Construction of Pipeline

Designing and constructing a pipeline is a major undertaking, requiring a wide variety of engineering and construction skills. A large pipeline the operator would have the internal resources (both trained and experienced manpower and equipment) to undertake all phases of pipeline construction, it is more likely that virtually all of the major phases of construction will be contracted out to companies possessing the necessary expertise and capacities to complete the task. While that guarantees the critical requirements of the pipeline construction will be met, it also introduces the need to control logistics to ensure that all contractor activities are coordinated and not mutually exclusive of one another. Construction can take place because pipeline construction equipment is distributed along the pipeline route in a moving assembly line in which only one major item of construction equipment is normally needed at any one point of time. The distance along the pipeline over which this equipment is deployed is relatively shorter and less than a mile, but there may be several sets of construction equipment operational along the pipeline route at any given time. The complete set of equipment — for ditching, welding, coating, lowering in, and backfilling are called spreads. A single pipeline may be built using several spreads, reducing the overall construction period, but also increasing the number of people and secondary resources required to support them. Large pipeline projects can also be divided into two or more segments, and different construction contractors may be used to install each segment. Various construction activities also take place simultaneously on a number of segments. Each of these contractors may field several spreads to build a segment. The actual installation of the pipeline includes these major steps: 

1. clearing the ROW as needed.

2. Ditching.

3. Stringing pipe joints along the ROW.

4. Welding the pipe joints together.

5. Applying a coating and wrapping the exterior of the pipe (except for the portions of the pipe at each end, which is sometimes coated before being delivered to the job site).

6. Lowering the pipeline into the ditch.

7. Backfilling the ditch.

8. Testing the line for leaks.

9. Cleanup and drying the pipeline after testing to prepare it for operation.

10. Reclaiming impacted environmental areas.