Estimating the Elastic Modulus of Reservoir Rock by Petrophysical Information Using the Geostatistical Method

Abstract

Mechanical properties of reservoir rocks play an important role in drilling and production of a hydrocarbon reservoir. In addition, part of elastic modulus in determination of capability of drilling, wellbore stability analysis, sand production, as well as in determination of in situ stress field, is effective. To estimate these parameters, there are several methods, one of which is application of reservoir's petrophysical data. In this article, through using neutron and density logs and photoelectrical data, lithology of reservoir was first determined and at the next stage through applying petrophysical data, lithology, and also by means of empirical relations between travel time of shear wave and compression wave, travel time of shear wave was obtained. Then elastic modulus was calculated according to the relations existing. By using geostatistical method, such as kriging, rock's geomechanical property was evaluated vertical and continuously and with the least existing error. Furthermore, the amount of sensitivity to these data in relation to the selective variogram model and lags between points and the number of adjacency points will be examined and shown.