Model Test With a Vertical Pipe to Elevate Cold Sea Water

2018 ◽  
Author(s):  
C. C. O. Trigo ◽  
C. K. Morooka
Keyword(s):  
Numerical Simulations ◽  
Oil And Gas ◽  
Sea Water ◽  
Optical Measurement ◽  
Small Diameter ◽  
Water Tank ◽  
Vertical Pipe ◽  
Pipe Length ◽  
Pipe Model ◽  
Sea Bottom

Vertical pipes are extensively applied on offshore petroleum operations, such as subsea wellbore drilling, wellbore re-entry, installations of equipment on the sea bottom, hydrocarbon production as the conductor for oil and gas from the wellhead at the sea bottom, among other applications. Recent oil and gas field discoveries in ultra deepwater brought an increase of the amount of produced and processed petroleum onboard of floating production system. Consequently, the process plant demands more cooling capacity. One of the alternatives is to elevate cold sea water. The present study aims to improve the understanding of the behavior of a vertical pipe forced to move at its upper end in a water tank. Displacements along the pipe length are measured, and main features of the behavior of the pipe model with its bottom end free are observed. Motions imposed at the vertical pipe intent to represent motions of the surface from the floating platform or ship, due to waves, currents and wind. Pipe model vibrations are analyzed, and results allowed improvements for the input in numerical model simulations to Orcaflex software. Developments of the analysis procedure and evaluations of the experiment allow more reliable design of riser operations with its bottom end free in actual sea operations. In the present work, a physical model with a pipe of small diameter has been developed for the laboratory experiment, and an optical measurement system is used to measure the pipe model displacement in the water tank. Motions are imposed at the top termination by a mechanical device. Experiment is described in details and comparative analyses between experiment and numerical simulations were carried out. Results from numerical simulations as well as from the experiment brought important contributions for description and understanding of the vertical pipe behavior.

Dynamic Behaviour of a Free Hanging Vertical Pipe Forced to Oscillate at the Top

2020 ◽  
Author(s):  
L. P. A. Sales ◽  
C. C. O. Trigo ◽  
L. C. Sevillano ◽  
C. K. Morooka
Keyword(s):  
Laboratory Experiments ◽  
Dynamic Behaviour ◽  
Optical Measurement ◽  
Small Diameter ◽  
Vertical Pipe ◽  
Pipe Length ◽  
Pipe Model ◽  
Diameter Pipe ◽  
Out Of Plane ◽  
As Stress

Abstract Vertical pipe configuration happens in subsea well re-entry operations for wellbore drilling, subsea equipment installations, deepwater intake risers, among other scenarios, usually by hanging the marine riser at the top from a platform or ship. The simple operational configuration justifies its wide application; however, there are some drawbacks such as stress concentration, fatigue, among other issues. The purpose of this study is to contribute for the overcoming of those problems by improving the understanding of hanging risers through investigations of a vertical pipe forced to oscillate horizontally at the top. For this purpose, laboratory experiments with small diameter pipe model have been developed with oscillatory motions applied at the top termination through a mechanical device. Displacements over time and along the pipe length were measured by an optical measurement system. In the present study, a numerical scheme has been implemented for simulations to support evaluations of the experimental results. A vertical pipe response depends on several parameters, such as pipe overall length, frequency and amplitude of oscillation itself, among others. Due to existing relative velocity between the oscillating pipe and the water surrounding it, vortex shedding occurs along the pipe length which influences riser motion behaviour. The results from experiment and numerical simulations bring important insights for describing and understanding oscillatory vertical pipe behaviour, in the plane and the out of plane of the forced top oscillation. The obtained results provide a further step toward the modelling of Vortex-Induced Vibration (VIV) in marine risers, aiming to contribute to relevant technological advancements.

Numerical and Experimental Analysis of the Tensile and Bending Behaviour of CFRP Cables

2017 ◽  
Vol 25 (9) ◽  
pp. 643-650
Author(s):  
Eduardo Antonio Wink de Menezes ◽  
Laís Vasconcelos da Silva ◽  
Carlos Alberto Cimini Junior ◽  
Felipe Ferreira Luz ◽  
Sandro Campos Amico
Keyword(s):  
Analytical Model ◽  
Oil And Gas ◽  
Steel Wire ◽  
Small Diameter ◽  
Oil And Gas Industry ◽  
Small Radius ◽  
Tensile Behaviour ◽  
Specific Strength ◽  
Numerical Predictions ◽  
Bending Behaviour

Due to their high fatigue life, specific strength and specific stiffness in comparison with steel, carbon-fibre reinforced polymer (CFRP) cables have attracted the infrastructure industry interest in recent years, primarily for use as structural tendons. Particularly the oil and gas industry showed interest for application in offshore platform anchorage systems, because of their exceptional corrosion and creep/relaxation behaviour. In such applications, the cables need to be tensioned in service and to be bent around relatively small-diameter spools for transportation and maintenance. Therefore, their tensile and bending behaviour is a subject of great concern. The aim of this work was to perform a test program on 1 × 19 CFRP cables in two different situations: tensile loading and four-point bending loading. Finite element models were developed to simulate both conditions, including frictional contact between the cable wires. A simplified analytical model was also used to predict the cable behaviour in tension. Numerical predictions were compared to experimental data showing relatively good accuracy, unlike the verified analytical model. CFRP cables presented outstanding tensile behaviour, but bending over small radius spools could not reach the performance of steel wire ropes. Furthermore, simulation could only fairly predict bending below strains of μ1,000 μe for the external rods, beyond which the cable presented highly non-linear behaviour that could not be simulated by the numerical model.

Finnmark Platform Composite Tectono-Sedimentary Element, Barents Sea

2021 ◽  
pp. M57-2020-20
Author(s):  
E. Henriksen ◽  
D. Ktenas ◽  
J. K. Nielsen
Keyword(s):  
High Frequency ◽  
Oil And Gas ◽  
Barents Sea ◽  
Upper Jurassic ◽  
Source Rocks ◽  
Basement Rocks ◽  
Sea Bottom ◽  
Middle Carboniferous ◽  
Uralian Orogen ◽  
Glacial Periods

AbstractThe Finnmark Platform Composite Tectono-Sedimentary Element (CTSE), located in the southern Barents Sea, is a northward-dipping monoclinal structural unit. It covers most of the southern Norwegian Barents Sea where it borders the Norwegian Mainland. Except for the different age of basement, the CTSE extends eastwards into the Kola Monocline on the Russian part of the Barents Sea.The general water depth varies between 200-350 m, and the sea bottom is influenced by Plio-Pleistocene glaciations. A high frequency of scour marks and deposition of moraine materials exists on the platform areas. Successively older strata sub-crop below the Upper Regional Unconformity (URU, which was) formed by several glacial periods.Basement rocks of Neoproterozoic age are heavily affected by the Caledonian Orogeny, and previously by the Timanide tectonic compression in the easternmost part of the Finnmark Platform CTSE.Depth to crystalline basement varies considerably and is estimated to be from 4-5 to 10 km. Following the Caledonian orogenesis, the Finnmark Platform was affected by Lower to Middle Carboniferous rifting, sediment input from the Uralian Orogen in the east, the Upper Jurassic / Lower Cretaceous rift phase and the Late Plio-Pleistocene isostatic uplift.A total of 8 exploration wells drilled different targets on the platform. Two minor discoveries have been made proving presence of both oil and gas and potential sandstone reservoirs of good quality identified in the Visean, Induan, Anisian and Carnian intervals. In addition, thick sequences of Perm-Carboniferous carbonates and spiculitic chert are proven in the eastern Platform area. The deep reservoirs are believed to be charged from Paleozoic sources. A western extension of the Domanik source rocks well documented in the Timan-Pechora Basin may exist towards the eastern part of the Finnmark Platform. In the westernmost part, charge from juxtaposed down-faulted basins may be possible.

Subsea Cable Stability on Rocky Seabeds: Comparison of Field Observations Against Conventional and Novel Design Methods

2018 ◽  
Author(s):  
Terry Griffiths ◽  
Scott Draper ◽  
Liang Cheng ◽  
Feifei Tong ◽  
Antonino Fogliani ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Power Transmission ◽  
Small Diameter ◽  
Oil And Gas Industry ◽  
Operational Reliability ◽  
Design Methods ◽  
Gas Industry ◽  
Integrity Management ◽  
Tidal Stream ◽  
Almost All

As offshore renewable energy projects progress from concept demonstration to commercial-scale developments there is a need for improved approaches beyond conventional cable engineering design methods that have evolved from larger diameter pipelines for the oil and gas industry. New approaches are needed to capture the relevant physics for small diameter cables on rocky seabeds to reduce the costs and risks of power transmission and increase operational reliability. This paper reports on subsea cables that MeyGen installed for Phase 1a of the Pentland Firth Inner Sound tidal stream energy project. These cables are located on rocky seabeds in an area where severe metocean conditions occur. ROV field observation of these cables shows them to be stable on the seabed with little or no movement occurring over almost all of the cable routes, despite conventional engineering methods predicting significant dynamic movement. We cite recent research undertaken by the University of Western Australia (UWA) to more accurately assess the hydrodynamic forces and geotechnical interaction of cables on rocky seabeds. We quantify the conformity between the cables and the undulating rocky seabed, and the distributions of cable-seabed contact and spanning via simulations of the centimetric-scale seabed bathymetry. This analysis leads to calculated profiles of lift, drag and seabed friction along the cable, which show that all of these load and reaction components are modelled in an over-conservative way by conventional pipeline engineering techniques. Overall, our analysis highlights that current cable stability design can be unnecessarily conservative on rocky seabeds. Our work foreshadows a new design approach that offers more efficient cable design to reduce project capex and enhance through-life integrity management.

scholarly journals Potential Use of Water Associated with Conventional Oil Production and Sea Water as Base Fluids for Hydraulic Fracturing Operations: Effect of Water Chemistry on Crosslinking and Breaking Behaviors of Guar Gum-Based Fracturing Fluid Formulations

2016 ◽  
Vol 6 (1) ◽  
pp. 31 ◽  
Author(s):  
Dayanand Saini ◽  
Timea Mezei
Keyword(s):  
Los Angeles ◽  
Hydraulic Fracturing ◽  
Water Chemistry ◽  
Fresh Water ◽  
Oil And Gas ◽  
Guar Gum ◽  
Sea Water ◽  
Oil Production ◽  
Fracturing Fluid ◽  
Conventional Oil

 Even though water consumption per hydraulic fracturing (or fracturing) job is relatively low; nearly all of the fresh water used for fracturing in California is in the regions of high water stress such as San Jouquin and Los Angeles Basins. However, water availability should not be a concern as huge volumes of water are being produced along with oil and gas from conventional formations (i.e. associated water) in the Kern County of California, a region where most of the fracturing activities take place. This associated water can potentially be used for preparing fracturing fluids in stimulating the unconventional formations. The present study reports on the relevant investigation done in this area of interest.The results suggest that associated water chemistry has limited effect on the viscosity of cross-linked formulations. However, guar gum concentration was found to affect the breaking behaviors of cross-linked fracturing fluid formulations. The new type of commercially available biodegradable breaker was found to be effective in breaking the tested cross-linked formulations at elevated temperature which was as high as 85°C (185°F). Both crosslinking and breaking behaviors of fracturing fluid formulations evaluated in this study were found comparable to the behaviors of commonly used cross-linked formulation (guar gum + 2% potassium chloride). These results suggest that both the associated water (i.e. water resulting from regional conventional oil production activites) and sea water (offshore oil fields) could serve as alternative sources of base fluid for use in fracturing jobs without putting significant burden on precious regional fresh water resources.

Visualization and Numerical Simulations of Condensing Flow in Small Diameter Channels

2018 ◽  
Vol 40 (9-10) ◽  
pp. 802-817 ◽  
Author(s):  
Paolo Toninelli ◽  
Stefano Bortolin ◽  
Marco Azzolin ◽  
Davide Del Col
Keyword(s):  
Numerical Simulations ◽  
Small Diameter

Sea bottom characteristics and geochemistry of oil and gas seeps in the Gulf of Mexico

2021 ◽  
pp. 1-60
Author(s):  
John Decker ◽  
Philip Teas ◽  
Daniel Orange ◽  
Bernie B. Bernard
Keyword(s):  
Gulf Of Mexico ◽  
Gas Hydrates ◽  
Oil And Gas ◽  
Geochemical Analysis ◽  
Mud Volcanoes ◽  
Sea Bottom ◽  
High Backscatter ◽  
Oil Extract ◽  
Brine Pools ◽  
Gas Seeps

From 2015 to 2018, TGS conducted a comprehensive multiclient oil and gas seep hunting survey in the Gulf of Mexico. The basis for identifying seeps on the sea bottom was a high-resolution Multi-Beam Echo Sounder survey, mapping approximately 880,000 km2 of the sea bottom deeper than 750 m water depth, at a bathymetric resolution of 15 m and a backscatter resolution of 5 m. We have identified more than 5000 potential oil and/or gas seeps, and of those, we cored approximately 1500 for hydrocarbon geochemical analysis. The sea bottom features best related to hydrocarbon seepage in the GoM are high backscatter circular features with or without bathymetric expression, high backscatter features with “flow” appearance, mud volcanoes, pock marks, brine pools, “popcorn” texture, faults, and anticlinal crests. We also tracked gas plumes in the water column back to the sea bottom to provide an additional criterion for hydrocarbon seepage. Cores from sea bottom targets recovered liquid oil, tar, and gas hydrates. Oil extract and gas analyses of samples from most target types produced values substantially higher than background in oil and gas.

Short-term cell volume regulation in Mytilus californianus gill.

1994 ◽  
Vol 194 (1) ◽  
pp. 47-68
Author(s):  
A L Silva ◽  
S H Wright
Keyword(s):  
Cell Volume ◽  
Sea Water ◽  
Optical Measurement ◽  
Regulatory Volume Decrease ◽  
Cell Volume Regulation ◽  
Acute Exposure ◽  
Mytilus Californianus ◽  
K Channel ◽  
Short Term

Long-term acclimation of Mytilus californianus to 60% artificial sea water (585 mosmol l-1; ASW) led to a 30-40% decrease in the taurine (53.5-36.9 mumol g-1 wet mass) and betaine (44.8-26.2 mumol g-1 wet mass) content of gill tissue, compared with that of control animals held in 100% ASW (980 mosmol l-1). The K+ content of gills did not change following long-term acclimation to reduced salinity. In contrast, losses of all three solutes during a brief (60 min) exposure to 60% ASW were less than or equal to 15%. Nevertheless, the swelling of gill cells that occurred after acute exposure to 60% ASW was followed by a return towards the control volume. Direct optical measurement of single gill filaments confirmed that, during an acute exposure to reduced salinity, ciliated lateral cells increased in cell height (volume) and then underwent a regulatory volume decrease (RVD) with a half-time of approximately 10 min. This short-term RVD was completely inhibited by exposure to 1 mmol l-1 quinidine, a K+ channel blocker, but only when the drug was applied to the basolateral aspect of the gill epithelium. Application of 1 mumol l-1 valinomycin relieved the inhibition by quinidine of the gill RVD. However, addition of valinomycin did not accelerate the rate of RVD observed in the absence of quinidine. These results indicate that long-term acclimation of Mytilus californianus gill in dilute sea water involves primarily losses of taurine and betaine, whereas short-term regulation of cell volume may involve an electrically conductive loss of intracellular K+ and a counter ion.

scholarly journals Influence of the Thermometer Inertia on the Quality of Temperature Control in a Hot Liquid Tank Heated with Electric Energy

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 4039
Author(s):  
Dawid Taler ◽  
Tomasz Sobota ◽  
Magdalena Jaremkiewicz ◽  
Jan Taler
Keyword(s):  
Water Temperature ◽  
Time Constant ◽  
Temperature Control ◽  
Complex Structure ◽  
Small Diameter ◽  
Hot Water ◽  
Temperature Control System ◽  
Water Tank ◽  
Water Storage Tank

This paper presents the medium temperature monitoring system based on digital proportional–integral–derivative (PID) control. For industrial thermometers with a complex structure used for measuring the temperature of the fluid under high pressure, the accuracy of the first-order model is inadequate. A second-order differential equation was applied to describe a dynamic response of a temperature sensor placed in a heavy thermowell (industrial thermometer). The quality of the water temperature control system in the tank was assessed when measuring the water temperature with a jacketed thermocouple and a thermometer in an industrial casing. A thermometer of a new design with a small time constant was also used to measure temperature. The quality of water temperature control in the hot water storage tank was evaluated using a classic industrial thermometer and a new design thermometer. In both cases, there was a K-type sheathed thermocouple inside the thermowell. Reductions in the time constant of the new thermometer are achieved by means of a steel casing with a small diameter hole inside which the thermocouple is precisely fitted. The time constants of the thermometers were determined experimentally with a jump in water temperature. A digital controller was designed to maintain the preset temperature in an electrically heated hot water tank. The function of the regulator was to adjust the power of the electrical heater to maintain a constant temperature of the liquid in the tank.

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