Abstract
The importance of pipelines can be secondary to none when being vital for the development of a nation and its people. However, like any other project, a pipeline project also has impact on the environment during the installation as well as operation phases. One of the most challenging tasks is the containment of leakage of the fluid in case of damage to the liquid hydrocarbon pipeline. The leakage of hydrocarbon liquid can have detrimental effect on environment especially when it happens at a river crossing. Sectionalizing valve (SV) stations are provided to divide the entire pipeline into sections to minimize the loss of hydrocarbon and limit the damage caused to local environment and its inhabitants. Location of these sectionalizing valve stations is very crucial with regard to the all-weather access and minimal environmental impact in case of leakage. While for liquid hydrocarbons other than LPG the maximum distance of 50 km between successive SV stations is clearly specified in various applicable codes and standards, there is statutory requirement to install Sectionalizing valves (or Mainline block valves) on both sides of major river crossings and public water supply reservoirs as close as possible near the upstream and downstream bank of the river and public water supply reservoirs for isolation of these portions of the pipeline. Although this requirement is necessary for minimizing the environmental impact, a lot of cost is incurred in providing an SV station.
The present case study discusses in detail the methodology adopted for selection of locations to provide SV stations of a 26 inch size Crude oil pipeline of a reputed energy major. Over 200 river crossings are encountered in the route of this pipeline. The methodology for location selection of SV stations intends to optimize number of SV stations by identifying the major river crossings and providing SV stations on their upstream and downstream sides. This involves the usage of modern tool of historical satellite imagery along with the survey data/information of the pipeline route.
