Bill Atkinson, Tri Tool, USA, explores how a custom engineered tools like the deep counterboring system is helping contractors reach faster production rates for pipeline fabrication.
Shell Oil is developing Appomattox, the deepest oilfield ever in the Gulf of Mexico. Custom engineered tools, like the Deep Counterboring System is helping pipeline contractors achieve unprecedented efficiencies in productivity, while maintaining the extreme precision and reliability demanded by a project of this scope.
Taking the plunge
In the past, exploring and drilling for oil and gas has logically been carried out where the deposits were relatively easier to reach and at shallower depths. With the ever-increasing worldwide demand for petroleum, however, major producers have needed to pursue energy reserves in expansive, rich deepwater reserves. Advancements and improvements in platform design and fabrication, pipeline weld integrity, custom engineered tools, and more effective drilling techniques, have permitted exploration where it was never physically possible or economically feasible.
Today, with higher and higher levels of project costs, regulation, workforce planning and strategic product transport concerns, even oil industry superstars must be very cautious when making investments in new production. New developments in deeper regions of known potential must be carefully weighed against a backdrop of economic, environmental and geopolitical uncertainties. Despite these and many more challenges, groundbreaking new developments are proceeding, with the promise of tapping into some of the largest and most valuable oil and gas reserves ever discovered.
A perfect example is Shell’s Appomattox project, located in the Gulf of Mexico about 80 miles from Louisiana in 7200 ft of water. Appomattox was officially launched in July 2015. When completed, it will be Shell’s eighth floating platform in the Gulf of Mexico. Shell operates Appomattox with an 79% interest, with development partner Nexen Petroleum Offshore holding the remaining 21% interest.
The new development is comprised of a semi-submersible four column production platform, six subsea drilling centres, 15 producing wells and five water injection wells. By 2020, when construction is scheduled for completion, Appomattox will be the largest floating platform in the region. The project’s peak production from the fields is estimated to be approximately 175 000 boe/d. Combined with adjacent deposits, it is estimated that the aggregate potential development could reach approximately 650 million boe.
Deeper water, heavier walls
As can be imagined, drilling and transporting oil from significantly deeper depths requires considerably higher volumes of pipe. Another important issue facing project planners was that much heavier pipe wall thickness is required to withstand the forces of the deeper water. It was clear that implementing cutting-edge fabrication expertise would be essential to ensure that each pipe weld joint performed with the highest possible integrity. To ensure top-level efficiency throughout all aspects of the Appomattox project it would be critical that each and every contractor performed with a high degree of co-ordination. Already, the project has been amazingly efficient, reducing total costs by 20%, largely due to innovative structural design improvements. These include advancements previously established with earlier four column production hosts, such as the Olympus tension leg platform.
For Appomattox, Shell needed a prime contractor and subcontractors with a proven track record of success with onshore pipeline fabrication, and the ability to determine and deploy the most effective pipeline equipment and latest pipeline technologies. Pipeline Technique LLC (PTL) was placed in charge of all onshore pipe fabrication. PTL, in turn, chose Bayou Companies LLC in New Iberia (Louisiana, USA) as its base of onshore operations. With Bayou’s strategically located facility on the Gulf Coast, its top-notch yard was the perfect choice to move the requisite high volume of pipe. Bayou’s site also had an ideal, long-proven layout and the configurable area needed to set up a large modular pipe processing rack, with plenty of loader access for the extensive lay down storage between the numerous pipe processing stages.
With the increased forces deepwater pipelines are subjected to, optimal weld results are mandatory, and excellent welds require meticulously accurate weld end preparation. To achieve this in a rapid, repeatable way involves laser accurate pipe end counterboring and dimensioning to guarantee that the seemingly endless pipe sections stacked onsite were all made ready for the subsequent high volume weld beveling, welding and pipe (anti-corrosion) coating operations to follow.
High volume pipeline fabrication solutions
Tri Tool® has had a long, successful relationship with PTL and its parent company, Heerema Marine Contractors (HMC), as an OEM supplier of both standard and custom engineered tools like Tri Tool’s pipeline equipment and portable machine tools. Over the years, Tri Tool has designed and manufactured a wide range of PFMs, ILUCs and special deep counterbore equipment to support pipeline fabrication. New product developments at Tri Tool reflect the company’s focus on higher volume pipeline fabrication technology such as specialized laser pipe end dimensioning systems and advanced ID bore laser profiling and video inspection applications.
It was exactly for high volume pipeline fabrication challenges such as the Appomattox project that Tri Tool had been developing its proven 7-Axis CNC Deep Counterbore System with patented laser alignment, that combines increased machining speed with unprecedented precision and reliability. In a case of perfect timing, Tri Tool’s new counterbore system had just completed performance trials and final computer software development. Tri Tool had the opportunity to demonstrate its new system to PTL project supervisors several times, and particularly important was the ability to utilise pipe that was intended for the Appomattox project. As a result of successful preliminary testing, Tri Tool’s CNC Deep Counterboring System was selected for use on the Bayou site for the counterboring step of the fabrication workflow.
This simple yet versatile computerized positioning technology is a vast improvement over conventional counterboring methods. This innovative technique places the pipe end in a fixed position relative to the 7-Axis cutting head. A patented laser alignment system is integrated into the computer console that directs the entire counterboring operation. The laser scans the circumference of the pipe at two distances from the end. The computer then resolves the exact centre of the two scan circles to rapidly determine the true centreline angle of the pipe end to precisely align the cutter mechanism to the pipe.
The computer then calculates the optimal cutting parameters. The cutting head can be positioned in seven distinct axes, resulting in an incredibly precise and rapid machining operation – one of the keys to the short cycle time. Important to note is that once the pipe has been engaged into the counterbore equipment, the pipe can remain stationary until the machining process is complete. Other systems required that pipe orientation to the counterbore cutter be achieved by moving the entire pipe, a slow and unwieldy process.
Fully mechanized for maximum safety
Having rapid counterboring equipment is ineffective unless you design and build a corresponding pipe handling system that can complement the speed and efficiency of the counterboring equipment. A wholly new approach to counterboring was going to require a completely new technique for pipe handling. This need resulted in a new, modular, gravity-fed and expandable pipe rack system. Custom engineered and designed simultaneously with the CNC Deep Counterbore system, Tri Tool engineers looked at ways that pipe sections were handled in high volume fabrication yards. Working under the ‘Safer by Design’ concepts, it was clear from industry knowledge that manual handling of pipe in racks was a known hazard that needed to be eliminated.
A decision was made to produce the industry’s first (maximum safety) fully mechanized rack system where the pipe is loaded into one end and the pipes are either positioned hydraulically or by gravity until they are removed by a loader at the other end. This rack’s ‘Hands Free’ operation is the safest and fastest in the industry: two aspects of project management that were important considerations for PTL and the Appomattox project supervisors. Independent workstations are logically positioned along the rack to allow separate staging and operational positions. Pipes do not only proceed in a linear fashion, but can also be moved laterally to the pipe flow. This factor was an important advantage, permitting pipes to be driven on rollers lengthwise into one of the two separate modular (shipping container housed) 7-Axis Counterboring workstations (one for each pipe end).
This custom engineered pipe rack system offered other advantages as well, in the form of rapid expandability. The supports for the pipe rack were placed on portable steel base plates that were deeply secured with long stakes. Each support footpad was held in place by strong, inexpensive angle-iron retainers welded to the base plates. Each time the rack needed to be moved, the angle iron could be cut free, then re-welded quickly and easily after the move without damaging the rack. One half of the entire rack (along with corresponding workstations) can be moved perpendicular to the pipe flow to easily accommodate longer or shorter pipe sections.
With many years of successful experience performing strategic equipment shipments to domestic and international pipeline contractors, Tri Tool’s modular equipment was specifically designed for rapid response anywhere in the world. The CNC Deep Counterbore System was fully containerized with the entire mechanized pipe rack system in one 40 ft unit, the dual counterboring machines (one unit for each end) were in two 20 ft containers. Two smaller 10 ft containers held additional project support material and performed double-duty as the dual laser dimensioning workstations.
Upon arrival to Bayou’s New Iberia worksite, grounds were prepared and the gravity-driven mechanized pipe rack was positioned and angled vertically for optimal pipe flow.
Measuring precision for the record
After pipes are counterbored – first one end and then the other, they are staged for the next important step in the process: laser dimensioning and data recording for counterbore verification. The 7-Axis deep counterbores are so uniform and dimensionally correct, when the ends are fit-up at the welding stage, pipes do not require being rotated or ‘clocked’ to try to find the closest dimensional match-up. During laser dimensioning, accurate temperature measurements are taken to account for thermal expansion and establish the reference temperature of the pipe when data was collected.
After the LDS had precisely measured the pipe ends, the data is recorded in a control console in each workstation. Information regarding each counterbored end is then routed to a control booth where pipe end inspection reports were prepared and sent in real time to the project managers for immediate documentation, one of Shell’s mandatory quality control procedures on this project.
Tri Tool custom machine tools and equipment solutions present on the Appomattox project were not limited to the 7-Axis CNC Deep Counterbore System with its mechanised pipe rack, and the LDS systems. Additional Tri Tool equipment that was instrumental to the fabrication workflow on the Bayou site included TRIMAX® Split-Frame Machining Systems that provided high speed weld cut out capabilities for quality control, PipeMaster® PFMs used for weld preparation beveling, and ClampMaster® ILUC internal line-up clamps.
Tri Tool equipment is also currently deployed in South Korea working on the construction of the Appomattox platform that will eventually be transferred to the Gulf of Mexico.
A world-class challenge
Sometimes it takes a world-class challenge to establish the true dependability and efficiency of world-class equipment solutions. In the end, the most advanced computer aided design and quality manufacturing do not matter if a machine system cannot prove its worth in the pipeline fabrication arena. When custom machine tools pass the ultimate test of being worked hard day after day (as has been the case with the equipment utilized on the Appomattox project), the difficult equipment selection process by project management is validated.
Due in part to the large scope of work, project planners committed extra time and costs to co-ordinate separate stages of the fabrication process until such time as actual equipment performance levels and cycle times were established with certainty.
Even though the onsite counterboring and dimensioning start was delayed by several weeks, this phase of the work was completed two months ahead of schedule. What that means in practical terms, is that in the future project planners can count on the speed and precision of the proven CNC Deep Counterbore System to support large scale onshore pipeline fabrication operations, the Appomattox project serving as a prime example.
It also means that fabrication welding contractors know that they can plan reductions in project timelines based on the deployment of fast and accurate new counterboring techniques that are upstream from their high volume weld prep and welding operations.
To summarize the effectiveness of the new custom designed CNC Deep Counterbore System performance on this phase of the Appomattox project, after approximately 20 000 pipe ends were successfully completed, the resulting production rates were up 60% faster than competing (manually adjusted) counterboring systems. In addition counterbore surface finishes to 50 – 60 RMS required no additional finishing work, a major time saving.
Custom engineered tools, such as the machinery that performed onshore fabrication for the Appomattox project, can make a significant positive impact on a project’s timeline and expenses. Along with proven equipment, you can benefit from experienced, safety trained onsite service personnel who can provide expert workforce augmentation for any of your most challenging projects.