising therapeutic approach to reduce their differentiation into “pathogenic” CCR6+CXCR3+ Th1/17 cells in patients with autoimmune diseases.