[Posted on January 18, 2016 by Bill Stewart]
6 Ways Hydrodynamic Analysis Benefits the Off-Shore Oil Industry
As oil platforms move further and further off-shore in search of new and richer oil deposits, the challenges of finding and exploiting these new reserves become increasingly complex. There are many hydrodynamic forces at work both at water’s surface and beneath it, and without a thorough understanding of how these forces will affect equipment like oil platforms, a platform’s moorings, risers and pipelines, the consequences could be disastrous.
Hydrodynamic analysis helps to avoid rig downtime, tragic accidents, loss of life and environmental disasters by modeling and analyzing the forces that are at work on these components, so that the designs can be improved and strengthened to withstand the effects. It is also useful during the investigation of prior incidents to determine how the failure was caused and determine ways to avoid such incidents in the future.
Here are a few of the ways hydrodynamic analysis benefits the off-shore oil industry:
#1 Improved Platform Design
An off-shore oil platform is constantly subjected to ocean currents, tidal forces, wave action and both horizontal and vertical motion. The constant movement of water around structural components creates friction and areas of both high and low pressure that can start to fatigue vulnerable surfaces and contribute to corrosion at the water’s surface. As these components weaken, they can contribute to dangerous accidents or cause serious structural failures.
By using hydrodynamic analysis, the forces at work on the platform’s structure can be modeled and the design of the platform can be altered to make it stronger, more stable and longer-lasting. It can also help to reduce the maintenance requirements of the platform and lead to lower operational costs, while improving the overall safety of the working environment for the rig’s personnel.
#2 Improved Platform Moorings
For floating platforms or semi-submersible platforms, strong moorings are especially important to keep the platform stable and in the proper position. They must be strong enough to resist the action of the waves, moving the platform both vertically and horizontally, and they must also resist the current below the surface and along the turbulent sea floor. A failure of the moorings could lead to production disruptions and high repair costs, or it could lead to more serious problems.
With hydrodynamic analysis, the design of the moorings can be evaluated and improved to make sure that they can withstand the hydrodynamic forces and pressures that will exacted upon them. Different types of moorings will have completely different performance characteristics, and the analysis can help determine what types of anchors should be used in a particular area or situation, such as suction piles, drag embedment anchors or vertical load anchors, as well as the type of mooring line, such as chain, wire or synthetic materials. The analysis can also be used improve the designs of the fasteners connecting the mooring lines to the anchors, which will be subjected to extremely turbulent forces near the sea floor.
#3 Better Mooring Field Designs
Keeping supply vessels and oil tankers secure during the loading and unloading process is vital to the safety of both the platform and the ships. Any problems in the design of the mooring field could lead to dangerous ship movements that can cause injuries, property damage or environmental damage.
Using hydrodynamic analysis, the effects of tidal forces, ocean currents and wave action on both the ships and their moorings can be evaluated. By taking those calculations into account during the construction of the mooring field, the moorings can be properly placed to avoid dangerous encounters between ships and the platform or other vessels, and they can be placed in positions that will provide the most stability for loading and unloading operations.
#4 Better Riser Design
One of an oil platform’s most critical components is the riser, which connects the oil well to the platform and extracts the oil and gas from the deposit. Like other components, the riser is subjected to extreme forces and pressures, and must be able to withstand both lateral and vertical movement, as well as its own buoyancy. A riser failure can lead to environmental damages, injuries, or even more severe incidents, such as explosions.
By using hydrodynamic analysis, the rig operator can determine which type of riser and components should be used in a particular situation, such as flexible risers or rigid. The analysis can also help to design better components that will withstand higher forces and pressures.
#5 Precise Pipelaying Operations
Undersea pipes are subjected to extreme pressures, as well as the forces of the ocean currents, tidal forces and wave action. Pipes that are laid improperly or that are not designed to withstand the forces at play can fail, leading to environmental damage, production problems and expensive repair costs.
By employing hydrodynamic analysis, the pipes and fasteners can be analyzed and the designs improved to better withstand the forces and pressures present at such depths. It can also help to determine where the pipe should be placed to avoid the most extreme forces, and help the ships laying the pipes to do their jobs more effectively and efficiently. Done correctly, this should help to reduce the costs of laying pipe and improve its long-term durability.
#6 Improved Accident Investigations
Though accidents are rare in the off-shore drilling industry, compared to the number of active platforms, they still happen, and when they do, there can be serious injuries, environmental damage or even deaths. Additionally, when an accident happens, it halts production and can be very expensive for the platform operator and its partners.
Hydrodynamic analysis can help to determine how an accident occurred, and how it can be prevented in the future, by determining which components, if any, failed due to hydrodynamic forces. It can also be used to determine who is responsible for the incident, so that the proper measures can be taken.
Hydrodynamic analysis can be a crucial tool in the off-shore oil industry, and by using it to help in all phases of the platform construction and production processes, it can reduce maintenance costs and increase the overall safety of an oil platform.