Constructing a geomechanical conceptual model for Permian–Triassic reservoirs of the Persian Gulf

Abstract

In this paper, we present the construction of a geomechanical conceptual model for Permian–Triassic reservoirs of the Persian Gulf, achieved through a comprehensive comparison between geological facies, wireline data, and geomechanical parameters. Integrating geological and geomechanical data enabled the spatial distribution of key geomechanical parameters and the development of a conceptual model. This model offers valuable insights into the mechanical behavior of the various parts of the reservoir. Our database includes petrographical analysis of 1577 thin sections of 403 m of cores, routine core analysis, wireline logs, and geomechanical data in one well. Also, wireline logs from 6 other wells were used for correlation. Thin section studies showed 12 microfacies that have been deposited in a ramp depositional environment. Geomechanical data including Young modulus (E), Poisson ratio modulus (ϑ), shear modulus (G), bulk modulus (K), Schmidt hammer, and unconfined compressive stress (UCS), compared with geological and petrographical results. Electrofacies were constructed with the use of wireline log data. The incorporation of geomechanical data allowed for the construction of five geomechanical facies. The geomechanical features exhibit a progressive increase from one to five, indicating an inverse relationship with the reservoir quality of the electrofacies. Geomechanical units were defined by grouping similar geomechanical facies. Then, a relationship was established between geomechanical units and sea level changes. Subsequently, these units were correlated with sequence stratigraphic units and matched across the other six wells through the utilization of wireline logs. The spatial distribution of geomechanical units was determined by establishing their correlation with both geological facies and sequence stratigraphic units. Each geomechanical unit corresponds to the same depth interval of a systems tract belonging to a third-order sequence and a complete fourth-order sequence. This enabled us to detect and analyze the variations in the distribution patterns of geomechanical properties across the study area.