Published on 16 Sep 2016 by Tadd Pham
Pipelines should be decommissioned and abandoned (by removal or abandonment-in-place) in accordance with applicable national, regional and local regulations and requirements, concession terms and contractual agreements, and permit requirements. In the case of conflict, the more stringent requirement should apply, unless an exception procedure is implemented to approve and document the deviation. Pipelines should be abandoned using generally accepted engineering and construction practices, proven industry processes, methods, and procedures, as well as with due consideration for health, the environment and safety, sustainability and reuse, and Company reputation, both during abandonment activities and considering future land or sea use.
- All onshore pipelines on the surface, and in depths shallower than 200 feet (below mean sea level) should be removed unless buried to an acceptable depth below the surface or seabed suitable for abandonment-in-place. If abandoned in place, pipeline stability should be assured over the long term.
- If a pipeline (or group of similar pipelines) is a candidate to be abandoned-in-place, a risk assessment should be performed in the early phase of abandonment planning to determine whether the pipeline should be removed or abandoned-in-place. The risk assessment should be consistent with the HSE risk management process and evaluate HSE, business, social, and reputational risk. The risk assessment should evaluate relevant criteria (such as potential public exposure, future land or sea uses, e.g. fishing or shipping, regulatory requirements, rights-of-way, landowner agreements, and technical feasibility) and the results documented and considered in making the removal versus abandonment-in-place decision. If abandonment-in-place is selected, appropriate mitigations should be implemented based on the risk assessment results.
- A pipeline should not be removed or abandoned in place without first being cleaned to an acceptable standard, which is normally achieved by pigging and then flushing or purging the pipeline of hazardous liquids and gases, including hydrocarbons or other materials. Materials flushed or purged from liquid pipelines must be captured and sent for proper reuse or disposal. Gaseous materials may be permitted to be vented to atmosphere or to a control device if not purged to an active pipeline segment or otherwise captured for reuse. Regulatory approvals and permits may be required for the venting of gaseous materials or routing to a control device. The HSE department should be consulted for guidance on acceptable criteria and requirements for disposal or discharge of liquids and gases.
- An unidentified pipeline should not be cut, sheared, drilled or welded upon. If unsure, check all related documentation (e.g. drawings, surveys, maps, regulatory records), interview operations staff (current and previous) and discuss with other operators that have pipelines in the vicinity to positively identify the pipeline in question. If questions persist, perform additional surveys and trace the line to its source (e.g. with sonar or divers) to positively identify the pipeline.
- Hazardous wastes should be properly disposed of at an approved hazardous waste facility. Decommissioned materials containing hazardous wastes should either be sent to a decontamination facility (where the hazardous wastes should be removed and properly disposed of at an approved hazardous waste facility) or disposed of at an approved hazardous waste facility.
- Environmental site assessment, remediation, and restoration should be coordinated with the pipeline abandonment work. Environmental Subject Matter Experts should be engaged during project planning and execution phases to determine if environmental assessment, remediation, and/or restoration activities are required. Onshore, coastal and offshore areas (land or seabed surfaces) should be left in a state suitable for subsequent use, without being a hazard to users of the areas.
- Pipeline abandonment projects should define minimum technical capability and experience expectations within contract plans and bid/tender packages as needed to assure workforce competency for work execution.
- Items to consider in early-phase project framing and alternative development include pipeline abandonment-in-place versus removal, timing of work activities, regulatory requirements, HSE issues and risks, financial issues and risks, disposal requirements, and stakeholder requirements or expectations. Each region where Company operates may have unique requirements, and the abandonment plan must be suited to the overall goals of both Company and external stakeholders.
- Site visits and inspections should be undertaken during the planning and engineering phases to build an understanding of the site and establish detailed site-specific information, to identify issues that may need to be addressed in site-specific abandonment procedures or incorporated into analytical models, and to develop detailed abandonment execution plans and removal procedures.
- The site visit and inspection should include an assessment of the condition of the pipeline, associated facilities and infrastructure, and site conditions. The visit should include inspection, testing, and documentation of the presence of hazardous
materials. Typical materials that might be encountered at pipelines and associated facilities (which may or may not be hazardous) include the following:
- Naturally occurring radioactive material (NORM)
- Paint and lead-based paint
- Polychlorinated biphenyls (PCBs)
- Chemicals of unknown composition
- Containers of unknown material
- A basis of estimate document should be developed for each pipeline abandonment project to guide the development of cost estimates. Where possible, individual pipeline abandonment projects may be grouped to form a campaign and thereby provide more leverage in dealing with contractors for securing equipment and reducing costs, and in gaining efficiencies through process repetition.
- The following items should be considered and incorporated as appropriate during early phase project development and planning.
- Regulatory requirements governing pipeline abandonment vary by country, and even within various regulatory jurisdictions within a country. Therefore national, regional and local regulations, concession terms and contractual agreements, and permit requirements should be reviewed, as well as government decrees in place at the time of project development and planning, including those that define hazardous wastes and hazardous waste management requirements. Permits are generally required where a regulatory framework exists, and some permitting processes may require a public comment period.
- A Transportation and Waste Management Plan should be developed that covers the handling, storage, transport and disposal of all wastes, including the recycling of scrap materials and the disposal of wastes, both hazardous and nonhazardous materials.
- Pipeline abandonment risks should be assessed using the HSE Risk Management process to evaluate HSE, business, social, and reputational risk. Risk registers that include HSE, project execution, and Company reputational risk factors should be developed and appropriate risk mitigation plans developed and managed. Assets with similar HSE, reputational, and project execution risks may be grouped together to facilitate assessment.