Blog • Page 5 of 9 • Stewart Technology AssociatesStewart Technology Associates | Structural, marine and offshore specialists | Page 5

Steel Catenary Risers for Off-Shore Drilling

[Posted on July 9th, 2014 by Bill Stewart]

Bookmark and Share


Steel catenary risers (SCR) are well-known tools used for uniting an ocean pipeline to an oil production platform. SCRs enables the movement of liquids such as water oil, and gasoline. When combined with anchor analysis, SCRs can be used precisely to improve the efficiency of virtually any drilling operation.

Steel Catenary Risers

There are several, basic components which all SCR’s have in common. First off, the SCR is connected to the platform via a coupling known as a flex joint. The riser may lie on the floor of a body of water, hundreds of feet below the surface, for this reason several buoyant must be attached so the SCR will remain buoyant. Increased buoyancy reduces the stress put upon the flex joint. If the joint was forced to support the entire weight of the riser, it would be far more likely to come undone. The riser must also be held in place on the floor of the body of water. Riser anchors must be strategically placed along the length of the riser so currents don’t move it from the desired position.

Why are SCRs Used Underwater

Many people are familiar with the oil production in the Persian Gulf and in the US in states like Texas. However, 3/4 of the Earth’s surface is covered by water, which means most of the viable drilling spots in the world lie beneath the sea. The dry land drilling sites would never be able to satisfy the world’s petroleum needs, which is why off-shore drilling is being discussed so heavily by the governments of the world. Even those who protest the use of fossil fuels still support off-shore drilling. This is because the vast majority of the world’s natural gas also lie beneath the surface of large bodies of water. Steel Catenary Risers can help to improve the world for everyone by making natural gas more accessible to replace harmful fossil fuels.

Other Benefits to Off-Shore Drilling

The US still has a volatile relationship with many of the world’s top oil producing countries. However, the US is also the country most dependent upon the fossil fuels from these countries. Off-shore drilling could make the US less dependent upon all foreign fuel sources, by providing ample petroleum and natural gas. Independence from foreign energy sources is certainly a great incentive for off shore drilling. Many European countries are also exploring off-shore drilling as a means of freeing themselves from dependence upon Russian natural gas. The Moscow based company Gazprom has been accused of using Russia’s natural gas reserves as political weapons which has countries such as Germany seeking more viable solutions. As off-shore drilling becomes more common, the need for steel catenary risers will increase as well.

Single Point Moorings Help Offloading Efforts

[Posted on July 2nd, 2014 by Bill Stewart]

Bookmark and Share


When drilling platforms need to transfer gas or liquids, single point moorings help their offloading requirements. Properly designed and anchored, these moorings can secure tankers of any size safely.

Offloading crude oil or gas to single point moored tankers is vital to getting platform production from the ocean to land-based ports. This connection between tanker and platform at a single mooring point with proper subsea design and installation makes the critical transfer of platform production easier, faster and more effective. Understanding how  single point moorings work is important to ensuring their subsea design and connections are installed properly effectively holding weathervaning tankers securely prior to and during gas or liquid transfer.

Working Description of Effective Mooring Systems

Three primary components make up mooring systems.

  • A mooring line;
  • An anchor: connecting the mooring line and a floating buoy; and
  • Various connectors, establishing the vital link of tanker and offshore platform.

Mooring lines often use different material, based on subsea and surface environmental conditions, such as wind strength, wave size and motion, and current power and direction. The most popular materials are —

  • Synthetic fiber rope;
  • Steel wire rope;
  • Chain; and/or
  • Combinations of the three materials used together for added strength.

Long-term and permanent moorings typically feature lines using chain, particularly in shallow water (usually defined as up to 100 meters). Deeper water mooring lines often use steel wire rope, maximizing the benefits of its lighter weight and increased elasticity as compared to chain. When light weight is the top consideration, mooring systems feature synthetic fiber rope, for its lighter weight properties.

Deeper water moorings, up to 2,000 meters, suggest using chain or chain and steel wire rope configurations. Combinations of all three popular mooring line materials are often used in deep water, over 2,000 meters, to get the best features of strength and elasticity.

All mooring system success depends on the strength and ‘holding capacity’ of their anchors. Outstanding anchors’ holding ability depends on their digging depth and the soil components of the sea floor. The most popular anchor type is the drag embedment style, used throughout moorings in the Gulf of Mexico.

Installing this anchor involves dragging it along the seabed until it achieves its optimal depth, penetrating sea floor soil and creating necessary resistance to hold it in place. Deep water conditions favor suction pile-type anchoring, since drag anchors lack high performance when heavy vertical forces dominate the environment, such as the pressure generated by deep water.

The third primary anchor type, vertical load devices, while similar to drag anchors perform well when facing both horizontal and vertical load issues. These types are very useful when mooring lines tend to adopt angular positions between anchor and buoy.

Steel catenary risers help the most common mooring system for shallow water allow the line to modify configurations as the surface vessel moves around. Since the mooring line lies on the seabed, it needs to be longer than water depth, increasing its weight, making catenary mooring systems less efficient as water depth increases.

When platform owners want expert advice and analysis of single point moorings, they turn to Stewart Technology Associates, industry leaders in offshore equipment and systems expertise. Our state-of-the-art technology and extensive experience analyzing and designing offshore systems help develop efficient solutions for offshore drilling and production platforms. Analysis of mooring methods is only one area of the many conditions we evaluate for our clients.

Stewart Technology Associates Improves the Seakeeping Analysis for Shipping

[Posted on June 25th 2014 by Bill Stewart]

Bookmark and Share

Stewart Technology Associates are experts in mechanical and geographical technology of the offshore industries seakeeping analysis processes. This is the essence of the STA marine strategies. This company has brought Jack-ups and liftboats to aid marine offshore businesses for years. It also provides information that leads to correct calculations in the preparation of shipping conditions.

As an expert in the field the president of this resourceful technology company, Mr. W. P. Stewart, is a leading person in the mariner field. Called upon in events concerning sea related accidents, Bill Stewart is a seasoned expert. This company developed the jack-up simulator, both physical and software simulators and provides the service of oil spill clean up. The company is involved with risk assessment for mariner equipment.

Established in 1986, STA is qualified in geotechnical technology. The company’s devices have improved the safety and methods of factoring mooring analysis for vessels and the use of training simulators. This company’s equipment is used to further the preparedness of water safety agencies in many countries. Seakeeping analysis has been a part of Mr. Stewarts training for over twenty years and remains a part of his expertise. This Houston based firm provides offshore training equipment for a long list of mariner companies.

Using the companies design and analysis services to improve sea operations this company caters to a number of clients around the globe, up grading the necessary software and equipment that keeps oil rigs and seafaring equipment moving. The mariner community is limited to a few experts and Bill Stewart of Stewart Technology Associates happens to be one of them. Developing tools that propelled shipping into a better industry, the jack-up simulator and the ballast control simulator, this company is standing on the forefront of mariner innovations.

Stewart Technology Associates has acted as a marine specialist making pipe/pump software packages, these items are updated by the company. Mariner developers around the world use the technology developed by STA, with Jack up simulators distributed as a separate item or connected with the full simulator.

Heavily qualified in Seakeeping analysis, STA has the ability to effectively determine if a vessel is able to maintain its integrity in the sea environment. People trained to deal with oceanic conditions are trained on simulators designed by Stewart Technologies Associates.

Ships and barges are a part of the scenery today out on the sea but these water vessels need trained people and strong materials to keep them afloat. This company has developed a strategy that test equipment, trains people and keeps equipment sea worthy, allowing them to test and calculate a vessels seaworthy ability before it is challenged by the oceans fury.

OrcaFlex Software Has Multiple Talents

[Posted on June 13th 2014 by Bill Stewart]

Bookmark and Share

Technology plays an important role in offshore and marine industries. OrcaFlex software has multiple talents to help with structural dynamics and hydrodynamic analysis of structures.

Designed by mechanical and software engineers, naval architects and mathematicians, this software was developed by Orcina Ltd. professionals to analyze diverse marine systems.

Some Features of This Software

This top-rated software assists in the design of the following marine systems.

  • Riser systems;
  • Mooring systems for offshore structures;
  • Installation plans for diverse scenarios;
  • Towed offshore systems; and
  • Defense systems, marine renewables and seabed stability solutions.

With its incredible power combined with a wonderful GUI, this software package is the optimum marine services program available today. Its sister software, OrcaLay and OrcaBend work in concert to provide pipe lay and bend stiffener design and analysis.


The software helps with design and installation of production risers. Needed to transfer fluids to and from vessels, these conductor pipe systems are essential to the efficiency of deep water production systems.

OrcaFlex software also offers assistance with both types of drilling risers. When designing and installing marine drilling risers, which typically are used by floating drilling vessels, and tie-back risers, used by fixed drilling platforms in conjunction with surface blowout preventers, help anchor either single high-pressure pipes or sets of concentric pipes.


Also known as single buoy moorings, single point moorings keep one or more tankers stationary while offloading gas or liquid from platforms. The software allows users to plan how to deploy the buoys for maximum efficiency.

CALM (Catenary Anchor Leg Mooring) buoys include multiple legs (tethers) and a turntable, allowing vessels to “weathervane” while accepting the transfer of fluids from platforms. Mooring tankers to these buoys gives platforms more flexibility to transfer gas or fluid in varied weather and sea conditions.

The software’s excellent GUI, graphically displays the alternative deployment options to most mooring designs, allowing users to visualize, analyze and evaluate the best choice for installation. Instead of costly trial-and-error methods, OrcaFlex shows the variety of available options for deployment.

Other Applications

Along with displaying multiple options for the vital deployment of risers and moorings, OrcaFlex offers other applications, making it one of the most versatile programs in the marine industry. Other valuable applications include the following items.

  • Installation evaluation and analysis;
  • Buoy system options;
  • Hose variations, including under-buoy, offloading and floating hose systems;
  • Defense issues, including minesweeping research and helicopter landing options; and
  • Renewable energy systems, including wave power and wind farm modeling.

It is evident that OrcaFlex software helps companies and consultants plan, design and deploy the primary marine systems applying to both vessels and offshore platforms. Stewart Technology Associates specializes in using this technology to deliver our outstanding marine consulting services.

Our extensive expertise, combined with this powerful software package, gives us the tools to design solutions to most marine-related issues. We also feature forensic analysis to identify prior problems or create evidence for expert testimony responsibilities. Combined with our riser and mooring experience, we offer a wide variety of efficient solutions for a myriad of structural and offshore marine systems.

Marine Accident Investigation Expertise is Critical for Answers and Liability

[Posted on May 28th 2014 by Bill Stewart]

Bookmark and Share

Marine accident investigation events are no simple matter. Unlike the world of land-based transportation, marine accidents can often involve far more factors, especially due to the nature of the weather and water conditions at the time. As a result, a good investigation will include the basics as well as advanced review of the facts and data through hydrodynamic analysis, for example.

There is a reason for the intense scrutiny of marine accident investigation reports and summaries. The National Transportation Safety Board, or NTSB, is often involved and a key player in any investigations that take place, especially serious accidents that involve multiple injuries or death and a commercial vessel. The U.S. Coast Guard can frequently become involved as well. As a result, it is critical for a boat owner or title holder to make sure that any investigation that does occur is performed with the right skill, experience, background and knowledge. Very often, the results of reports can trigger financial responsibilities as well as serious penalties.

Marine accident investigation work can also include any type of installation or facility on major waters as well. Oil rigs, for example, are a prime facility that could have issues and trigger multiple investigations on an accident, especially if the results have both life and environmental impact on a wider scale, such as the Deepwater Horizon accident.

In both type of cases, the investigation work doesn’t stop with the field review and conclusion of what occurred. Expertise is often needed in the legal matters and potential trials that come later, assigning responsibility and blame. Without a good marine accident investigation expert’s testimony, a vessel or facility owner could be sitting with a big target on his back even if not actually at fault.

Stewart Technology Associates can provide a client assistance in both field review as well as impartial expert witness testimony on a marine accident or accident complex. Their depth and knowledge in marine traffic and operational matters is extensive, and their professionalism often shows itself during some of the most critical points of an investigation. A client utlizing the help of Stewart Technologies will be able to focus on other aspects of operations, recovery and assistance knowing that Stewart’s team will handle the accident review completely and comprehensively, from the initial water site to the courtroom if needed.

So if your firm is finding itself in the headlight glare of a marine accident investigation or you need a second-opinion on reports that have been produced, Stewart Technologies is the expert to call. Don’t wait; it could cost your firm far more.



Trusted Comprehensive Hydrodynamic Analysis by Stewart Technology Associates

Small firm with top scientific specializations trusted for integrity

The Stewart Technology Associates team of specialist technology experts are highly educated with top scientific degrees, and universally respected for their research and top-level experience in world-wide hydrodynamic analysis projects. Stewart Technology Associates, (STA), specializes in design and analysis of offshore engineering projects and many marine engineering applications. In the current global economy, it is critical for our  clients in the oil & gas industries to push further offshore to find energy supplies that can meet the world demands.

We offer integrity and cutting-edge innovations for offshore structures, drilling processes and production equipment builds that continue to need unquestionable reliability, safety and predictability. STA places a strong emphasis one trust and dedication to the responsible use of highly technical knowledge. This top engineering firm enjoys worldwide respect for design proficiency and multi-level analysis.

Hydrodynamic Analysis

During close to 25 years of excellence in performing hydrodynamic analysis to help world acclaimed marine organizations solve their most difficult challenges and complex obstacles, we have developed top-grade experience involving jack up analysis, pipe lay analysis, CE marking and expert witness testimony, plus much more.

Detailed hydrodynamic analysis of an engineering design or product:

  • Scientifically predicts flow characteristics of bodies of water, body surface parameters expected to impact during the operational phases of the project.
  • Is critical to simulate and test submersible components, underwater power systems and marine architecture.
  • Extends the test data into further professional grade analysis of factors such as stress or vibration on marine structures and pipelines.

Use of Engineering Software to Analyse Flexible Risers

We use the world’s leading engineering software to design and analyze many types of marine systems including risers, mooring systems, marine renewables, towed systems, seismic arrays, seabed stability, and defense. Our first choice in professional engineering software for marine work is Orcaflex, because we get best in class GUI, scientific automation, and visualization. In the case of analysis for riser use,  types of steel and metal alloys, like for catenary risers and other tough marine technology project services, this software allows STA to offer flawless flexible riser design and completely accurate analysis that will exceed the client’s expectations.

Stewart Technology Associates tackles the tough science to make your project succeed

Under the professional leadership of Bill Stewart, CEO, our science and technology team has accomplished laudable worldwide projects and developed an esteemed customer base of U.S. government agencies, large and small oil industries, financial institutions and drilling contractors all over the world. Contact STA Tool-Free in Houston, by phone (713) 789-8340 or email, [email protected], for more details. 

Flexible Risers Are Regularly Used In Offshore Drilling

[Posted on May 14th 2014 by Bill Stewart]

Bookmark and Share

When you are engaging in any kind of offshore drilling activity, it requires a significant amount of analysis. You need to bring a lot of specialized equipment onto the water with you and that’s where you will remain for months at a time. You cannot afford to make mistakes while you are out there, so the use of flexible risers along with detailed analysis is a must. Risers are used to serve as the connection between the drilling facilities and the subsea developments in the field. You will need to understand cable dynamics to account for all of the waves and other environmental factors while out in the water. Since you have a conduit in place, you cannot afford to disrupt the transfer in place and that is why flexible risers are commonly used. It offers, as the name implies, some flexibility to the overall structure of the drilling configuration so that you and all of your equipment are set up to the highest level out in the water. As you go into deeper water, you experience more pressure, more waves, and colder temperatures. All of these factors have to be a consideration so that you have the right equipment. Analysis of the riser configurations will ensure that you have considered all possible scenarios to avoid any kind of disruption to the material transfer. The flexible risers are going to act as a pipeline for vertical transportation. Should you be unable to find the riser that you need, the product would have nowhere to go because a vertical motion is required. As you gather the materials that are required for your offshore drilling, you need to take advantage of all the analysis that you can. Depending upon what you are drilling for and the depths of water that you are going into, you will need different types of equipment. If you fail to get the risers that are needed, your drilling expedition will not be as effective as you hoped. One of the biggest problems on the water is that you do not have access to more materials. Should someone have to bring supplies out to you, it leads to higher costs. When there are unplanned for costs, it can lead to a loss of investors – or the need to bring in more investors. Neither of these is ideal, which is why some planning before you ever take to the water is a necessity. Flexible risers provide you with the needed flexibility when you need a vertical connection so that you can move materials from the sea floor to the facility on top of the water. You don’t have to guess at what you need because advanced technology can run the scenarios and provide you with the in-depth analysis to tell you what the riser configuration should be and what you will require.

Stewart Technology Associates, Experts in Cable Dynamics

[Posted on May 7th 2014 by Bill Stewart]

Bookmark and Share

The ocean is still a vastly unpopulated and under-explored region. This is true so much so that it still holds a fascination for people that live in an age of unprecedented technology and exploration. It is the last place on Earth that man has not conquered. As an unforgiving and dangerous environment, man has to be able to overcome, or work with, the elements of the sea. As experts in our field, we provide solutions for that purpose. Welcome to Stewart Technology Associates, the experts in cable dynamics.

While some want to experience life underwater for recreational reasons, others need to get through the ocean’s depths to drill for oil or gas, two of our most important natural resources, without destroying the pre-existing ecosystems. To do this, we at Stewart Technology Associates use a variety of tools and technology, including Orcaflex, a product created by Orcina. Our solutions are safe and effective, providing solutions without causing environmental damage.

Orcina is dedicated to serving the marine and offshore markets with software, analysis and assistance for oceanographic research, compliant marine renewables, seismic studies, ocean engineering and matters of defense. To ensure quality, Orcina only hires the top professionals in their fields, such as software engineers, naval architects, mechanical engineers and mathematicians. The benefit of this knowledge is displayed in the quality of Orcina’s product, Orcaflex. At Stewart Technology Associates, we combine Orcaflex with our expertise in cable dynamics to deliver the solutions our clients are searching for. We do this with our responsibility to the environment in mind.

One of our environmentally-friendly accomplishments has been the development of our flexible risers. In fact, we are well-known as the leaders in our industry for these risers, due to the quality of their design and the corresponding analysis services. We provide our clients with the benefit of our experience, plus the resources and technologies we have at our disposal, such as the Orcaflex software.

These risers have the ability to help protect the fragile ecosystems offshore drilling takes place in, helping us maintain our commitment to the environment. They also aid in the safety of offshore workers and increase productivity. With the ever-increasing cost of fuel, risers are beneficial and even essential, as they help with construction and production on offshore oil and gas platforms. <

The risers we can provide are cost-effective, made of flexible steel and are extremely reliable in a variety of environments. They are resistant to high temperatures and are able to take high pressures without giving. This ensures their eco-friendly use in an offshore or marine environment. We are able to use these in meeting the needs of our clients by providing the solutions they are looking for. With the tools and technologies we have at our disposal, Stewart Technology Associates delivers the solutions our clients need, when they need them, making us the leading experts in cable dynamics.

How Anchor Analysis Can Ultimately Save Your Project

[Posted on April 23rd 2014 by Bill Stewart]

Bookmark and Share

Whether you are in the oil drilling industry or any other offshore venture, you need to be aware of how anchor analysis is a necessity. When you use an anchor in the water, there are a lot of variables that need to be considered. If you fail to use worst-case scenarios in your analysis, you may not be prepared for what you actually face on the water.

Every day, there are maritime accidents in the news. Much of these have to do with the boats and rigs being unprepared for the conditions. It is likely that you are going to be in the deeper seas and this means being exposed to depths that require seakeeping analysis.

You have to know what to expect before you go out onto the water and at Stewart Technology, we use the latest OrcaFlex software to tell us about various conditions in order to provide anchor analysis. We take a variety of factors into consideration, including:

  • Depth of water
  • Height of sea swells
  • Salinity of water
  • Temperature of water
  • Likelihood of waves

The more that we know about the sea conditions, the better we can advise on using an anchor. Steel anchors are commonly used in order to anchor a boat or a rig, but you have to be sure it is of the best alloy and that there is enough chain attached to all of it.

Various types of anchors are used as well. If you do not use one that is heavy enough, the waves are going to push the anchor along the sea floor. This is going to cause you to drift significantly, which is what you may be trying to avoid. You can avoid accidents simply by having the right anchor in place – and that is the kind of analysis that we provide to our clients.

Your project is likely of the utmost importance. If it is like others within the industry, it is expensive with various investors involved. You cannot risk having an accident that prevents you from completing the project because it could mean the end of your business. A bad reputation is the last thing that you want to create while on the water.

A little bit of planning with anchor analysis can ensure that you are well-prepared for all of the elements when you go out onto the water. We will establish worst-case scenarios so that you are prepared for anything that Mother Nature may throw at you. From there, you can choose the best anchor as well as other equipment so that your project can be carried out regardless of the conditions that you face.

You cannot always do the analysis on your own and when you want a third party to weigh in, it can save your project from disaster.

Web Marketing by Server Side Design, Inc.
Owner of is entirely responsible for all content on this web site. Email