Pipeline corrosion - Pt 1 (Introduction)

As worldwide demand for oil and gas continues to increase, it remains vitally
important that supplies are able to reach the market both quickly and efficiently,
for this, pipelines are vital in creating a significant transportation network - but
therein lies a totally different problem.

Today, new pipeline projects are being fully welcomed by the industry, but in-line with this existing pipelines need to be maintained so that they stay fully operational and that pipeline corrosion doesn't become an issue. Nonetheless, the oil industry's annual corrosion costs are estimated at about US$15 billion.

Some pipelines deteriorate slowly, and in certain cases pipeline life has been reliably targeted at 70 years or more. Other pipelines have been built which have exhausted their useful life after ONE year of operation, according to Corrosion Doctors.

Accurately tracking changes in corrosion rates is a serious challenge for gas pipeline operators. Pipeline regulators require operators to demonstrate that corrosion rates are as low as two mils/yr. or less to ensure safe operation. Should the measured corrosion rate exceed two mils/yr., operators are required to take actions to mitigate the corrosion or effect repairs.

While many approved technologies (e.g., corrosion coupons and electrical resistance (ER) probes) are available for measuring corrosion, most of these technologies measure the corrosivity of the gas rather than the changes in the pipeline wall. Because these methods infer the rate of corrosion of the pipeline indirectly, the accuracy of the measurements can be influenced by numerous factors.