The need for, and benefits of, a functional proactive pipeline integrity management system are now widely accepted across the industry. However, this has not always been the case and therefore many pipelines have been operated for long periods without the necessary proactive control measures in place. Developing and implementing a pipeline integrity management system for aged and degraded pipeline systems is often challenging, particularly where data is limited and/or the sheer extent of the problems make it difficult to know where to start. Nevertheless, it is likely to be the best and only means of regaining control of pipeline integrity and ensuring safe, reliable and efficient operation for the years to come.
Degradation of Ageing Assets
There are numerous time-dependent and time-independent threats that can adversely affect the integrity of a pipeline system. For aged systems, and particularly those for which historical controls have been lacking, it is the time-dependent threats (such as internal or external corrosion) that cause the most issues.
For example, the low water cut of produced fluids in a production gathering system during early field life may have been used as a basis for justifying the use of carbon steel flowlines without corrosion inhibition. Many integrity engineers will be familiar with the notion that past experience cannot be used to predict the future. However, long periods of operation without failure may provide an operator with a false sense of security regarding the condition of their pipelines. Unfortunately, a harsh lesson is to be learnt for such operators. In the example being considered, in lieu of appropriate controls being introduced, the first few and infrequent failures will inevitably be followed by an ever-increasing rate of failures as water cuts and unmitigated corrosion rates increase during later field life.
A similar lesson may also be learnt when unprotected carbon steel pipelines are laid in relatively benign conditions, where ground conditions are dry (e.g. deserts) and therefore the threat of external corrosion assumed to be low. However, even small corrosion rates may lead to loss of integrity given a long enough exposure period.
However, the problems are not necessarily limited to gathering systems or cases where corrosion control measures are not in place. Integrity issues may equally be encountered in an aged pipeline system that is apparently protected by cathodic protection and used to transfer what are believed to be non-corrosive export fluids (e.g. dry gas) without the right inspection or monitoring program to verify the that the relevant controls are effective.
In all of the above cases, the result is a loss of integrity that can be difficult to recover…but not impossible.
Recovering pipeline integrity once it has been lost is seldom a straightforward task and there is rarely a one-size-fits all solution. Furthermore, operators may be put off by the price of rectifying the issues. However, asking the question “How much is it going to cost to fix?” is perhaps the wrong question in this case. A more constructive approach is to ask, “How much it is going to cost if I don’t fix it?”. Only then may it be possible to find an appropriate and practical solution.
In any of the above examples, the first step is to develop an understanding of the underlying issues. Knowing that the integrity of a pipeline system has been lost due to an internal or external corrosion problem is not enough. In order to truly understand the problem, the integrity engineer must know the how, where, why, and when of these problems.
In the worst cases, pipeline replacement may be inevitable. However, by improving the understanding of the underlying issues, any subsequent replacement schedule can be optimised to address high risk areas and/or immediate threats to integrity and ensure that previous design or operational errors will not be repeated. Similarly, it may be possible to avoid or limit costly replacement scopes by implementing control measures to avoid further degradation to the point that replacement would otherwise be warranted. In either case, the operator benefits from an optimised solution and knowledge that root causes have been addressed to ensure the long-term integrity of their pipeline system.
AIE prides itself on supporting its clients by being able to think outside of the box when it comes to improving integrity management systems and standards, regardless of the age of the system. However, it is AIE’s unique experience working with operators of aged pipeline systems that sets it apart from its competitors. AIE works with their clients to establish SMART (specific, measurable, achievable, realistic, time-bound) objectives and find solutions that require a pragmatic approach than one that can perhaps be learnt or read from a textbook.
In addition to AIE’s highly qualified and experienced Pipeline Integrity Engineers, we utilise our industry leading in-house pipeline integrity management software, Veracity Pipeline, which allows operators to efficiently manage the integrity of their pipelines. The software provides operators with a user-friendly and systematic approach to pipeline RBI planning, which forms an integral part of pipeline integrity management.
For further inquiries on pipeline integrity management support, please contact our team today.