Patent ID: 9684084
Date: 2017-06-20
CPC Classifications: G01V,G06F

Claim:
1. A computer implemented method of forming with a computer system a static geological model of petrophysical properties representing the nature and structure, and the relative presence of microporosity and macroporosity, of the formations of a subsurface reservoir, the static geological model being organized into a number of cells arranged in an organized three-dimensional grid of cells according to the dimensions and volume of the reservoir, the static geological model being formed based on well logs obtained from wells in the subsurface reservoir, rock types of the subsurface rock formations, and well core description data comprising petrophysical measurements obtained from analysis of well core samples of rock formations adjacent cored wells of the wells in the subsurface reservoir in which core samples have been obtained, the method comprising the computer processing steps of: (a) forming a geostatistical model of the presence of lithofacies over the subsurface reservoir based on the well logs obtained from wells in the subsurface reservoir and the well core samples from the cored wells in the reservoir in which well core samples have been obtained; (b) forming a lithofacies model of postulated facies logs for the wells in the reservoir in which core samples have not been obtained, based on the petrophysical measurements from the well core samples for the cored wells in the reservoir; (c) forming a digital core description of the lithology of the cells of the subsurface reservoir as functions of depth in the well bores based on the formed initial geostatistical model of spatial distribution of the presence of lithofacies and the formed lithofacies model; (d) receiving identifications of the presence of macroporosity and microporosity in the subsurface lithofacies in the three dimensional grid of cells of the static geological model based on the testing of the well core samples obtained from the cored wells in the subsurface reservoir; (e) forming the static geological model of the petrophysical properties of the reservoir representing the nature and structure, and the relative presence of microporosity and macroporosity, of the formations of the reservoir by petrophysical uncertainty modeling based on: the well logs obtained from wells in the subsurface reservoir; the rock types of the subsurface rock formations; the well core description data obtained from analysis of the well core samples; and the identified presence of macroporosity and microporosity in the subsurface lithofacies; and (f) forming an output display of the static geological model of petrophysical properties representing the nature and structure, and the relative presence of microporosity and macroporosity, in the cells of the formations of the reservoir model for development of the reservoir.