Kharazmi Journal of Earth Sciences

Kharazmi Journal of Earth Sciences

Determination of geomechanical parameters of Sarvak formation using seismic, and well-log data in one of the hydrocarbon fields at the southwest of Iran

Authors
Hessam Mansouri Siah Goli
Mohammad Ali Riahi
Institute of Geophysics
10.52547/gnf.6.2.425
Abstract
Nowadays geomechanics plays a major role in optimizing the production and development stages of hydrocarbon reservoirs. The high cost of drilling wells and maintaining a functional well entails companies to utilize geomechanical modeling to determine the most efficient drilling path and the safest mud windows in order to maintain the stability of the well and prevent critical fracturing and collapses to occur. Using seismic data and well logs, one could estimate geomechanical properties such as elastic moduli, pore pressure, and especially the stress field of the reservoir. Knowledge of the stress regime present in the region of interest helps to determine the most suitable azimuth and inclination for drilling wells and estimating the mud weight window in order to optimize the drilling operation.

In this article, in order to model the in-situ stresses and pore pressure, the regression of these values versus the acoustic impedances was obtained for the reservoir formation of an oilfield located south-west of Iran. The pre-stacked seismic data inverted for using well-log data to achieve the acoustic impedance values corresponding to the seismic horizon. The regression model for maximum and minimum horizontal stresses and the pore pressure obtained for a specific well. The regression models are then used to transform the inverted data to achieve a 3D model of the mentioned geomechanical parameters. The utilized methodology validated by comparing the modeled values for the geomechanical parameters and the corresponding values in the well. Then, based on the classification of Anderson fault theory, in one of the wells in the study area, the fault regime was determined as a Normal fault.
Keywords
Geomechanical parameters
Poisson’s ratio
Prestack inversion
Stress field
Normal fault
Young’s modulus
Subjects
9. Alsharhan AS, Nairn AEM (1997) Sedimentary basins and petroleum geology of the Middle East. Elsevier, Netherlands

10. Abdollahie Fard I, Braathen A, Mokhtari M, Alavi S A,2006, Interaction of the Zagros Fold–Trust Belt and the Arabian-type, deep-seated folds in the Abadan Plain and the Dezful Embayment, SW Iran, Petroleum Geoscience, 12, 347–362.
11. Alavi M, STRUCTURES OF THE ZAGROS FOLD-THRUST BELT IN IRAN, American Journal of Science, 2007, 307, 1064–1095.
12. Anderson, E.M., 1905,The dynamics of faulting: Trans. Edinburgh Geol. Soc., 8 (3), 387-402.
13. Bahroudi A, Talbot C J,2003, THE CONFIGURATION OF THE BASEMENT BENEATH THE ZAGROS BASIN, Journal of Petroleum Geology, 26, 257-282.
14. Berberian M, 1995, Master "blind" thrust faults hidden under the Zagros folds: active basement tectonics and surface morphotectonics,Najarian Associates, Inc., One Industrial Way West, Eatontown, NJ 07724, USA, 241, 193-224..
15. Den Boer et al, 2006, From pore pressure prediction to reservoir characterization: a combined Geomechanics-seismic inversion workflow using Trend-kriging Techniques in a deepwater basin. Schlumberger. Houston. USA.
16. Eaton, B.A, 1975, The Equation for Geopressure Prediction from Well Logs." SPE 50th Annual Technical Conference. Dallas. SPE 5544-MS, 1975. 1-11.
17. Fjaer, E., Holt, R. M., Horsrud, P., Raaen, A .M., and Risnes, R., 2008,Petroleum Related RockMechanics 2nd Edition. Amsterdam Boston Heidelberg London New York Oxford Paris San Diego San Francisco Singapore Sydney Tokyo: Elsevier.

18. Gray, D., Anderson, P., Logel, J., Delbecq, F., Schmidt, D., Schmid, R., 2012, Estimation of stress and Geomechanical properties using 3D seismic data: first break volume 30.
19. Hosseiny, A. R. Baniasad & E. Dehyadegari (2016) The genesis of H2S associated with heavy oils in Hendijan and Bahregansar oilfields, Sarvak reservoir, Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 38:8, 1140-1147, DOI: 10.1080/15567036.2013.831145
20. James GA, Wynd JG (1965) Stratigraphic nomenclature of Iranian oil consortium agreement area. AAPG Bull 49:2182–2245
21. Kidambi, T., & Kumar, G. S,2016, Mechanical Earth Modeling for a vertical well drilled in a naturally fractured tight carbonate gas reservoir in the Persian Gulf. Journal of Petroleum Science and Engineering, 141, 38–51.
22. Zhang. J., 2011, Pore pressure prediction from well logs: Methods, modifications, and new approaches, Vo.108, Issues 1–2, 50– 63.
23. Zoback, M. D., 2007, Reservoir Geomechanics: Cambridge University Press.
Kharazmi Journal of Earth Sciences
Volume 6, Issue 2 - Serial Number 12
December 2020
Pages 425-444