Well pattern infilling as a way to increase low-permeability reservoirs development efficiency

Abstract

The subject of the study is to study the influence of the well grid density for a low-permeable heterogeneous terrigenous formation in order to determine the optimal strategy for the reserves development. The paper analyzes various development systems implemented at the facility, as well as changes that occurred as a result of infill well drilling. In the process of information processing, actual data on the operation of wells at various sites were used, the values of recoverable reserves were estimated using statistical methods, calculations of various options were carried out using a hydrodynamic model in order to determine the implemented systems effectiveness, as well as to find ways to optimize them. It was found that for the conditions considered, the well grid infilling made it possible to increase the recoverable reserves amount by increasing the reservoir development coverage. Within the framework of the considered geological facility, the functional dependence of the oil recovery ratio and the the well grid density is obtained. The proxy modeling has shown that the necessary condition for maintaining the selections intensity is to maintain the flooding system rigidity. Taking into account the results obtained, the paper describes an approach based on which the potential for additional local grid infilling was estimated, taking into account the geological potential for involving reserves in development and the technological risk associated with zones of abnormally high reservoir pressure. Keywords: field development, low-permeability reservoirs, hard-to-recover reserves, infilling, drilling.