Pipeline decommissioning, or pipeline abandonment programmes are extensively used for pipelines, especially in the oil and gas industries.
Pipelines or power cables may be decommissioned in place if they do not interfere with navigation or commercial fishing operations or pose an environmental hazard. However, if the BOEMRE rules that it is a hazard during the technical and environmental review during the permitting process, it must be removed. The first step to pipeline decommissioning in place requires a flushing it with water followed by disconnecting it from the platform and filling it with seawater. The open end is plugged an buried 3 ft below the seafloor and covered with concrete.
Within the industry, the North Sea and Gulf of Mexico are likely to experience a great deal of pipeline decommissioning and abandonment within the next 30 years. The North Sea Offshore Decommissioning work will see 470 pipelines wholly or partially removed. New legislation within the Gulf of Mexico has also forced the industry to put in place decommissioning programmes.
To ensure proper site clearance, operators need to follow a four-step site clearance procedure.
- Pre-decommissioning survey maps the location and quantity of debris, pipelines, power cables, and natural marine environments.
- Post decommissioning survey identifies debris left behind during the removal process and notes any environmental damage
- ROVs and divers target are deployed to further identify and remove any debris that could interfere with other uses of the area.
- Test trawling verifies that the area is free of any potential obstructions.
Sources:
- http://www.inpipeproducts.com/pipeline-decommissioning/
- http://www.rigzone.com/training/insight.asp?i_id=354
No comments:
Post a Comment