Digital Twin for Well Integrity with Real Time Surveillance

Abstract

During the production phase of the PW1 well, an unintentional operation depressurized the annulus A below its design limit, causing a progressive casing collapse from the surface casing to the tubing string, resulting in a well failure and a subsequent an abandonment operation. This event was detailed in a previous publication (Campos et al., 2019). After a detailed investigation of the events that drove the well failure and using casing design software to simulate the well behavior with the historical time series data, it was possible to identify the exact moment of the casings collapse through mathematical modelling. Based on that, considering innovation as critical success factor (Rocha, 2012), PETROBRAS started an R&D project to evaluate, in real time, critical integrity events during production phase. The approach proposed consists on the integration of a transient fluid flow model (Bonizzi, 2003) and (Bonizzi, Andreussi and Banerjee, 2009) with a structural model (AraÚjo et al., 2019) of the well and loads being calculúated in real time as a function of the production data (PDG’s, X-TREE and Topside). The process described was named as Well Integrity Surveillance (WIS) and its being designed to work 24/7 in a collaborative environment, integrating well handover information, inspections and intervention reports, production data and flow modeling. The objective of this paper is to present the well integrity case study of a deep-water field in the Brazilian coast, through a real time digital twin approach, highlighting the main technological solutions, developed to ensure the assets operational envelope, during its lifetime. With the well integrity surveillance digital twin, PETROBRAS successfully implemented a pilot project on three offshore production units in Brazil, increasing the knowledge of the well structural behavior and consequentially the assets operational safety during its lifetime.