Comprehensive reliability-based well integrity analysis: application to worst case discharge (WCD) scenario

Resumo

The global increase in energy demand, combined with the availability of hydrocarbons, positions oil and gas among the main non-renewable sources in the world's energy matrix. In the scope of well design, ensuring their structural integrity under increasingly severe conditions, especially in deep and ultra-deep water, has become a critical factor for the oil and gas industry. Consequently, there has been an investment in modeling extreme environmental scenarios found in challenging wells to ensure their integrity throughout their lifecycle. This work proposes a new methodology for probabilistic analysis of structural integrity during the construction and operation phases of wells, taking into account the uncertainties associated with variables related to the behavior of tubulars, cement sheath, formation, and applied loads . It aims to analyze well integrity through safety barrier failure events in a scenario of severe blowout known as Worst Case Discharge (WCD), using structural reliability theory. The calculation of failure probability will be carried out using the First Order Reliability Method (FORM) and Monte Carlo simulation. It is understood that the proposed methodology can be applied in the design and monitoring stages of wells, contributing to decision-making process.