MMS Engineers are faced with approving a variety of projects that can be influenced by VIV (Deepwater risers, Pipeline spans over irregular bottom topography subjected to strong bottom currents, onshore elevated pipelines subjected to strong winds). MMS engineers need to be aware of the potential for VIV to damage such structures and various options that can be useful in mitigating VIV.
Vortex-induced vibration (VIV) is an important issue in the design of deepwater riser systems, including drilling, production and export risers. The VIV can produce a high level of fatigue damage in a relatively short period of time for risers exposed to severe current environments. The wake interference between various risers in the same riser array may also lead to collisions between adjacent risers. Suppression devices, such as helical strakes or fairings may be needed to prevent unacceptable levels of fatigue damage.
When a subsea pipeline reaches the end of its useful life, it must be abandoned or removed. Currently, subsea pipelines are de-inventoried and purged until the hydrocarbon levels are undetectable before abandoning them in place or the pipeline is de-inventoried and purged until the hydrocarbon levels are undetectable before recovering the pipe as scrap. The common practice in both the U.S. waters and the North Sea is to abandon the pipeline in place which, for this study, was used as a baseline for comparison against other removal options currently used around the world.
The Banff 2003 Pipeline Workshop focused on Management of Pipeline Integrity. Workshops and forums provided a free exchange of information and ideas to promote the management of integrity, safety and risk of the pipeline infrastructure. The Banff/03 Workshop was held in Banff, Canada and is the sixth in a series of workshops that Natural Resources Canada has organized to address new pipeline technologies.
Subsea pipelines are increasingly being required to operate at higher temperatures and pressures. The natural tendency of a pipeline is to relieve the resulting high axial stress in the pipe-wall by buckling. Such uncontrolled buckling can have serious consequences for the integrity of a pipeline. Consequently, to date, the industry has sought to restrain pipelines by trenching and burying, or relieving the stress with in-line expansion spools.
This project was to develop and demonstrate a multifunctional system for monitoring pipelines in the field using currently available sensing and communications systems, including the CANMET MIC sensor and chemical sensors to measure pH and CO2 concentrations. The system will use a fiber-optics backbone, with a capability for data acquisition / management and decision making. The ISPIR system will integrate pipeline monitoring, sensing and communications, using fiber configurations and procedures.
The majority of pipeline design codes are based on stress-based design methods. Although conventional stress-based design covers most pipeline applications, it does not cover the design of pipelines that may experience high strains like those of the deepwater GOM and Arctic regions. Similarly, high strains can occur to most any offshore pipeline due to ground movement, unsupported spanning, and seismic loading therefore an exacting site-specific analysis including loading conditions and material mechanical properties is needed to maintain the acceptable level of pipeline safety needed.
The objective is to evaluate current and candidate methods for detecting and monitoring corrosion damage in risers and develop ranking criteria for riser inspection. Offshore pipeline failure statistics have been collected for more than 30 years now. Pipelines predominantly fail as a result of corrosion. Pipeline Risers are the part of the pipeline system that fails most often. Risers are either visually or internally inspected. Due to outside coatings visual inspection can be inefficient and inaccurate.
The U.S. MMS/DOT is sponsoring on offshore pipeline operations and integrity. The workshop took place February 26-28, 2003 in New Orleans, Louisiana.
The objective was to bring together worldwide experience in operating and regulating offshore oil and gas activities in order to identify/disseminate pipeline issues and knowledge for continued safe and pollution free operations.
You can visit the website at http://www.projectconsulting.com/workshop2003/index.htm.
This Joint Industry Project (JIP) investigated how the soil that exists around buried pipelines interacts with the pipe when under some type of motion or force. The results from this work will be used in all three MMS regions and allow for better understanding on how soil forces act on the pipeline.
