Integrated workflow characterizes Campos basin fractured reservoirs using pressure-transient tests

摘要

In 2005, while drilling an exploration well about 120 km offshore in the Campos basin, Fig. 1, Petrobras discovered an oil-bearing carbonate reservoir above a salt section and beneath the clastic turbidites that provide most of the production in the area. A sequence of three pressure-transient well tests (DSTs) over three adjacent layers were performed in the first appraisal well, followed up two years later by a four-month extended well test (EWT) to help understand reservoir behavior and geology. Test results were sufficiently favorable to move forward, and a series of development wells were drilled. However, conventional analysis raised some concerns about the quantitative use of well-test data for reservoir modeling and characterization.