Tupi Nodes pilot: A successful 4D seismic case for Brazilian presalt reservoirs

Abstract

The oil and gas industry has established 4D seismic as a key tool to maximize oil recovery and operational safety in siliciclastic and low- to medium-stiffness carbonate reservoirs. However, for the stiffer carbonate reservoirs of the Brazilian presalt, the value of 4D seismic is still under debate. Tupi Field has been the stage of a pioneering 4D seismic project to field test the time-lapse technique's ability in monitoring production and water-alternating-gas (WAG) injection in the Brazilian presalt. Ocean-bottom node (OBN) technology was applied for the first time in the ultra-deep waters of Santos Basin, leading to the Tupi Nodes pilot project. We started with feasibility studies to forecast the presalt carbonate time-lapse responses. The minerals that constitute these carbonate rocks have an incompressibility modulus that is generally twice as large as those of siliciclastic rocks. This translates into discrete 4D signals that require enhanced seismic acquisition and processing techniques to be correctly detected and mapped. Consequently, two OBN seismic acquisitions were carried out. Time-lapse processing included the application of top-of-the-line processing tools, such as interbed multiple attenuation. The resulting 4D amplitude images demonstrate good signal-to-noise ratio, supporting both static and dynamic interpretations that are compatible with injection and production histories. To unlock the potential of 4D quantitative interpretation and the future employment of 4D-assisted history-matching workflows, we conducted a 4D seismic inversion test. Acoustic impedance variations of about 1.5% are reliably distinguishable beyond the immediate vicinity of the wells. These 4D OBN seismic surveys and interpretations will assist in identifying oil-bypassed targets for infill wells and calibrating WAG cycles, increasing oil recovery. We anticipate that studies of the entire Brazilian presalt section will greatly benefit from the results and conclusions already reached for Tupi Field.

BrainPuzzle: a new data-driven method for ultrasound brain imaging

“…3 Both RTM and FWI methods are specifically designed to manage the high-velocity contrast challenges, particularly in hydrocarbon detection within salt basins. [4][5][6][7] This significant velocity contrast in geological contexts mirrors the challenges encountered in brain imaging beneath the skull bones. This scenario in brain imaging is analogous, with the skull bones, much like salt bodies, presenting a similar high-velocity barrier to the underlying tissues.…”

Assessing Time-Lapse Full-Waveform Inversion Strategies in a Brazilian Pre-Salt Setting

“…This shift towards OBN surveys has been driven by the inherent difficulties associated with streamer surveys in managing NR, azimuth illumination, fold and longer offsets concerns Cypriano et al (2019). A case in point is the Tupi Nodes pilot project, a study conducted by Cruz et al (2021), which underscores the advantages of OBN technology in the context of deep-water Brazilian pre-salt reservoirs. The Tupi Nodes pilot project demonstrated a highly favorable time-lapse response by leveraging full-waveform inversion (FWI) (Virieux and Operto, 2009) as an integral component of the timelapse seismic processing toolkit.…”