Results 221 to 230 of about 916,843 (300)

Lock-in Prediction Of Marine Risers And Tethers

Journal of Sound and Vibration, 1994
Abstract A model is presented to predict the cross-flow displacement of a deep water marine riser or tether (tendon) due to vortex-shedding in a vertically sheared flow. The displacement of each mode is determined by a balance between the energy fed into the structure over lock-in regions of the structure and the energy dissipated by the fluid ...
openaire   +1 more source

Active disturbance rejection adaptive fuzzy backstepping control of uncertain flexible marine riser system

Journal of Vibration and Control
In this paper, vibration control of a flexible marine riser with uncertain parameters subjected to distributed disturbance and boundary disturbance is studied.
Li Zhou, Guorong Wang, Min Wan
semanticscholar   +1 more source

An Analysis of Marine Risers For Deep Water

Journal of Petroleum Technology, 1973
A model is used to calculate this static and dynamic behavior of a marine riser supported from a floating vessel. Analysis examples demonstrate the consequences of extrapolating an existing riser design into deep water, and show that the dynamic behavior of the riser, caused primarily by vessel response to waves, is a significant design factor in all ...
openaire   +1 more source

Riser Recoil During Unscheduled Lower Marine Riser Package Disconnects

IADC/SPE Drilling Conference, 1998
Abstract In the event of a deep water emergency disconnection, the sudden release of the Lower Marine Riser Package (LMRP) connector can cause the riser string to reach destructive velocities and displacements. Impact between the outer barrel of the telescoping joint and the diverter housing must be avoided.
William Puccio, Reid Nuttall
openaire   +1 more source

FIRSTLING-DIGIMAR, a Pilot Scale Digital Twin of a Marine Riser for Field Use

Day 4 Thu, May 09, 2024
We developed and tested in real time FIRSTLING-DIGIMAR, a pilot scale digital twin of a marine riser driven by sparse field measurements. The FIRSTLING consists of hardware and software that includes a reduced order model developed through multi ...
E. Kharami, A. Mentzelopoulos, E. Prele, K. Shukla, Z. Wang, B. Bray, Q. Cao, A. Singh, D. Fan, T. Sapsis, M. Triantafyllou, G. Karniadakis   +11 more
semanticscholar   +1 more source

Stabilization of solutions of marine riser equations

Mathematical methods in the applied sciences
We study the problem of stabilization to zero stationary state of nonlinear fourth‐order wave equation with nonlinear damping term modelling dynamics of marine riser by feedback control terms that employ finitely many Fourier modes.
S. Ahmedov, V. Kalantarov, A. Namazov
semanticscholar   +1 more source

Development of an Instrumented Marine Riser Joint

Journal of Energy Resources Technology, 1982
A marine riser pup joint was instrumented to measure riser tension, bending moment, and mud temperature and pressure. The ground rules for the design, major design decisions, significant details, and calibration and testing are discussed.
J. L. Evans, D. A. Ganser, S. J. Williams   +2 more
openaire   +1 more source

Riser Modeling Scheme for a Load-Sharing Marine Drilling Riser

Volume 3: Pipeline and Riser Technology; CFD and VIV, 2007
Typical riser analysis for a marine drilling riser using the conventional composite modeling scheme will have only one line of elements mathematically representing riser pipe and auxiliary lines. The mass and weight of the riser system may be properly modeled. It is up to the analyst to include auxiliary lines’ stiffness, bending and/or axial. The rule
Roger Chang, Ed Fisher
openaire   +1 more source

Necessary Tension in Marine Risers

Revue de l'Institut Français du Pétrole, 1977
The tension governing transverse static and dynamic deflections in a riser is not the actual tension but the so-called « effective tension » The concept of effective tension and effective compression is thoroughly explained, and means for calculating effective forces are given. Numerical examples are worked out for risers whose length is between 152 m (
openaire   +1 more source

SUPERVISORY SWITCHED CONTROL OF MARINE RISERS

IFAC Proceedings Volumes, 2007
Abstract For a riser array in deep waters interference between individual risers exposed to strong ocean current and/or large TLP motions is of concern. The lateral deflections are likely to be large, and the risers may experience collision with fatigue or surface damage as a consequence.
Anne M. Rustad, Asgeir J. Sørensen, Carl M. Larsen   +2 more
openaire   +1 more source