1887

Abstract

Summary

The Barra Velha Formation hosts giant oil and gas fields producing from the presalt of Santos Basin, in southeastern Brazilian coast. We show evidence from cores that the Barra Velha Formation was affected by intense fracturing, faulting and diagenetic processes with hydrothermal imprint. U-Pb geochronology was used to anchor cement filled fractures in time. Fault planes mineralized by dolomite could be dated at ca. 95 Ma. Fluid inclusion and geochemistry suggests participation of mantle volatiles and fluid mixing. Widespread dissolution of structural framework formed vuggy fractures, that can be partially filled by barite, quartz and solid bitumen. We show a timeline of diagenetic events that affected fracture framework and infer that fracture porosity is more likely to be preserved where deep faults enabled fluids from greater depth to ascend into the reservoir, where they created large vuggy cavities by dissolution of host rock and fractures.

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/content/papers/10.3997/2214-4609.2024637047
2024-10-06
2026-03-09

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References

  1. Aubert, I., Léonide, P., Lamarche, J., & Salardon, R. [2020]. Diagenetic evolution of fault zones in Urgonian microporous carbonates, impact on reservoir properties (Provence-southeast France). Solid Earth, 11, 1163–1186.
     [Google Scholar]
  2. Corrêa, R. S. M., Ukar, E., Laubach, S. E., Aubert, I., Lamarche, J., Wang, Q., … & Larson, T. E. [2022]. Episodic reactivation of carbonate fault zones with implications for permeability–An example from Provence, Southeast France. Marine and Petroleum Geology, 145, 105905.
     [Google Scholar]
  3. Corrêa, R. S. M., Carvalho, B., Ukar, E., Laubach, S., Pestilho, A., Fall, A., Larson, T., Stockli, D., Stockli, L., Lüders, V., Niedermann, S., Banks, D., [2024]. Brittle deformation and hydrothermal alteration in the Barra Velha Formation, Santos Basin, offshore Brazil. AAPG Bulletin. (In review)
     [Google Scholar]
  4. Fernández-Ibáñez, F., Jones, G. D., Mimoun, J. G., Bowen, M. G., Simo, J. A., Marcon, V., & Esch, W. L. [2022]. Excess permeability in the Brazil pre-Salt: Nonmatrix types, concepts, diagnostic indicators, and reservoir implications. AAPG Bulletin, 106(4), 701–738.
     [Google Scholar]
  5. Laubach, S. E., Eichhubl, P., Hilgers, C., & Lander, R. H. [2010]. Structural diagenesis. Journal of Structural Geology, 32(12), 1866–1872.
     [Google Scholar]
  6. Lima, B. E. M., Tedeschi, L. R., Pestilho, A. L. S., Santos, R. V., Vazquez, J. C., Guzzo, J. V. P., & De Ros, L. F. [2020]. Deep-burial hydrothermal alteration of the Pre-Salt carbonate reservoirs from northern Campos Basin, offshore Brazil: evidence from petrography, fluid inclusions, Sr, C and O isotopes. Marine and Petroleum Geology, 113, 104143.
     [Google Scholar]
  7. Roberts, N. M., Drost, K., Horstwood, M. S., Condon, D. J., Chew, D., Drake, H., … & Lee, J. K. [2020]. Laser ablation inductively coupled plasma mass spectrometry (LA-IC P-MS) U–Pb carbonate geochronology: strategies, progress, and limitations. Geochronology, 2(1), 33–61.
     [Google Scholar]
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Natural Fractures and Hydrothermal Alteration in the Brazilian Pre-salt - An Example from Santos Basin
Conference Proceedings 2024, 1 (2024); https://doi.org/10.3997/2214-4609.2024637047
/content/papers/10.3997/2214-4609.2024637047
/content/papers/10.3997/2214-4609.2024637047
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