THE EFFECTIVENESS OF COMPOSITE SYSTEMS IN HETEROGENEOUS FORMATIONS

The article discusses one of the methods of increasing the efficiency of additional development of facilities and intensification of oil production. Under these conditions, work is underway to eliminate the predominant filtration of the injected water into the most permeable layers or zones. The basic principle of such work is to create an impenetrable or low-permeability barrier in the way of water filtration. This leads to a redistribution of filtration flows, the involvement of stagnant and poorly drained zones in the development, and contributes to an increase in oil recovery. The results of an experimental study of the effectiveness of the use of CS based on a 0,2% solution of polyacrylamide (PAA) and a 3% solution of diesel-alkaline waste (DRL) to increase oil recovery in layered heterogeneous formations are presented. The main attention is paid to the influence of the degree of waterlogging of the produced products and the pressure drop on the oil recovery coefficient (DEEP). The research was carried out on a laboratory model of a reservoir saturated with oil from the Bibieybat field at various levels of waterlogging. (50%, 70%, 100%) and pressure drops (0,003–0,022 MPa). It has been established that pumping CS into a highly permeable layer provides an increase in CIN due to the redistribution of filtration flows and the involvement of low-permeable zones in the development. The highest efficiency was achieved with the early application of CS (DEEP up to 0,805), whereas with complete watering, the indicator decreases to 0,655. It is shown that as the pressure drop increases, the efficiency of CS decreases, but even in extreme conditions, the technology retains a positive effect. Special attention is paid to statistical data processing using sequential Wald analysis, which made it possible to minimize the number of experiments while maintaining the reliability of the results. The optimal average value of DEEP (0,69) was determined for conditions of 70% water availability with an accuracy of 3,18%.