4D Seismic Applied to Pre-Salt Carbonate Reservoirs: Challenges and Results from Tupi Pilot, Santos Basin

Abstract

Summary PETROBRAS concluded in 2020 the pioneering seismic project for monitoring Pre-Salt reservoirs, known as the Tupi Nodes Pilot project, using the time-lapse technique. The project involved 4D feasibility studies, two ocean-bottom-nodes (OBN) surveys and 4D seismic interpretation. Particularly for the Tupi field, but with the promise of serving as a field test for the entire Pre-Salt section, these 4D OBN surveys and studies will hopefully assist to identify oil-bypassed targets for infill wells, optimize the use of intelligent completion valves to improve the reservoir overall sweep and calibrate the water-alternating-gas (WAG) injection cycles to increase oil recovery. Given the technological character of this pilot, it is a huge achievement that time-lapse images reveal the capability of 4D seismic to correctly distinguish discrete fluid variations and its paths through the stiff carbonate reservoirs of Tupi field. The technical-entrepreneurial success of Tupi Nodes Pilot has become a reference for the entire oil industry and already underpins new 4D projects for the Brazilian Pre-Salt. This success reflects the interdisciplinary engagement of geophysicists, geologists and engineers from PETROBRAS Exploration and Reservoir Development areas.