Optimizing Production of Santos Basin Pre-Salt Fields through Sound Reservoir Management Practices

Abstract

Abstract Since the beginning of the Santos basin pre-salt commercial production, in December 2010, more than 1 billion barrels of high quality oil have been extracted from these ultra-deep water carbonate reservoirs. To enable and accelerate production, Petrobras and its partners applied advanced and innovative technologies in various areas of engineering. This paper focuses on the reservoir strategies conceived during the design phase of the Lula and Sapinhoá development projects and their application in these fields. The authors highlight practices and processes whose extensive use, in this type of scenario, were not standard. Among these, the dynamic characterization of the reservoirs by the use of long-term tests coupled with remote monitoring of pressure; water and gas production control by alternating injected fluids; intensive use of intelligent completion; convertible wells to accelerate production growth (ramp-up); CO2 injection from the start of production; rock-fluid interaction tests; optimization of well stimulation and many others. Knowledge acquired during the first seven years of commercial production and the actions implemented to manage the reservoirs reflect on the production plateau extension and the final length of their expected productive life. The collection and analysis of static and dynamic data proved to be valuable to reduce uncertainties and support further development decisions. Integrated effort contributed to risk mitigation, production maintenance and increased forecasted final recovery. The results obtained emphasize the importance of an effective reservoir management approach to maximize production and recovery. Concepts adopted are clarified through practical examples showing the advantages and gains from their implementation. The final message is that safe and viable operation of ultra-deep offshore fields benefits from additional investments in acquiring specific reservoir data. Their integrated analysis using advanced and up-to-date techniques is considered essential to maintain and improve asset values.