This article aims to present the evolution of well design and well integrity monitoring throughout their life cycle and life extension analysis. The motivation comes from the need to make a decision to extend the life of wells, accounting both for Green and Brown Fields. PETROBRAS design practices were updated to meet the Well Integrity National Regulatory requirements and to support the life extension analysis.
In order to assess the well integrity during production lifetime, a Digital Twin of the well was developed and is capable of modelling the physics of permanent and transient fluid flow and corresponding behavior of trapped annuli with thermo-structural coupling to the mechanical structure. Also, as part of the monitoring process, additional information will be provided by new sensors to be installed in the A and B annuli, aiming to improve monitoring capability.
This paper will present the results of the new well design and life extension analysis practices for retrofit projects. Besides that, a discussion on new challenging scenarios faced by the company is included. The well integrity case study of a deep-water field in Brazilian offshore, through a real time digital twin approach, will highlight the main technological solutions developed to ensure well operation within the envelope during its lifetime. The adoption of this strategy allows the optimization of procedures with the goal of maximizing production or injection rates, still according to safety requirements. The availability of additional annuli sensors can improve the system capability.
With the well integrity surveillance digital twin, PETROBRAS successfully implemented a unique monitoring integrity system for offshore production units in Brazil, increasing the understanding of the well structure behavior and, consequentially, the assets operational safety during its lifetime. In addition, this initiative aims to push the industry towards the development of wet X-mas tree according to API RP 17V requirements.