PRODUCTION FACILITIES GROUPING BASED ON THE PARAMETERS OF THE CAPILLARY PRESSURE CURVES GENERALIZED MODEL ON THE EXAMPLE OF WESTERN SIBERIA OIL FIELDS

Abstract

The relevance. The grouping of facilities allows, already at the stage of the field exit from exploration, classifying new deposits as any of the known analogue one being in development. Using the experience of long-term developed analogous fields in the exploitation of new facilities is undoubtedly a relevant procedure. The purpose: identifi-cation of an analogous facility by employing a limited number of indicators integrally characterizing the facility in question. The objects: productive strata of the Jurassic and Lower Cretaceous age of a number of fields in Western Siberia. Methods: statistical data processing of core samples capillarimetric studies from a number of productive formations of individual fields, a mathematical model of capillary pressure curves creation. Results. When identifying analogous objects, it is proposed to use a generalized model of capillary pressure curves, which is the dependence of the dimensionless capillary pressure on the normalized (reduced) water saturation in a logarithmic coordinate system. For any field in the conditions of Western Siberia the capillary characteristics of the productive formation are studied on the laboratory core samples collection. The filtration-capacity properties of the samples: porosity, permeability, residual water saturation, are determined. Further, by the laboratory data statistical processing, it is possible to obtain a generalized mathematical model of capillary curves. The generalized model parameters a, b and c are the characteristics of a given productive formation, and every productive formation is uniquely characterized by its own parameters. These parameters are unchanged for a specific productive formation, but different for the layers of different oil fields. The parameter a determines the wettability degree of the surface of the pore channel, that is, the water-retaining capacity of the productive formation. The parameter b characterizes the micro-heterogeneity of the channels in their size, as well as the share of the channels in the liquid filtration process. In addition, the relative phase permeabilities for the wetting (water) and non-wetting (oil, gas) phases for different water saturations are determined as well by the b parameter. The parameter c characterizes the capillary pressure curve behavior in the area of minimum values of the pore channel sizes. Thus, the generalized model of capillary pressure unequivocally characterizes the given operational facility, and the parameters of the model can be used to recognize an analogous object under development. Obviously, the experience of an analogous object developing can be confidently used in developing considered field.

Keywords

• capillary pressure curve
• generalized model
• grouping of facilities
• capillarimetric studies
• filtration-capacity properties