Well Integrity is a vital aspect of well design, construction, operation, maintenance and abandonment. As put by SPDC, " all wells shall be designed, constructed, operated, maintained and abandoned in a manner that safeguards their integrity, minimize Health, Safety and Environmental risks and ensure their planned availability throughout their life-cycle". As a consequence of this policy, all wells are monitored to ensure their integrity is guaranteed at all times. By implication all wells that fall short of standards are secured or closed-in unless a short-term deviation or waiver is granted.
Well integrity problems may occur in producing and non-producing wells, especially older wells that were completed as per the prevailing completion standard of their completion dates. The completion standards have changed over time with respect to safety requirements (e.g. wells without top packers, wells without SCSSVs). There may also be some wells that meet current safety standards but still have some integrity-related problems (e.g. leaking packer or silted well slots-swamp locations).
Although, the necessity to enhance the integrity of wells is recognized, enhancement activities have been limited by past budget constraints. The identified activities often rank low in oil generating economics when compared with other projects within the portfolio competing for funds. It therefore became necessary to effectively manage the wide range of well integrity problems, by adopting a concept of ‘Well Integrity Management System’. In 2003 a dedicated team was set up to assemble a coherent process from the practices of the past and the present and inventorise work that needed to be carried out to ensure that well integrity issues are being adequately addressed.
This paper discusses the initiative by SPDC, Nigeria to put in place a Well Integrity Management System (WIMS) and successes so far.
Well integrity problems may occur in producing and non-producing wells, especially in older wells, which were completed as per the completion standard of earlier dates, but no longer fully, meet today's safety requirements (e.g. wells without top packers, wells without SCSSVs). There may also be some wells, which meet current safety standards but still have some integrity-related problems (e.g. leaking packer or silted slots).
To address the problem of well integrity, there is need for a corporate focus to ensure that all the wells meet a minimum integrity requirement. This together with other related requirements can be developed into a Well Integrity Management System (WIMS)- to ensure that each responsible operator aims to safeguard people and the environment as required by law.