Optimization of parameters of inorganic profile control agent on the basis of sodium silicate for effective oil displacement from high salinity reservoir

The relevance. Oil field Tuha is a medium and low permeability reservoir, with high salinity water. Currently, the water cut of the main productive layer in the «Y» section of the Tuha oil field is more than 93 %. Existing polymers and salt-resistant polymers cannot be well dissolved and distributed in layer water, and also have poor retention in the reservoir and profile control ability, hence, it is difficult to achieve a good technical and economic effect. So, it is important to investigate the method of profile management for effective oil displacement from reservoirs with high mineralization. The main aim of the research is to study oil displacement efficiency and optimization of parameters of inorganic profile agent based on sodium silicate for enhanced oil recovery. Methods. Viscosity of the studied samples was determined on a Brookfield DV-II viscometer; the experiments investigating the effect of the slug size of main agent, the number of cycles of alternative waterflooding, the injection speed of main agent and the injection of surfactant on the oil displacement efficiency were carried out on filtration unit. Results. In order to satisfy the demand of enhanced oil recovery at this oil field, the experimental studies were carried out to optimize parameters and increase the efficiency of oil displacement of the inorganic silicate profile control agent based on the geological characteristics of the reservoir and fluid properties of the «Y» sections. The results show that when the size of the slug of the main agent is from 0,06 to 0,08 V_inj/V_pore, and the cycle of alternative flooding is 5-6, the degree of using the layers with medium and low permeability is higher, the water cut decreases and oil recovery increases significantly. Compared to single silicate flooding, the combination of silicate and surfactants can achieve the goal of expanding the scope of coverage and improving the efficiency of oil displacement, and increases the oil recovery factor.