The Integration of Intelligent Well Systems into Sand Control Completions for Selective Reservoir Flow Control in Brazil's Deepwater

Abstract

This paper describes the integration of intelligent well system technology into a conventional, open hole sandface completion for the purpose of selective flow control in a deepwater reservoir. In deepwater subsea applications, the ability to remotely control the inflow of water can eliminate costly rig intervention while extending well life and increasing recoverable reserves. The planning, testing and installation of these technologies will be detailed in this paper. Deepwater Brazil continues to be a region where technology which addresses inherent cost and risk can favorably impact financial performance. The horizontal gravel packed completion was introduced in deepwater subsea Brazil in 1998. To date, over 67 successful subsea horizontal gravel packs have been installed in both production and injection wells. To further enhance deepwater financial performance offshore Brazil, installation of a Level 6 multilateral well in the Campos Basin occurred in 1999. Given the demonstrated success of open-hole horizontal gravel packing, and the fact that this technology is now relatively mature, additional completion capability in the way of effective, selective zonal isolation has become desirable. Addressing this challenge is the application of diverter valve technology. This technology has been successfully used in 8 subsea wells in the Campos Basin during the year 2001. Combined, zonal sandface isolation and the long reach of horizontal wells provide operators with the ability to selectively drain a reservoir(s) and move the development cost per barrel oil equivalent (BOE) downward. The fully electric intelligent well system consisting of 3–1/2" and 5–1/2" smart selective flow control devices was deployed on land in the Mossoro Field. The purpose of the installation was to prove the technology before transferring the application into the deepwater subsea environment. These valves were operated remotely from the office location. After months of successful actuation and data acquisition, the system was pulled and prepared for installation into a deepwater subsea well. During the land based well test, it was deemed necessary to modify the volumes of data stored. Software modifications were made to optimize the rate of data storage. In order to integrate the Intelligent Well System into the sand control completion, a process of optimization was necessary to meet well construction and operational requirements. This process was inclusive of well path design to reach the targeted well location while controlling the dogleg severity to allow placement of the intelligent well system It included completion design to achieve selective flow control and minimize operational risk during installation. This is the first application of an all electric, remotely operated intelligent well system integrated into a sandface completion for the purpose of reservoir production management. Introduction Well designs for subsea field developments in water depths of 2000+ meters have unique requirements. Nearly 70% of Brazil's oil &gas reserves lie beneath deepwater (300- 1000m) and ultra-deepwater (>1000m). The successful exploitation of these reserves depends on the processes and technologies by which they can be safely, yet economically extracted in an environmentally sound manner. The economics of reducing well count while accessing the same targeted reserves and eliminating the high cost of re-entry are what make the utilization of intelligent well systems attractive. The integration of IWS into an environment requiring well lifetime sand control and zonal isolation has required an evolution of technology.