A COMPUTER-IMPLEMENTED METHOD AND A SYSTEM FOR DETERMINING EFFECTIVE ELASTIC PROPERTIES OF A SAMPLE OF A POROUS MEDIUM

摘要

A computer-implemented method for determining effective elastic properties of a sample of a porous medium includes selection of at least one sub-volume in the volume of a sample. The sample is scanned and the obtained three dimensional digital image of the sample is used for creating three dimensional digital representations of the selected sub-volumes. The initial representative volume elements (RVEs) are selected from the created digital representation of any sub- volume. This RVE is used for creation of a numerical model and further definition of effective elastic properties. Then the second bigger RVE is selected from the same place of the sub- volume. The second RVE is also used for creation of a numerical model and further definition of effective elastic properties. After that the values of effective elastic properties are compared for two cases and the relative differences between them is calculated. If the values of obtained relative differences are less than an initially defined permissible relative difference, the volume of the initially selected RVE is taken as the size for all RVE for considered sub- volume. If the value of the obtained relative differences are bigger than the defined permissible relative difference, the bigger volume of RVE must be re-selected from the digital representation of sub-volume of the sample. The process may be repeated n times until (n-1) and (n) RVEs are meeting the requirements about values of the relative difference. The finally defined size of (n-1) RVE is used for selection of all other RVEs from the considered digital model of sub-volume of rock core. These RVEs are used for creation of finite-element numerical models and further definition of effective elastic properties.