TPi March 2023

Monitoring subsea valve and pipeline condition more efficiently using advanced digital technology By Ivar Stange, senior engineer, 4Subsea

Subsea valves can face several detrimental issues over the course of their lifespan, and monitoring their condition in an effective, holistic and transparent manner can be challenging. Traditionally, engineers have used spreadsheets and static PDF logs to track and manage valve status and plan operations. However, there might be hundreds, or sometimes thousands, of valves on a subsea field. In addition, with a high degree of manual processes, managing the valve status process is time consuming and always a risk of human error, causing incorrect information. Typically, each valve register is documented in a single spreadsheet or in a document library. This has a master owner, but editable versions can lose their way when passed from pipeline and valve stakeholder to stakeholder. As a result, an accurate description of the condition of the valve may be lost. Such a workflow is fragile, therefore strict and detailed procedures must be maintained to ensure the documentation is always updated to provide required and correct information across all interested parties. This traditional way of handling the valve data can have huge implications on the engineer’s focus. While they would like to analyse the system and the readiness of any component, their focus is instead targeted on stewardship of data and being meticulous about not making any mistakes when gathering information from multiple sources. By digitising the valve condition monitoring process, 4Subsea, a leading provider of technology and services that help operators optimise energy production from subsea oil & gas fields and offshore wind farms, helps eliminate many of the pitfalls in the traditional process by providing stakeholders with easy and secure access to correct and relevant data by removing any discrepancies caused by manual work. Valve condition monitoring A subsea field in operation may have hundreds to thousands of mechanical valves operated by ROVs or divers. These valves are used to control the flow of fluid and can also act as crucial safety barriers to avoiding unwanted spills of hydrocarbons into the environment. Therefore, during subsea intervention work, replacements, or new tie-ins, it is imperative that they are correctly positioned and fit for purpose so that the barriers remain intact to ensure safe operations. While age is a general issue, how often valves are operated and the torque applied, are variables that also affect operationality. Mitigating actions can be taken to ensure that the applied torque necessary for a valve to operate does not exceed design limits and consequently damages the system. All valves have design limits, including operational

Figure 1: Valve system

or maximum torque, that they should not exceed before potentially being broken. Being able to track the critical developments over time, from when the valve was installed, will allow engineers to predict when increasing torque can damage or break the valve. In addition, condition monitoring allows maintenance to take place in due time or engineers to accurately consider whether to open or close the valve as it may be susceptible to failure mode. Another fact worth considering is the age of the valve, not just in terms of years but also in usage. While some may be turned on to one position when commissioned and not operated for several years – others are constantly being opened and closed and undertaking new operations. Workflow challenge Typically, the manual workflow performed today is that engineers report the valve status in separate text logs. Examples of statuses are whether they are open or closed, the torque being applied and the number of turns. Unfortunately, this input can be non-structured making it challenging to analyse and track history. Often, parameters may not even be documented, leaving engineers at a loss as they search through multiple PDF files and emails. The solution The ValveTrack solution is an easy-to-use digital service. The solution captures all relevant information, such as attribute data, operational history, documents and pictures, for the lifetime of the valves from the design to the last intervention



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