Geostatistical Modeling of Geomechanical Elastic Moduli Using Well and Seismic Data

Geostatistical Modeling of Geomechanical Elastic Moduli Using Well and Seismic Data

The rock elastic properties often have impact on optimization of drilling trajectory, selection of weight on bit during drilling operation, selection of appropriate zone/depth interval for hydraulic fracturing operations, etc. The main concern of this study is 3D modeling of the geomechanical elastic properties, which is one of the five major components of any geomechanical reservoir model. However, due to the limited/sparse available data compared to the volume of a reservoir, the estimation of spatial distribution of the geomechanical properties in the 3D framework of the reservoir is challenging. In this context, the geostatistical simulation techniques can be used to model the geomechanical parameters in three-dimensional space. The data for this study comes from a hydrocarbon field located in south west of Iran, which includes forty wells and 3D seismic data. First, the dynamic elastic moduli are computed from well logging data. Then, using the laboratory rock mechanical data and empirical relationships, dynamic elastic moduli are transformed to the static elastic moduli. Next, one dimensional modeling of the elastic moduli of rock (including Young’s modulus, Shear modulus, Balk modulus, and Poison’s ratio) are performed at the wells using the petrophysical and laboratory data. Later, three-dimensional modeling of elastic moduli is performed using the geostatistical estimation and simulation techniques. In order to see the validity and precision of the modeled elastic parameters of rock, we have investigated the effect of the simultaneous employing of the seismic data and well logs using various cosimulation methods. The results indicate that seismic-constrained geostatistical modeling, improves the correlation coefficient at test well from 60% to 87%. This implies that in our case study the use of secondary information (seismic data) in geostatistically simulation of reservoir geomechanical parameters has considerable impact