The loads put on pipelines and wells by carbon dioxide are very different to those involved in the production and transport of oil and natural gas. As a result, relevant regulations must be reviewed in order to ensure that the appropriate amendments are made with respect to CCTS developments.
Establishing a well-adapted regulatory framework will allow the PSA to facilitate a potentially important response to the climate issue.
Carbon dioxide is a major component of flue gases, and cannot easily be removed by installing a filter. It must be captured with the aid of a large and advanced industrial plant.
Such installations also pose safety and working environment hazards, and mean that oil companies must deal with new types of risks. Parts of the technology required for CCTS projects have already been tested, reports Torleif Husebø, discipline manager for process integrity at the PSA.
Other components need to be developed or tailored to new applications. “Today’s regulations for HSE in the petroleum sector require a systematic approach to all types of risks in the activity,” he observes.
“We’re nevertheless reviewing relevant sections of the regulations with their associated guidelines to ensure that the necessary supplements and amendments are adopted.
“Although suitable regulations are an important foundation, they provide no guarantee in themselves that the activity is acceptable. Good knowledge, procedures and attitudes in the industry are at least as important.”
“It’s well known that carbon dioxide can pose a risk to people,” Mr Husebø notes. “If a leak enhances the carbon concentration in the air, it can cause serious respiratory problems which could at worst be lifethreatening.
”These dangers are very familiar in particular disciplines, such as diving, he points out.
But when large new groups of workers become exposed to them, knowledge must be enhanced and the risk well managed. “Technical safety will also be challenged,” Mr Husebø says.
“Efficient transport of carbon dioxide and its injection below ground require it to be in liquid or supercritical form.
“That in turn demands gas compression. Handling chemicals under high pressure represents a well-known safety challenge in the petroleum business.
“But carbon dioxide has very different properties from natural gas, and the mechanisms in a possible accident would differ. That underlines the need for learning by both industry and government."
Pumping carbon dioxide into a sub-surface formation presents new challenges in understanding geological conditions, adds principal engineer Hilde-Karin Østnes at the PSA. Official expertise in this area rests primarily with the Norwegian Petroleum Directorate (NPD), but supervising the protection of well integrity is an important priority for the PSA.
That applies not only to the actual design of injection wells, but also to challenges associated with existing wells in a formation to be used for carbon injection.
Good communication with the NPD is accordingly both important and natural in order to ensure sound interaction between well safety and reservoir properties.
“Collaboration between us and the NPD rests on long experience of exploration for and production of oil and gas,” explains Ms Østnes, who works in the drilling and well technology discipline.
“Some experience has been gained with undesirable incidents, not least related to water injection, which could have certain similarities with the challenges presented by carbon injection.
“It’s important that both the industry and the authorities apply these lessons and all other available knowledge to ensure safe underground carbon storage in a time frame of many hundreds, perhaps thousands of years."