Oil & gas pipelines are the primary method to transfer products from refinery to final consumer. Extensive network of steel tubes move hydrocarbons at high speed between multiple locations in the country and other parts of the world on a daily basis.
All commercial activities come to an end and decommissioning is an essential phase, every oil & gas operator must plan well ahead of time to ensure cost effectiveness and compliance with applicable regulations.
Pipeline decommissioning is termination of oil & gas transport through a pipeline at the end of the economic life of the process. It requires planning of manpower and resources that needs to be used along with the land regulations specified by authorities.
Pipeline operators and owners are responsible for operating and retiring their pipelines in a manner that respects the health and safety of citizens in the immediate locality. The Federal Energy Regulatory Commission (FERC) is the body responsible for regulating pipeline usage and decommissioning in the U.S.
Before decommissioning a line, a comprehensive engineering and environmental impact assessment are carried out by the operating company. The regulatory authority for the area then approves a suitable decommissioning procedure based on the results of the evaluation.
The pipeline decommissioning process could be either pipeline removal or abandonment.
Types of Pipeline decommissioning
Pipeline decommissioning in oil & gas industry depends on pipeline type, location, fluid type, etc. In the oil & gas industries following types of pipes are decommissioned
- Onshore Pipeline
- Offshore Pipeline
- Subsea Pipeline
On shore Pipeline Decommissioning
Here the retirement of land based pipelines above or below the surface of the earth is carried on. Its process typically involves
- Flush out any remaining oil & gas from pipeline
- Cleaning pipelines with specially made devices like PIGS
- Physical separation of Pipeline from supply
- Recovery of newly decommissioned pipe
Subsea Pipeline Decommissioning
This involves retiring the pipelines located in very deep water wells and isolated areas.
Ways to decommission are as follows
- Preservation in place for future use
- Pipeline Recovery(Expensive Process)
- In-Situ Pipeline Retirement procedure
In the U.S., subsea decommission is covered under the CFR (Code of Federal Regulation) Part 250, Sub-part Q(12) and administered by the Bureau of Safety and Environmental Enforcement (BSEE).
For decommissioning efforts in ultra-deepwater wells and remote locations, health and safety standards are of paramount importance.