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

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