JUSTIFICATION OF THE INTRODUCTION OF CYCLIC WATERFLOODING TECHNOLOGY AT A GEOLOGICALLY HETEROGENEOUS FORMATION OF THE OIL FIELD IN THE PERM KRAI

Abstract

The relevance of scientific work is caused by the existing problems of the development of carbonate productive deposits, characterized by a strong degree of geological heterogeneity. This feature directly affects the development, during which, in the conditions of these reservoirs, there is an uneven filtration of the injected agent and its movement through the most washed zones. These factors indicate an increased water content in the produced products and a low coverage of the reservoir by waterflooding, since the low-permeability areas of the reservoir remain outside the drainage zone. In order to solve this number of problems, according to world experience, various technologies are used, one of which is the technology of cyclic waterflooding, which has high efficiency and does not require significant capital and operating costs. The main aim of the research is to evaluate the effectiveness of the implementation of the technology of cyclic waterflooding in various options, including different duration of the half-cycle of the technology and combination with a number of geological and technical measures, in the conditions of a geological heterogeneous development formation. Object of the study is the Bashkir-Serpukhov formation of one of the deposits of the Perm Krai, which is characterized by a strong degree of heterogeneity according to the research results and is at the third stage of development. The analysis of the development of this object demonstrates a number of problems caused by the underestimation of its structure in full when designing the technological development scheme. Methods. Within the framework of this work, the Tempest MORE hydrodynamic simulator was used as a modeling tool. For modeling, an up-to-date geological and hydrodynamic model and built-in functionality of the simulator were used. Results. Based on the results of hydrodynamic modeling, a high efficiency of the proposed idea of introducing cyclic waterflooding technology at the target facility was obtained. The calculation results demonstrate the improvement in the main technological indicators of development in comparison with the base case, with the exception of the weighted average pressure in the hydrocarbon phase, since with a decrease in injection volumes, the energy state of the reservoir slightly deteriorates. Due to the periodic operation of the injection well stock, alternating pressure drops arise between highly (water-saturated) and low-permeable (oil-saturated) zones, due to which previously uncovered oil-saturated areas of the reservoir are involved in development. With the implementation of this technology, the forecast indicators reflect an increase in the level of oil production and decrease in the level of liquid production, which characterizes the success of the modeled technology. Based on all the implemented calculations, the authors have illustrated the most effective version of cyclic waterflooding in combination with geological and technical measures at a number of wells of the object under consideration.

Keywords

• oil reservoir
• geologically heterogeneous formation
• cyclic waterflooding
• reservoir coverage
• geological and hydrodynamic model