CHANGES IN THE PRODUCTIVITY OF A CIRCULAR FORMATION UNDER CONDITIONS OF ZONAL HETEROGENEITY

Abstract

The paper discusses the task of evaluating well productivity in a zone-heterogeneous formation, taking into account the effect of hydraulic fracturing of the formation. An analytical model of filtration is proposed, based on the representation of a productive formation in the form of a circular region divided into several zones with different filtration and reservoir properties. For each zone, individual permeability values   are taken into account for a constant formation thickness. An analytical expression was obtained for the well productivity index, which allows taking into account the influence of permeability heterogeneity, geometric parameters of the system and boundary conditions. The resulting relationship was analyzed, which showed that with certain ratios of parameters, an increase in well production rate is possible compared to a homogeneous formation.

Particular attention is paid to assessing the impact of fracture parameters and elastic properties of the formation-fluid system on filtration characteristics and productivity. It was found that matching the parameters of compressibility of the crack and elasticity of the porous medium leads to a maximum increase in the productivity coefficient. The obtained results can be used in modeling the development of multilayer fields, as well as in optimizing the parameters of hydraulic fracturing to increase oil recovery of low-permeability reservoirs.