Pipeline Routing Selection, The Most Important Aspect of Successful Pipeline Project

The definition of Pipeline itself, which this blog is all about and will be discussed a lot, based on API RP 1111, is piping that transports fluids between offshore production facilities or between a platform and a shore facility. Pipeline can transport both oil and gas and usually it is located on the seabed. Talking about pipeline infrastructure, it involves project that cost million of dollars because of the cost of pipeline fabrication, length of the pipeline, pipeline coatings, surveys, you name it. The first article in this blog will discuss about Pipeline Routing Selection, based on a few article I search on the internet.

Doug Evans, IPLOCA - Oil and gas pipeline routes are pivotal pieces of information upon which pipeline engineering depends. The route will define the pipeline size, terrain, soils, and engineering analysis requirements. Engineering assessment based upon agreed alignment selection criteria is an important part of a linear project. To be able to reach the best construction line and optimize its components, the phases – namely corridor, route, alignment, and construction line selection — should be studied in the given order.

Selecting the optimum route does not end with geotechnical challenges, as it also requires interactive coordination between the owner, the engineer, the regulator, the landowners, the construction contractor and a multitude of other project stakeholders and interested parties.

In mountainous terrain, such as in Turkey, geotechnical considerations are a significant aspect of pipeline route selection, as well as environmental and landowner concerns. The pipeline design must address geohazard mitigation for seismic areas and sections of the route which could be subject to landslides.

 Geo-political factors can also affect the route selection. Bringing Caspian Sea gas to Europe requires, among other pipelines, a new pipeline in Europe. A northern route requires a longer pipeline routed through environmentally sensitive areas, but this route supports future expansion of the pipeline system’s capacity. A southern route is shorter and reduces environmental concerns, but as this route also involves a marine crossing, the future expansion of the pipeline system is curtailed.

Primary selection factors

The detailed pipeline route selection is preceded by defining a broad area of search between the two fixed start and end points. That is, possible pipeline corridors. The route can then be filtered with consideration of public safety, pipeline integrity, environmental impact, consequences of escape of fluid, and based on social, economic, technical environmental grounds, constructability, land ownership, access, regulatory requirements and cost.

Economic, technical, environmental and safety considerations should be the primary factors governing the choice of pipeline routes. The shortest route might not be the most suitable, and physical obstacles, environmental constraints and other factors, such as locations of intermediate offtake points to end users along the pipeline route should be considered. Offtake points may dictate mainline routing so as to minimise the need or impact of the offtake lines or spurs. Many route constraints will have technical solutions (e.g. routing through flood plains), and each will have an associated cost.

Stages on determining the route

First, hold a project kick-off meeting where all the specifications of a project are discussed. Next, assemble a routing team to start the detailed process of developing a successful route. The routing team is usually comprised of an engineering project manager, a design engineer, and a representative of each field service group, including right of way, environmental, GIS, survey and construction. By involving every group that will ultimately be impacted by the pipeline route selection, everyone gets the opportunity to identify issues and problems with a proposed route and suggest routing changes that may mitigate these issues. This helps alleviate the need for re-routing of the pipeline further along in the project schedule, when changes can become more costly and timeconsuming. In the initial stages of route selection, most of the basic routing is done in the office by the GIS specialist using a web-based viewer that is customized for the specific project. This step requires the GIS specialist to download any publicly available information that could potentially impact the project disciplines.

This listing is a sample of the information that may be developed into data layers for eventual incorporation into the GIS viewer to use in preparing the desktop routing study. Once the data layers have been developed and added to the viewer, the routing team meets and begins the process of laying out the pipeline route.

Geo-hazards

Geo-hazards are widespread phenomena that are influenced by geological and environmental conditions and which involve both long-term and short-term processes. They range in size, magnitude and effect. Many geo-hazards are naturally occurring features and processes (e.g. landslides, debris flow, seismic activity, rock falls, etc.) but there are also many geo-hazards that are caused by anthropogenic processes (e.g. undermining, landfills, engineered fill, chemistry and contamination, etc.), and these too need to be taken into account during the pipeline routing exercise.

Geo-hazards are identified as geological, hydro-geological or geomorphological events that pose an immediate or potential risk that may lead to damage or uncontrolled risk. The type, nature, magnitude, extent and rate of geological processes and hazards directly influence pipeline route selection. Therefore, the process of early-stage terrain evaluation and the identification and assessment of geo-hazards and ground conditions are important as they can lead to extensive cost and time savings in the design and construction of a pipeline. 

The process enables the routing of the pipeline through the most suitable terrain, problem areas are identified, serious geo-hazards are avoided, where possible, and risks are minimised and mitigated. In addition, terrain evaluation is undertaken so that the need for expensive remedial measures or site restoration works is limited or prevented and the operability of the pipeline is safeguarded through a proper appreciation of the terrain conditions. By minimizing the risk of damage to the pipeline the risk to human safety is reduced.

Conclusion

In onshore and pipeline projects alike, the potential for catastrophe is always lurking close at hand to catch the naïve or complacent investor and contractor off-guard. However, when these challenges are successfully addressed, leaving a pipeline system with solid integrity and performance as well as satisfied investors, contractors and communities, projects can be very rewarding, both in financial terms as well as in the esteem accorded to all those involved.

Source:

http://www.oilandgastechnology.net/news/pipeline-route-selection-%E2%80%93-route-success
http://www.mustangeng.com/NewsandIndustryEvents/Publications/Publications/Pipeline%20Route%20Selection%20rev%2012-7-11.pdf