Sunday, July 22, 2012
Posted by Ankit Chugh on 12:04 AM
The major cost of on-land pipeline will comprise of:
· Survey of Route
· Acquiring ROW
· Line Pipe
· Wrapping and Corrosion Coating
· Welding of Line Pipe
· Laying of Pipes
· Backfilling and Restoration
· Cathodic Protection by Impressed Current System
· Placement of Route markers
The major cost of subsea pipeline will comprise of:
· Line Pipe
· Concrete Coating for Weight Enhancement
· Cathodic protection by Sacrificial Anodes
· Laying of Pipes by Laybarge
· Welding of Line Pipes (partly on barge)
· Installation of Pipe risers (vertical line from the platform to sea bed)
Following figure gives proportion of cost components of subsea pipelines and on-land pipelines.
The cost of line pipe may be almost the same for the same quantity of fluid flow (except in case of subsea pipe line the thickness may be increased for stability and safety). The major difference between on-land pipeline and subsea pipeline is the cost of concrete coating, cathodic protection (sacrificial anode) is much costlier tha impressed current system), and the pipeline laying method.
The on-land pipeline is laid by side boom tractors, whereas for the subsea pipeline the laying is lay-barge. The rates for lay-barge are much higher than rates for side-boom tractors.