Well Integrity in the Production Phase - Application of a New Quantitative Operational Risk Model

Abstract

Almost all O&G companies have a well integrity management system based on a well failure model. Until now, they are mostly based on qualitative risk models with only very few claiming to use quantitative risk methods. The objective of this paper is to present a production well integrity managementsystem based on a different type of quantitative risk model. Traditional risk assessment methods were developed to be used in design stage. Therefore, they are not really adequate to manage operational risks during the production phase because they cannot take into account the operational history and the true current asset conditions during operation. Unlike such models, our quantitative risk/reliability model has been developed to be specifically used during the operational phase of a well. Therefore, it can accurately calculate the risk of an uncontrolled leak today and provide good estimates for the future evolution of this risk.This quantitative model has been served as the basis for the development of a web-based computational system which is now implemented in Petrobras and is an important part of the well integrity management system of that company. A descriptionis presented in this paper together with a simplified application to a subsea well.