Bonga oil producer wells are capable of delivering high rates in excess of 20 Mbopd; thus, any breach of well safety critical barriers could potentially lead to significant people asset and environmental damages. In addition, deferment caused by well integrity would also significantly impact production. Therefore, well integrity management remains an integral part of Shell's "Must Wins" and the Bonga team is focused on ensuring that we can demonstrate that the Bonga wells remain "safe and healthy" while delivering against production targets. One of the key challenges faced in the deepwater environment is the prohibitive high cost of rig intervention for diagnosis and remediation of well equipment failures; hence the well integrity management approach in the Bonga field places a lot of emphasis on use of alarm settings to operate wells within defined operating envelopes; proactive monitoring of the well operating parameters and consistent high compliance on preventive maintenance. This has resulted in the early detection of well integrity issues and minimal shut-in periods of wells for well integrity related failures. Also, innovative and cost effective methods of integrity repairs using an ROV deployed by the field intervention vessel have been implemented in the Bonga field. This article describes the application of Well Integrity Management in the Bonga deepwater environment and highlights some of the challenges and lessons learned in safeguarding the integrity of deepwater wells through the operational phase.

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractProduction from the deepwater Bonga turbidite reservoirs was started in November 2005. As with all waterflood and Enhanced Oil Recovery schemes, 'world-class' Well and Reservoir Management (WRM) is the foundation of a successful project. A comprehensive WRM plan was defined for Bonga very early in the project, and its implementation from start-up has demonstrated tremendous value.More than 220 MMstb have been produced as of March 2009 from 13 subsea producers, and reservoir pressures have been maintained by water injection from the start of production in 13 subsea high rate water injectors, allowing high field production rates to be sustained. Well and reservoir performance data obtained during the first three years of production, and information from 4 D seismic shot in early 2008 are now used to optimize the planning and drilling of additional wells as part of the Phase 2 development drilling project. Bonga is a 'brownfield' that is not immune to normal well and asset integrity issues, and declines in well injectivity and productivity. Ability to respond swiftly to these issues is part of the Bonga WRM Plan. This paper presents key elements of successful WRM in Bonga. These include people factor and cross discipline integration, Smart Fields ® capability, 'live' WRM Plan and monitoring, good understanding of subsurface, application of integrated production modelling, intervention readiness and effective well integrity management. The paper concludes on key learnings applicable to future deepwater waterflood projects.