Corrosion is a hugely significant issue to the oil and gas industry. This is especially true in marginal development projects where tight profit margins are in play and an unplanned failure in a key component or system can rapidly lead to the premature closure of the associated well, or even field, and a reduction in returns on investment to operators and shareholders. Here, Dr Cameron Stewart, Upstream Technical Manager for the Energy Institute (El), introduces the work underway at the El to provide a framework for a successful corrosion management strategy to address this critical issue.
Corrosion issues are not new, with various references across history, including references in the works of the prolific classical writer Pliny (around AD50), and indeed, as evidenced in the Latin root of the word 'corrosion' itself, from corrodere meaning 'to gnaw away' or 'gnaw to pieces' (comparing the phenomenon to the observed action of rats).
While teaching corrosion engineering and management many years ago at a leading UK university, I used to draw upon the Douglas Adams 'classic', the Hitchhiker's guide to the galaxy, to start my series of classes. I employed a modified quote from the book that went like this: 'Corrosion/Space is big, really big. You may think it's a long way to the corner shop but that's peanuts compared to Corrosion/Space...'.1 I would then put the quote in the context of the various national surveys that take place from time to time, starting with the UK's Hoar Committee and associated report in 1971 which gave the impact of corrosion in financial terms of 3-4% of GDP.2 Similarly, Fontana starts his 1987 book Corrosion engineering with a similar discussion on the costs of corrosion, but on the US side of the pond, with estimates in the range of $8bn to $126bn in annual costs, taking $30bn as a 'realistic' figure.3 He goes on to refer to an article whereby the cost of corrosion to oil and gas producers alone in the US was estimated at nearly $2bn/y (Wall Street Journal, 1981) while warning of expectations for costs to rise as the industry moved into deeper waters and harsher environments - which of course is now common place worldwide and with those associated increased costs of corrosion. More recent surveys usually continue to quote the cost of corrosion at similar levels of %GDP.
Big numbers indeed, which translates to big technical challenges and big associated potential rewards. This would at first glance seem like an easy case to argue to senior managers within any organisation for suitable budgets to ensure a successful management strategy is delivered. Unfortunately, corrosion as an entity tends to spread its impact across a number of different operations such that it affects virtually everything without actually being identifiable as a separate line-item on any balance sheet. This is true on a national level -there's no UK Department of Corrosion for example - despite that 3-4% of GDP figure, and on a much more personal level, within the annual costs of corrosion and degradation associated with running the average domestic home and family car.
But as Adams' classic book comforts us - 'don't panic' - corrosion can be managed to head off unexpected failures and unplanned down time.
The Energy Institute (El), working with its Technical Partners and other key stakeholders including the regulator (HSE in this case), and industry body Oil & Gas UK, came together in 2007/2008 to form a new Corrosion Management Working Group (since promoted to a full El Committee, CMC) to work together towards agreeing and setting out good practice guidelines for the industry. This resulted in a framework (see Figure 1) for developing an efficient company corrosion management strategy to assist with maintaining process plant and structural integrity for the petroleum industry, in the form of a first edition of the El's Guidance for corrosion management in oil and gas production and processing in 2008, which is referred to extensively both in UK and worldwide offshore operations.