Since the drilling of the first oil well in Trinidad in 1857, through to the discovery of natural gas in 1971, and the emergence of most of the oil and gas facilities from 1991 onwards, technology, industry standards and best practices have been continuously evolving. Instrumentation and control systems tend to be heavily impacted by these changes because there are continuous developments in both hardware and software, and an increased focus in the areas of reliability, safety, and risk. This creates challenges in performing brownfield engineering and may introduce unexpected risks to project cost and schedule.
This paper examines examples based on actual design experiences and collective lessons learnt in the oil and gas industry in Trinidad and Tobago. The impact of industry trends on the execution of brownfield projects is assessed in three main categories: changes in instrumentation technology and advancements in control systems; the introduction and upgrade of standards such as functional safety codes IEC 61508 and IEC 61511 and HMI publications EEMUA 191 and 201; and changes in design philosophies resulting from updates to customer standards and best practices. Recommendations for addressing these challenges are provided.
Insights into the potential challenges that may be faced in performing instrumentation and control system upgrades can assist in mitigating potential setbacks, and facilitate better management of project scopes, and hence project cost and schedule. Finally, early investigation and front-end loading, particularly for brownfield projects involving instrumentation and control retrofits and upgrades, is identified as a solution to avoiding potential negative project impacts.
This paper presents an overview of the key challenges encountered in upgrading or modifying existing instrumentation and control systems on oil and gas facilities with a focus on the three areas highlighted above. Discussions are based on experiences within the local industry of Trinidad and Tobago, but can be applied to a global context.