For safe operation of wells, it is critical to maintain the integrity of production tubing. Integrity management in the wellbore needs to address a variety of factors including exposure to harsh environments, accessibility limitations on inspection tools, cost-optimization and need for production interruption for running the downhole inspection tools. Such scenarios make regular corrosion measurements difficult, and can result in a reactive approach to integrity management. Corrosion prediction software provides a solution to alleviate this issue.
Water-chemistry and flow parameters are key drivers for corrosion assessment. Generating these inputs for corrosion predictions using industry standard flow models requires significant expertise and is tedious which limits the frequency of assessments. Given the significant number of carbon steel tubulars in a giant offshore oil field in Abu Dhabi, the original process was too cumbersome resulting in only a select number of wells being modeled. To streamline the process, an automated application was developed which virtually integrates wellbore mapping, field data, multiphase flow physics, water-chemistry, and proprietary corrosion modeling software seamlessly.
The corrosion monitoring application has allowed for more frequent and timely corrosion assessments of a significant number of wells. The results to date include optimization of corrosion inhibitor (CI) usage during early production and to drive decisions for timely CI squeeze treatments. In addition to CI optimization, the high fidelity corrosion predictions have also driven preventative mitigations in wellbores with high wall loss leading to improved integrity. Application of this tool in conjunction with advancement in field data management enables a systematic approach in assessing tubular integrity status of wells in near real-time and predicting remaining life of tubulars.
Implementation of this unique, easy-to-use multi-disciplinary application assists in proactive management of integrity, avoids unnecessary workover, and enables cost saving by continued use of existing materials. The application was developed in a computational framework that allows quick integration of physics-based modeling tools for bespoke applications. Furthermore, it supports the development of corrosion monitoring plan, identification of wells with potentially high corrosion, and assists field engineers in defining inspection requirements to maintain well integrity.