International Journal of Multidisciplinary Research and Growth Evaluation

Advances in Non-Intrusive Inspection of Pressure Vessels: Reducing Shutdown Frequency and OPEX in Oil and Gas Operations

Paul Chibuike Obetta¹, Nwakamma Ninduwezuor-Ehiobu², Henry Chukwuemeka Olisakwe³

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Abstract

Pressure vessels in upstream, midstream and downstream oil and gas facilities have traditionally been assessed through periodic internal visual inspection (IVI), a practice that requires the vessel to be isolated, depressurised, drained, purged, cleaned, scaffolded and entered under confined space permit. The cumulative cost of this preparation, combined with the deferred production associated with the shutdown window, represents one of the largest recurring line items in fixed equipment operating expenditure. Non-intrusive inspection (NII), in which the internal condition of a vessel is characterised entirely from the external surface using non-destructive examination (NDE), offers a route to replace or defer IVI without compromising integrity. This paper reviews the technical, procedural and economic advances in NII that consolidated around 2021, a period shaped by three converging pressures: the post-2020 collapse and partial recovery of hydrocarbon prices, the operational restrictions imposed by the COVID-19 pandemic on personnel mobilisation and confined space work, and the maturation of a dedicated recommended practice framework in the form of HOIS-RP-103 and its accompanying guidance notes. The review covers advances in ultrasonic corrosion mapping including full matrix capture and total focusing method reconstruction, pulsed eddy current profiling for corrosion under insulation, permanently installed thickness monitoring sensors, robotic and remotely operated deployment platforms, automated and digital radiography, and the analytics layer that converts dense NDE datasets into inspection decisions. A cost model is developed that decomposes the operating expenditure differential between IVI and NII, and an illustrative worked example for a representative offshore separator is presented. The analysis indicates that the dominant economic driver is rarely the inspection itself but the vessel preparation and deferred production it avoids, and that NII becomes financially compelling well before it becomes technically trivial. The paper closes by identifying the residual barriers to wider adoption: inspection qualification and probability of detection evidence, cladded and internally lined vessels, jurisdictional acceptance, competence assurance and the organisational challenge of managing inspection data at a scale that manual workflows were never designed to handle.  

Keywords: non-intrusive inspectionpressure vesselsrisk-based inspectioncorrosion mappingpermanently installed sensorsturnaround optimisationoperating expenditureasset integrity managementHOIS-RP-103API 510

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Licensed under CC BY 4.0.