SELECTION OF FLOW DIVERSION TECHNOLOGY FOR A CARBONATE RESERVOIR OBJECT

 The paper presents the results of selecting flow-diverting technologies (FDT) and their testing at a facility with a carbonate reservoir type, which is developed using a network of horizontal wells and has complicating factors such as high reservoir temperature (90 °C) and high salinity of formation water (over 150 g/L). These conditions significantly limit the application of conventional enhanced oil recovery (EOR) methods, as the use of common technologies such as precipitation-forming and polymer-dispersion compositions in extended-reach and horizontal wells carries the risk of irreversible blockage of the horizontal wellbore sections due to the settling of dispersed particles under gravity. Additionally, some reagents lose their technological properties and stability under high salinity and temperature conditions.Thus, the objective of this work was the selection and adaptation of FDT capable of functioning under extreme conditions to block high-permeability channels and optimize oil displacement. At the first stage, a theoretical analysis of existing technologies was conducted, and their selection was carried out considering the geological and physical characteristics of the test site. Subsequently, laboratory studies of optimal technologies for the given conditions were performed, along with field implementation support for the selected FDT.The conducted research revealed that the efficiency of flow-diverting technologies largely depends on their stability under high-temperature and high-salinity conditions. Various polymer and gel-forming systems were analyzed, among which the most degradation-resistant at 90 °C and in a high-salinity environment were identified. Laboratory experiments also assessed the compatibility of the selected compositions with reservoir fluids and rock, minimizing the risks of precipitate formation and permeability reduction in low-permeability intervals. As a result, compositions suitable for enhancing oil recovery in carbonate reservoirs with challenging geological and physical conditions were identified.The experience of applying FDT highlights the importance of laboratory testing and technology adaptation to field-specific conditions. The obtained results demonstrate that the use of adapted FDT can increase the oil recovery factor even in complex geological and technical conditions typical of carbonate reservoirs with high temperature and formation water salinity.