An Application of Extended Well Tests for Formation Characterization and Productivity Evaluation in Carbonate Reservoirs

In the development of deep water carbonate oil field, the extended well test (EWT) is a common method for economically characterizing formation, providing critical information such as formation connectivity, reservoir boundaries and drainage volume. It can also be applied for assessing well capacity for production, which would reduce risks for production in long term and help operators make decisions for oilfield development. In this paper, by interpreting EWT data from a deep-water carbonate reservoir in Brazil, both the formation connectivity and heterogeneity in horizontal and vertical direction are estimated. Also, through long-term production data, the productivity of the carbonate reservoir can be evaluated, which provides a reference for planning the production of new wells. The efficient application and interpretation of extended test data is of great significance to the formation characterization and productivity evaluation for carbonate reservoirs.