A stiffened plate configuration is described in FIG. In order to properly dimension the water-entrapment plate stiffeners, the various hydrodynamic effects taking place on the plate must be properly accounted for; these consist of the following: inertia of the fluid surrounding the water-entrapment plate cause a force opposing the acceleration of the platform, particularly in the vertical direction; radiated waves generated by the platform as it moves result in energy being removed from the platform, incident waves interact with the platform hull causing forces, and viscous effects, predominantly due to the shedding of vortices from the plate edges also result in transfer of energy from the platform to the fluid. Topsides on these platforms must normally be installed offshore using heavy lift vessels.
- Large and small scale marine dynamics, astronomical tides and other environmental noise
- Trastorno somatomorfo sin especificación (F45.9)
- Sientes un dolor tolerable que es perceptible, pero no abrumador
- Hacer ejercicio físico y estiramientos
- Adaptación a las estaciones
Column-stabilized platforms offer significant advantages over other platform types. Other technological solutions provided to the flow assurance problem for extended tie-back include electrically heated flowline, which may be heated either continuously or before start-up. Offshore facilities include but are not restricted to any combination of the following equipment: a power generator to provide electricity to subsea facilities located beneath the platform on the seafloor, hydraulic motors to provide hydraulic power to a subsea wellhead or manifold, antennas and other communication equipment to exchange information with a host platform, a helideck, chemical storage and distribution systems, overnight accommodations for maintenance personnel, a crane or gantry to move equipment on the deck, a winch and A frame to perform workover on the wellhead, pumps or compressors to boost pressure in the tie-back flowline. Semi-submersible platforms, also referred to as column-stabilized platforms were initially designed to perform drilling activities offshore. A minimum offshore platform could therefore be used to perform operations currently conducted on much larger platforms.
Dolor Espalda Al Respirar
For example, Tension Leg Platforms (TLP’s) are anchored to the seabed using vertical steel pipes, called tendons, which provide a large stiffness in the vertical direction. Large radial stiffeners 702, extending from the columns 701 toward the plate outer edges are required to support the plate. 7 with girders 704 supported by the radial stiffeners 702, and stringers 705 supported by the girders 404. These structural members support the steel panels forming the water-entrapment plate. These beams may also provide buoyancy, such as semi-submersible platform pontoons, in order to reduce the draft of the platform when it is towed to its installation site. After completion and pre-commissioning, it can be floated out to sea and towed to its installation site where the mooring system has been pre-installed. The dynamics of offshore platforms can often be modeled using the relatively simple concept of harmonic oscillators, wherein the harmonic exciting force is provided by the oscillating wave force, the mass of the system is comprised of the platform mass as well as its added-mass, which is the amount of water entrained with the platform, the stiffness comes from hydrostatic effects, or changes in buoyancy with the motion of the platform, and damping comes from radiated waves or viscous effects.
Dolor Neuropático Que Es
Large beams 702 connecting two columns also provide support to the water entrapment plate, as well as rigidity to the overall structure. The plate must be supported by structural members in order to withstand extreme wave loading as well as fatigue damage due to the large number of wave cycles it is subjected to. Large beams 103 are connected to the columns at both ends providing rigidity to the platform.
The radial distance can be adjusted to control the natural roll and pitch period.
Serious limitations are expected with longer subsea tie-back, such as plugging of the line due to a decrease in pressure and temperature along the flowline. Similarly, equipment such as subsea pumps may be required to assist flow assurance over the tie-back length. Similarly, pitch and roll natural periods depend on the platform inertia, its added-moment of inertia, which is the rotational equivalent of added-mass, and the platform metacentric height, GM. Dolor de espalda y malestar general . The radial distance can be adjusted to control the natural roll and pitch period. As semi-submersible platform payload requirements are reduced and the platform get smaller, in order to keep the natural period in heave away from the wave spectrum, the column cross-sectional area may be reduced, which results in a reduction in the vertical stiffness, however this also results in a reduction of static stability. In order to develop smaller size or marginal fields, the weight of required process equipment is reduced, however existing platform concept cannot be easily scaled down because their motion performance tends to degrade considerably with smaller sizes.
Mini-TLP’s are smaller versions of TLP, but are typically not stable before they are connected to their tethers, and therefore the installation process is very complex, often requiring installation of Temporary Stability Modules as disclosed by Huang, U.S. The cost of such umbilical is typically very large, and economics of a subsea tie-back is often threatened by the excessive umbilical cost for tie-back distances greater than 20 miles. This could further extend the distance over which hydrocarbon can be transported allowing them in cases to reach the shore directly for further processing. Such chemicals can be transported from the host platform to the subsea wellhead in an umbilical, and can be injected into the flowline at the wellhead. The finite-element model requires discretization of the hull into small elements on which the beam or plate theory is applied.