Geologically plausible computer-aided history matching on the example of one the oil fields

The existing methods for history matching (HM) in hydrodynamic modeling do not meet requirements for geologically plausible model. That significantly affects the quality and predictive ability of this models and hence the success of investment decisions. In this paper, the method of automatic HM is pre-sented. The method provides geological parameters control with preserving of identified petrophysical and geological uncertainty that significantly affect reservoir development process. Firstly, based on measured data and data from fields-analogues, realistic limits for each parameter and relationship in model were identified. Further, in order to provide the geologically plausible simulation model within a given geological concept, variation of one parameter or relationship during HM leads to variation of others parameters related to it within previously identified uncertainty range. For example, changes in parameters for porosity calculations leads to changes in parameters for permeability calculations, other model characteristics which related to permeability and so on. Iterative algorithm «evolution strategy» is used for automatic HM. During HM objective function based on mismatch of calculated and historical data for 50 well of sector model of one of the oil fields is mini-mized. As a result, number adapted models were obtained that demonstrate a good quality of HM. Based on these adapted simulation models forecasting of wells’ working parameters is made with taking into account the uncertainty of the initial data and geological characteristics. The distinctive feature of proposed method is the rejection of single deterministic relationships between petrophysical and geological parameters in favor of variations of these parameters within identified uncertainty range. This method allows speeding up HM and providing control of geological realism of simulation models. As a result, confidence in forecasting based on a set of adapted and geologically plausible models is increased.