Regulatory Intelligence
When can zonal abandonment be treated as routine instead of non-routine?
Category:
Well Abandonment
Research Basis
Archive Period
2017-2022
Records Reviewed
6
Primary Topics
Directive 020; Well Abandonment; Non-Routine Abandonment; Variance Requests; Zonal Abandonment; Closure Programs
Current Reference
AER Directive 020
Common Question
When can zonal abandonment be treated as routine instead of non-routine?
Archive Findings
The archive shows that the routine versus non-routine distinction can turn on the technical details of the proposed isolation. In the zonal abandonment correspondence, the key issue was whether the cement plug would extend sufficiently above and below the combined perforated interval. The archived response indicated that if the cement plug extended 15 metres above and 15 metres below the combined interval, accounting for squeezed volume and shrinkage during curing, the work could be considered routine. The same record also identified the practical consequence if the interval was not adequately covered: additional cement could be required, a bridge plug could be added, or the operator may need to proceed through a non-routine abandonment request. This is a stronger lesson than simply saying zonal abandonment depends on the well. The archive shows that the decision can depend on whether the proposed isolation physically satisfies the abandonment requirement for the zones being isolated.
Engineering Insight
The engineering lesson is that zonal abandonment planning should begin with the interval and isolation objective. Engineers should compare the perforated intervals, proposed cement placement, curing/shrinkage considerations, and mechanical barriers before deciding whether the work is routine or requires a non-routine submission. A small design detail can change the regulatory pathway. If the plug does not provide the required isolation coverage, the issue may not be solved by explanation alone; the program may need to be modified, or a non-routine request may be required.
Current Guidance
Current zonal abandonment and non-routine abandonment requirements should be reviewed against the current version of AER Directive 020. Historical correspondence provides useful context for how isolation coverage was evaluated, but current Directive 020 requirements always govern.