Development of NDT Inspection Tool for Subsea Non-Insulated Flexible Pipes to Support SCC-CO2 Integrity Management for Brazilian Deep Offshore Application

Abstract Flexible pipes are critical components in offshore oil and gas production that enable the safe transportation of hydrocarbons between subsea facilities and surface vessels or production platforms. Subsea pipes require periodic inspection to ensure their fitness for purpose, once this practice guarantees the safety of people, environment and assets during the operation of an oil and gas production facility. It is particularly critical when it comes to deep offshore pre-salt fields in Brazil due to the risk of stress corrosion cracking induced by CO2 (SCC-CO2) phenomenon, which has been a challenge for Brazilian oil and gas industry. The annulus, an important cavity inside the pipe structure, plays a vital role in maintaining the integrity of the pipe by providing insulation, absorbing pressure fluctuations and preventing corrosion of the structural wires. The presence of breaches in the outer casing of the annulus can cause flooding, thus compromising these functions, leading to moisture ingress, corrosion and potential structural failure. An early detection of annulus flooding is therefore essential to assess the integrity and operational safety of flexible pipes. This proactive approach minimizes the risk of catastrophic failure, optimizes maintenance schedules and increases pipe lifetime, ensuring safe and efficient offshore operations. The importance of detecting annulus flooding is not only related to the protection of assets, but it also refers to the protection of personnel and environment from potential hazards. TotalEnergies EP Brazil and InnetiQs, in a joint project, developed a new edge tool called FADS (Flooded Annulus Detection System), a reliable solution for the detection of flexible pipe annulus flooding in subsea operations to support annulus inspection in light of the damage mechanism due to SCC-CO2. Moreover, it was further on developed to be applied as quality control support for the inspection of flexible pipe spare units in onshore yard conditions. This paper aims at reporting the first on-site successful trials in Brazilian waters carried out with FADS tool, focusing on the type of results and technology advantages that FADS brought to the industry in order to cope with existing gaps.