| Full text | |
| Author(s): |
Matheus, Gabriela Fernandes
;
Basso, Mateus
;
Souza, Joao Paulo da Ponte
;
Vidal, Alexandre Campane
Total Authors: 4
|
| Document type: | Journal article |
| Source: | TRANSPORT IN POROUS MEDIA; v. N/A, p. 30-pg., 2023-08-11. |
| Abstract | |
The porous systems of carbonate reservoirs show a great diversity of pore types and high heterogeneity that can reflect the interplay of several elements including physical, chemical, and biological depositional processes, intense diagenesis, fracturing, and hydrothermal alterations. All these factors combine in the Aptian Barra Velha Formation carbonates from Santos Basin, SE offshore Brazil, which comprises the most prolific hydrocarbon reservoirs from Brazil. The geological complexity of this formation has represented a major challenge for oil forecast, recovery and production. The absence of outcrops, proper analogs and the limited access to core samples of this deep formation adds to the challenges involved in the geological and petrophysical characterization of such reservoirs. In this context, X-ray computed tomography (CT) can become a key technique applied for non-destructive quantitative analyses and 3D visualization of different rock structures. The present article reports the results obtained from X-ray CT images applying digital rock analysis to characterize the complex pore networks and mineral phases of the Barra Velha Formation reservoir. Multi-resolution CT-scan petrophysics was combined with detailed petrography and petrology, aiming to understand the geological factors controlling porosity distribution. Mineral segmentation was split into three mineral phases: carbonate, undefined (microporosity and diagenetic material) and dense minerals. The high percentage of undefined phase was commonly associated with intense dolomitic cementation and related to low permeabilities. Shrubstone and Intraclastic rudstone lithologies showed the best reservoir properties, mainly when the dominant growth framework and interparticle porosity, was associated with dissolution, enhancing the pore connectivity. Pore network analysis revealed the tendency of larger pores to be associated with higher coordination numbers, presenting greater pore connectivity. This study aims to contribute to future work on Brazilian pre-salt carbonates' pore type and multi-scale characterization, providing new insights into the characteristics and factors related to the samples' connectivity. (AU) | |
| FAPESP's process: | 17/15736-3 - Engineering Research Centre in Reservoir and Production Management |
| Grantee: | Denis José Schiozer |
| Support Opportunities: | Research Grants - Research Centers in Engineering Program |