Plant Reliability and Maintenance

Oil & Gas IQ

In the continuing difficult economic times, plant reliability is essential to ensure strong oil and gas production levels and prevent unplanned maintenance work.

Plant reliability also has its part to play in ensuring minimal damage to the environment is caused as a result of oil and gas operations. Reliability and safety go hand-in-hand, making sure that major incidents with the potential to affect the workforce and wider community occur as infrequently as possible.

Poor plant reliability also causes uncertainty among both investors and customers, ultimately impacting on the bottom line.

Speaking at an industry event in 2009, Sherman J Glass Jnr, president of Exxon Mobil refining and supply company, said: "We know that regardless of economic conditions we must continue to improve the safety and the reliability of operations, increase the efficiency of plants and steadily improve shareholder returns as well as invest in new technologies."

In many cases, the technical issues that lead to unplanned maintenance work are both costly and unavoidable. Understanding why these occur and when they are most likely to happen helps boost plant reliability.

High Priority

Sherman J Glass Jnr, president of Exxon Mobil refining and supply company, highlighted that risk assessments played an essential role in ensuring plant reliability.

"We have learned that while we operate in the start-up and shutdown mode less than 5 percent of the time, almost 40 percent of incidents occur during these "take-off and landing" periods," he explained.

Human factors can also have a profound impact on plant reliability, Glass highlighted.

"Operator care, operating inside safe operating envelopes, timely and thorough inspections and a detailed maintenance plan for each piece of equipment are just a few examples of the care and teamwork required to maximise up-time and more importantly minimise unnecessary distractions and risks," he said.

Exxon Mobil claims that standard operating systems deployed throughout its oil and gas network help boost reliability.

Fuel Variability

Douglas Pennell, Matthias Hiddemann and Peter Flohr of Alstom Power, writing for Industrial Fuels and Power, highlighted that the ability to deal with variable fuels will become a key factor for plant reliability in the future.

The experts said that gas turbines are likely to continue to play an important role in dealing with downtimes in renewable power supplies, thanks to their fast response time.

Changes to the gas market mean that liquefied natural gas is likely to be used as an alternative to pipeline gas in some scenarios.

"Power producers are looking for high-efficiency gas turbines with fast loading times that can meet environmental targets whilst maintaining the operational intensity to fuel variations. This fuel flexibility is thus a key requirement for future gas turbine plant reliability," they explained.

Subsea Oil and Gas Reliability

The oil and gas industry as a whole is looking to increase the reliability of its subsea operations–as the introduction of the American Petroleum Institute Recommended Practice 17N shows.

Aimed at helping the industry adopt reliability management systems, the principles should help increase the consistency of subsea operations.

Caroline M Roberts-Haritonov, Neil Robertson, and John E Strutt, Atkins Borea, writing for the 2009 Offshore Technology conference, said that the cost of repairing and maintaining unreliable subsea equipment is extremely costly, particularly in remote deepwater locations.

"Failures occurring during the early stages of production are particularly significant as these have the greatest adverse impact on project value, damaging the reputation of operators as well as that of their engineering contractors and suppliers," the experts explained.

They take the same view as Glass; in that many of the reliability issues could be addressed through risk assessment, particularly during the design stage where it is possible for such potential issues to be identified and managed.