Capillary model – complex geological and petrophysical representation of the deposit when calculating geological reserves of hydrocarbons

Abstract

The basis for solving almost all geological problems are models, which are a reflection of the structure of deposits. This places high demands on the detail and accuracy of the models.One of the most important parameters in the calculation of reserves is the oil saturation factor, observed in most cases using Dakhnov-Archie models. Despite the widespread use of this technique, it has a number of significant limitations. An alternative way to assess oil saturation in this case is to use a capillary model obtained from the results of capillary measurements of the core.The capillary model is a continuous multidimensional function of the dependence of the water saturation coefficient on the free water level, porosity and permeability. A well-compiled capillary model is a reflection of the geological model of the reservoir – with information about the water saturation of the reservoirs by the altitude of the structure, the levels of fluid contacts, fluid densities, surface and reservoir properties.This paper discusses the capabilities of capillary models, which are widely used in three-dimensional modeling of the degree of saturation of the interwell space, the calculation of the volume of oil-saturated rocks, geological reserves of hydrocarbons, as well as dynamic characteristics in the construction of hydrodynamic models.

Keywords

• capillary model
• capillary measurements
• relative permeability
• hydrocarbon saturation index
• well logging