A MULTI-DISCIPLINARY RESERVOIR CHARACTERIZATION OF SOĞUCAK FORMATION, NORTHWEST THRACE BASIN, TÜRKİYE; A DETAILED APPROACH TO MINIMIZE UNCERTAINTY IN CARBONATES

Date

2023-8-22

Author

Karaca, Ergin

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

234
views

350
downloads

Cite This

Characterizing a mature complex reefal carbonate reservoir with 3D seismic data, where wells have previously produced and acid stimulation has been applied, presents unique challenges compared to undeveloped fields. This study focuses on the complex reefal limestones of the Soğucak formation in the Deveçatağı oil field, which was discovered in 1974 in the northwest Thrace basin of Türkiye. The 3D reflection seismic data used for this research was acquired in 2007, following 33 years of production from the discovery. This research integrates a comprehensive dataset across varying scales to better understand the depositional environment, diagenetic history, petrophysical evolution, production mechanisms, and the evolution of the seismic signals after years of production, using a multidisciplinary approach. Petrographic analysis of core plug data revealed the deposition in open shelf, shelf margin, and restricted shelf/lagoon environments, highlighting the heterogeneity of the Soğucak limestones. Diagenetic mechanisms such as dissolution, cementation, and neomorphism were identified in the Deveçatağı oil field, suggesting a possible exposure to meteoric waters over a specific time period. A Python program developed for this research connected high-resolution thin section images with core plug measurements, finding strong correlations with porosity values. Petrophysical and rock physics analysis, along with 2D synthetic studies, identified the acoustic impedance as a key parameter for assessing oil-saturated intervals. Results from the pre-stack stochastic inversion highlighted the significance of frequency content for resolution, particularly when the inversion outputs were integrated into a high-resolution geomodel. Analyzing drilling-induced fractures provided insights into stress orientations and the potential presence of open fractures within the Soğucak formation. Furthermore, establishing a direct correlation between acoustic impedance and production, along with the forward modeling of acoustic impedance maps spanning from 1974 to 2022, provided valuable insights into the physical evolution within the reservoir over the years.

Subject Keywords

Trace basin, Carbonate reservoirs, Stochastic inversion, Deterministic inversion, Geostatistical modeling, Naturally fractured reservoirs, Reservoir Characterization

URI

https://hdl.handle.net/11511/105323

Collections

Graduate School of Natural and Applied Sciences, Thesis