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Anchor Analysis for Offshore Drilling

Stewart Technology Associates has a history of excellence that makes us the perfect candidates for your anchor analysis needs. We use only the best software and hardware to provide you with estimates and calculations, you know exactly what you need to do on site. We also offer information on cable dynamics, so you know what tools and equipment are necessary and what you can do to improve your drilling system’s effectiveness.

At STA, we use OrcaFlex by Orcina to provide accurate information and anchor analysis. Since 1986, we have worked with drillers around the world, from government agencies to oil companies. We assist in gathering information, analyzing data, and making improvements that allow these structures to work to the best of their abilities. We also work with our clients to provide information on the best ways to improve the site for the safety of their employees; together, we can improve the site’s output while protecting the interest of those working on site.

Anchor analysis for offshore drilling is vital for a number of reasons. Drilling in new areas means you need to know the anchors you’re using and what they can handle, as well as the lay of the land under the ocean. With anchor analysis by Stewart Technology Associates (STA), you can rely on the information you receive. Anchor analysis will help you overcome any challenges you face in your drilling ventures, and STA can offer you solutions that will work when put into practice. Whether you’re lead to needing new flexible risers or want to explore new piping options, STA can help you get the right tools for the job.

We look at a client’s operation as a whole. When we receive the results of your analysis, we use this information to tell you how you can improve the safety of workers and heighten your site’s productivity. Together, we can develop solutions that will help provide you with higher output and value now and in the future. Not only can we provide you with the information you need to make improvements, but we can also help you implement those changes, allowing you to focus on the job at hand.

With the help of our services, you can prevent oil spills and leaks from harming your business. This will also minimize damage to the environment and your equipment. In the case that you are forced to deal with a spill, we also offer an analysis of the methods being used at the time of the spill and can help with containment and clean up.

Things To Consider When You Perform A Mooring Analysis

[Posted on January 29th, 2014 by Bill Stewart]

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Anytime a permanent structure is going to be built into the water, such as a pier, it’s important to conduct mooring analysis. This will help to determine the design of the structure as well as the materials to ensure that all has been taken into consideration. If analysis is not done, it can lead to problems down the road – including complete destruction of the mooring.

Many industries use mooring analysis, including offshore drilling. When an industry needs analysis conducted, it usually involves software where numbers can be added.

The software can generate a significant amount of data after some basic numbers are inputted. This includes looking at the depths of the water as well as such things as the type of water. Waves and tides can play an active role in the analysis as well because a structure needs to be high enough to compensate for such things.

There have been some instances when piers and bridges have been built without considering the highest wave. As a result, the entire structure was washed away when storm waves came crashing down. This left people to lose both time and money because of having to rebuild.

Industries do not have to take the time to learn through trial and error. There are plenty of ways to find out about the conditions of the water and worst case scenarios by conducting mooring analysis. When it comes to offshore projects, riser analysis can be important as well. Generally, anything that tells a person that they will be able to build because of having numbers in front of them to inform them it is okay is needed prior to going forward with a project.

Once a person is out on the water, they have to decide between buoy versus anchor. There are pros and cons to each. In some instances, the buoy can be more effective. It is a form of mooring that can be permanent. Boats can attach to it as opposed to dropping an anchor. This allows boats to stay stable and they don’t have to worry about an anchor dragging along the bottom of the ocean floor as the waves help to push them along.

In many instances, boats are not equipped with an anchor that is sufficient for the water depth and waves that they are in. As a result, they won’t drift as far as not having an anchor but they are still going to drift simply because they don’t have the right equipment. When it’s boating for fun, that’s fine. However, when it comes to offshore drilling and similar projects, drifting could be catastrophic.

Mooring analysis has to be done dilligently to ensure that all of the right equipment is aboard and that worst-case scenarios have been considered to avoid a loss of time, money, and destruction of property.

Why Riser Analysis Is Critical

[Posted on January 22nd, 2014 by Bill Stewart]

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When you are conducting any kind of offshore project, such as drilling, riser analysis is critical. You have to be sure you have the best designs possible, taking into consideration all environmental factors. If you do not have the best design, you may run into various problems out on the water. Accidents and incidents have occurred in the past and you can avoid many if you do the necessary advance planning.

You are always going to deal with waves in the ocean. Depending upon how extensive these waves are, they are going to affect your ability to float your entire operation.

The riser analysis is done to ensure your design has structural integrity. You may have a drilling vessel as well as a wellhead on the ocean floor. The waves in between will determine how much everything is rocking back and forth. You don’t want to run into situations where you don’t have a strong enough cable – or a long enough one.

The analysis will tell you what you need to know. You may need to obtain added equipment before leaving the shore to anticipate various problems. The rise analysis can be done on the computer, providing you with pages of data. From there, you can incorporate this data into other calculations and ensure your designs are sufficient based upon the information you are getting.

Just as you look at mooring analysis when it comes to docking stations, the same has to be done with the risers. Riser diameters and materials are going to play a role, as will the water depths. In many drilling projects, you may be dealing with depths of one thousand feet.

Many of the newer drilling operations are going into deeper waters. This means that designs you had when you were drilling into 500 feet of water are no longer valid. The riser analysis will ensure that you won’t have issues with the waves once you are out there. If you do not perform the necessary analysis, you may find that you are unable to drill effectively because of not making the necessary connections.

If you look at some catastrophic events that have taken place on oil rigs in the past, you can attribute many of them back to not having accurate numbers. Many drilling companies don’t take environmental factors into consideration at the level they need. You don’t want to make assumptions that the waves will only be a certain height or that the water depths will only be so deep.

You have to plan for the unexpected – and riser analysis is going to help. You may have begged, borrowed, and stole your way to obtain enough funds to drill. You will never get investors to give you money again if your project falls apart. A little analysis can go a long way to preventing accidents.

Stewart USA – Flexible Risers for Off-Shore Drilling

[Posted on January 8th, 2014 by Bill Stewart]

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The Off-shore oil and gas industry continues to need flexible risers to build  new structures.  The debates continue over off-shore drilling. No matter who makes the most valued point, the fact remains that it is a lucrative business with more lobbyists than gas stations, so will continue for a long while. Deep water deposits of  raw materials continue to  promise rewards, and the rising fuel cost puts pressure on all governments to go to more deep water to drill.  Oil and gas companies realize a very strong financial drive to pursue more and more off-shore oil rigs.

Risers are in Demand

Continued off shore rig development kept high demand for components that are used to build rigs high.  Among the most needed are flexible risers.  They connect platforms with oil and gas below the ocean, and then transport fuel to where it is packaged and transported. If we did not have risers, much of the oil and gas the world is mining would remain inaccessible.

 Steel Catenaries

The steel catenaries are risers that give benefits others simply do not. These risers are  steel pipes, flexible, and follow the ocean floor to the oil platform above.  They are meant for deep water drilling and often hundreds of meters long.  The first one built was by Shell twenty years ago.  It reached a depth of 872 meters.  These powerful risers operate at pressures between 2,000 and 5,000 psi. Not exactly like the pressure washer you use around your home! The flexible risers are less costly and really reliable, known for resistance to high temperatures, ability to take high pressures and flexible movement.

Technology and Development

Flexible risers s are primarily used in fragile marine settings and  transport hazardous materials through these ecosystems. Cable dynamics are used daily in the operations of oil rigs. Much of the research and development that has gone into flexible risers actually focused on safety and creating these to be as safe as possible. Fluid dynamics, mechanical technology professionals, soil mechanics technology professionals and many other professional personnel work to design the best flexible riser possible.


Flexible risers are not the only type of riser used when for off-shore oil and gas platforms. Another way which is better suited to some specific situations, is the bottom-weighted riser. This is technically not a flexible riser but has commonalities with them. Two distinctive characteristics  of the bottom-weighted riser are (1) its rigid elbow and(2) horizontal section made of titanium.

Flexible risers are usually the best solution but each platform needs a specialized evaluation.  They are each unique.

Stewart Technologies helps companies design platforms and determine which type of riser is best for each individual off shore  platform. STA continues to be the go-to authority for off-shore rigging and its production.


Trends and Uses for Cable Dynamics Today in Off Shore Industry

[Posted on January 7th, 2014 by Bill Stewart]

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Cable dynamics represent a vital part of all offshore technology projects, procedures and error solutions.  High quality technical reports are necessary, including diagrams which enable technical reports to be well understood by not only trained experts but by average lay persons or legal counsel.  Extensive use of computer software and state-of-the-art analytical simulation techniques are vital in today’s offshore industries and their management technology professionals.  A “notebook” computer and printer should accompany technology professionals when  performing their many important offshore duties or preparing  technical reports.   Millions of dollars have been awarded to clients of Stewart over the last fifteen years as a direct result of the expertise and reporting of the owner of Stewart Technology Associates,  W. P. Stewart, P.E.

Cable Dynamics Also Vital in Reenactments

Stewart Technology Associates maintains  databases of offshore and marine mishaps,  spills, and construction.  Other offshore costs factor into their technology projects, databases of construction and other offshore costs. These are most useful in maritime law.  All of the foregoing testifies directly to the expertise of STA company in offshore cable dynamics and other significant marine solutions.

An anchoring system for offshore is controlled by factors such as site environment, operational variables and the vessel  involved in the system.  Its adequacy and ability to stay on site must be checked by proper methods of analysis. The inclusion ofcable dynamics is an extremely important consideration in the analysis of a moored vessel, permitting anchor motion. Then numerically solved timehistories of cable displacements and cable tensions for cable figurations occurring under the Initial conditions are provided through mooring line static equations.  The equations of motion of the moored vessel subjected to an open ocean are then numerically solved, yielding time histories of vessel motions and cable tensions.

An example involving a moored production barge is examined and results compared with previous incidents.  In this way the cable dynamics are used in the proving labs or court of law as importantly as they are used in their offshore capacity.

Steel Risers

Flexible Risers had a set back in recent years but now they are in high demand. The riser components are used to build off-shore rigs very elevated are needed as much as ever. Risers are most definitely needed. These risers connect platforms with fuel deep below the ocean and carry fuel to areas for packaging and transport. Without risers, much of the world’s oil and gas would remain untouchable.

 Steel Catenaries

The steel catenary risers afford industry perks that others don’t. These are flexible steel traveling from the ocean’s floor to the drilling platform. Designed for deep-water drilling, they measure several hundred meters.

Stewart Technology Associates have played an integral part in the development of America’s oil industry, from working the offshore platforms to damages litigation.

Steel Catenary Risers: The Need for Stability

Steel catenary risers are large metal structures used to attach floating rigs, petro-chemical facilities and housing units to the sea floor. These steel risers must be able to withstand harsh currents, extreme weather and a variety of other elements to keep platforms and other structures stable and able to operate as they are intended. The designers of these unique structures must continually monitor how their risers perform, making needed repairs and watching for any malfunction or problem that may arise. New technology enables the manufacturers of the steel risers to continually maintain and improve their riser designs.

By performing and monitoring seakeeping analysis reports, they are able to improve their rises and keep them compliant with both federal and international guidelines. OSHA, the petroleum industry as well as the Environmental Protection Agency closely monitor how the risers handle extreme weather conditions and if they show signs of stress from strong underwater currents. The stability of the deep sea, steel structures is vital to the safety of the workers. It is also important when trying to maintain efficient productivity levels and keep operations moving smoothly.

The EPA relies closely on reports from both manufacturers and the managers of operations on platforms and rigs when it comes to the stability of the steel catenary risers. If a riser fails while supporting an oil rig, the resulting damage can be extensive. Not only would there be damage to the rig and platform, but loss of workers’ lives and extensive amounts of destruction in relation to the environment.

OSHA (the Occupational Safety and Health Administration) is concerned with the health and safety of all workers employed on the rig or platform. Any resulting injuries due to a malfunction of the rig or the breakdown of equipment can result in extremely high fines. Defects found in steel catenary risers can lead to the compromise of an entire platform. Even if no one is injured, an investigation would uncover possible safety hazards that make the platform unfit or too dangerous for operation.

The harsh environment in which risers are placed also plays a direct role in their design and structural integrity. Manufacturers must account for every aspect of the environment from deep sea underwater currents to hurricane strength winds. The force of both sea level and underwater elements can offer distinct challenges for individuals who must design the structures to withstand both extremes at the same time.

Steel catenary risers must be able to, not only support, but secure the platform and protect it from unexpected shifts and changes in the weather as well as the ocean currents. The need for stability is imperative when workers’ lives and the safety of the environment are at stake. Companies must be able to trust the structures they use so they can remain in business and increase productivity.

Seakeeping Analysis

Seakeeping analysis is measuring how a watercraft or any other water vessel can withstand conditions while on the waters. A ship, or a boat in that case, that has perfect sea keeping ability is referred to as seaworthy, and it will be able to operate efficiently and effectively even when in very high seas. What is normally used during such analysis include a number of things among them the steel catenary risers.

Sea keeping ability is measured using the following factors.


This is one of the first things used in seakeeping analysis. Where is the ship intended to operate? Or what will be the role of the ship while on the high seas. Basically, mission is one of the key factors used when it comes to seakeeping analysis.

The Environment

Just like mission, the environment also plays a significant role as it is one of the measures. Normally, what is looked into are the conditions under which the ship or the boat is going to operate. The conditions can be described as wind speed, sea state, and geographic region. Additionally, all these conditions can be combined.

Ship Response

How is the ship going to respond to the external and environmental factors? Ideally, the responses are the function of the environment and the ship’s features and characteristics.

Seakeeping analysis impacts directly on the design of the vessel. Ship motions are very vital for determining dynamic loading of the crew, cargo, structural element and even the ship components. It is put under great consideration when determining key dimensions of the sea vessel. Additionally, it will play a key role when you are creating the general arrangements of the ship interior.

Factors That Affect Seakeeping

When it comes to seakeeping analysis, there are multiple factors that can impact directly on how the ship will respond correctly. Some of these factors are highlighted below.


Practically, the larger the ship, the lower motions it will have than a smaller ship. Why is this case? Ideally the relative size of the wave is lower.


Normally, when a ship is stable, it will tend to follow a wave more close than the one that is less stable. In short, a ship with more stability will have high acceleration, but with very low amplitude of motion.


Displacement plays a key role when it comes to seakeeping analysis. A ship that is heavy will have low motions when compared with a lighter ship.

Human Factor

This is often one of the most critical factors when it comes to seakeeping, especially when it comes to smaller vessels. You certainly have to stay injury free, get sufficient sleep and avoid sickness.


The larger the water vessel, the lower its chances of it immersing. Deck immersion is normally one of the seakeeping analysis criterion. It actually affects the mission abilities of quite a number of water vessels.

Basics and Uses of Hydrodynamic Analysis

[Posted on December 11th, 2013 by Bill Stewart]

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Hydrodynamic analysis, the branch of fluid dynamics that deals with liquids in motion, is an important part of technology anything oceangoing or aquatic. Everything from ships to off-shore structures undergoes some form of this analysis. As the world increases its demand for energy, off shore structures are getting built in more extreme conditions, from deep water to arctic platforms, which require rigorous analysis before being built. Looking toward the future, hydrodynamics is helping solve the uncertainties around tidal generators, possibly turning it into a key energy resource.

Uses in the Energy Sector

The emergence of very large crude carriers has lead to an increase in single point moorings to allow the carriers to load and unload their cargo without the need for a large facility to house them. Given the cost of upwards up $387 million for a single terminal for even one of these moorings, performing solid hydrodynamic analysis is important, as any disruption can have major effects. Iraq is using the moorings to potentially double its output, and is planning to achieve this with only 4 facilities.

For offshore platforms that support drilling, operators need reliable and predictable performance, as well as prediction of wave loads that comes with accurate analysis. The analysis will also determine the safe operation conditions for offshore platforms.

Future Uses

With alternative energy becoming a larger part of the total energy market, tidal generators are being looked at as a way to harness tidal energy to cleanly generate electricity. It is not yet known how much energy can be extracted from the tides, and research is ongoing. This uncertain extends to all scales, from a single device to entire tidal basins.

What to look for

When looking for a company to perform such an analysis, you’ll want to look for a few things to make sure the company doing your analysis will do a good job. There are a variety of software tools used for this analysis, and you’ll want to make sure that the company you’re vetting uses at least some of the following software:










You’ll also want to make sure that the technology company you’re looking for has experience with many projects. While a theoretic background is also useful, teams with experience with real world projects in a variety of different environments will have the background to deal with any problems that come up.

Hydrodynamic analysis is an important part of any technology effort for aquatic structures, and making sure you have a reliable company that uses the latest techniques and software will ensure you get solutions to the challenges you face.

Features of Single Point Moorings

[Posted on December 4th, 2013 by Bill Stewart]

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Single point moorings are loading buoys anchored offshore, serving as an interconnection for tankers load and offload liquid or gaseous products. The buoy contains a bearing system that allows part of it to rotate around the moored geostatic part. A vessel can be able to weathervane around a buoy’s geostatic part when it is moored to it. A moored vessel can then rotate itself into a dominant environment, with the system minimizing loads on a buoy’s mooring system. This system can also be used when a vessel that one would like to moor is approaching the buoy.

Some of the single point moorings buoys are off the shelf products that offer various standard features, while others are custom designed. A mooring system, which consists of lines as well as anchor points, is designed to meet the requirements of a vessel and the local environment. Mooring systems are combined with fluid transfer systems, enabling the connection of subsea pipelines to a tanker. Fluid transfer systems include submarine hoses that are between the Pipeline End Manifold (PLEM) on a seabed and a buoy as well as the hoses that are between a buoy and a tanker.

Fabrication can be provided for single point moorings, including procurement, technology, construction, and logistics. Steel fabrication capacity is required if a company is to sustain the needs of a client who wants to develop oil and natural gas fields in increasingly remote geographic locations. To ensure that a client can achieve production at sustainable costs, steel fabrication facilities have to be able to meet the increasing demand for mooring systems. In addition, the technology and fabrication has to be done in a proper manner. The design and workmanship of the systems should also meet stringent rules that are in force.

Some of the offers available for single point moorings include the fabrication of the buoy body. Components for the mooring and anchoring can also be provided. A customer can also be provided with a product transfer system, such as the ones used for loading or offloading gas or liquid products. Auxiliary components can also be provided, including boat landing, handling, and lifting equipment. Navigation aids and power provisions can also be provided. Once the system has been set up, it could be an independent facility or an integrated system as part of an offshore platform.

Hydrodynamic analysis provides a critical insight into the behavior of water and other liquids, which affects water-borne vessels and related facilities, as well as containers that must manage liquid holding as well as liquid flow. Such an analysis provides key inputs into the designs of water locks or how the engines of a vessel perform with the turbines while producing a boat’s momentum. For a client who is considering a major project such as dredging, vessel production, harbor design, or a new water channel, this analysis plays a vital role in decision making and resource allocation.

Three Ways To Benefit From Anchor Analysis

[Posted on November 27th, 2013 by Bill Stewart]

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When you anchor anything – a boat, an oil rig, or anything else, you need anchor analysis. Using software, you can enter in a variety of variables and learn what is going to happen. As waves and winds are factored in, you will learn whether the anchor you have is sufficient or if you need to explore another option.

There are a lot of things that can go wrong when you anchor a boat. This is why more people in various industries are taking advantage of Orcaflex. This is a software program that can assist with anchor analysis so you can learn more about the environment and help you to choose the right anchor.

If you’ve ever gone in search of anchors in the past, you know there are many options. There are different sizes, weights, materials, and even claws. How you choose an anchor is dependent on the environment you will be in when you need to anchor. If you are in calm waters, you won’t need as big of an anchor as you would where there is a lot of wind.

One way to benefit from anchor analysis is to be able to calculate worst-case scenarios. The anchor you buy may work at one wind speed but once the wind increases, it may cause more waves. This may be sufficient enough to pick the anchor up from the ground, which means your boat or other vessel is no longer anchored.

Another way to benefit is to figure out what you need for the environment you will be working in. You shouldn’t have to buy multiple anchors to try and figure out how to keep your vessel in place. This can be a costly game of trial and error. The better solution is to make calculations and purchase the anchor you need the first time around.

Yet another way to benefit from anchor analysis is to learn what issues you could encounter. This will make it easier to train your employees on what should be done in the event you get into deeper water or the weather takes a turn for the worse. When your employees are trained in these situations, you can ensure that things go as planned.

There are too many accidents on the water because no one bothers to analyze their needs. They make a quick judgment call and hope for the best. You cannot risk lives and risk damaging equipment all because you couldn’t be bothered with some analysis.

There are firms and software programs available to help with anchor analysis. This means you have no excuse not to obtain the analytical reports you need prior to going out into the open water. Your anchor needs to work, regardless of the conditions that you could potentially face. You just need the reports to tell you the details.

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