The article deals with the specifics of water and gas inflow isolation processes in horizontal wells. The main causes and sources of non-target fluid inflow into horizontal boreholes and the main technologies of repair and insulation works are described. Features of the choice of technologies to restrict the flow of water and gas in horizontal wells are considered. The characteristic features of different methods of isolating compounds injection - without horizontal hole zone isolation, with the use of in-casing packers, with the use of "liquid packer" or with the installation of a "chemical plugging packer" are singled out. The success rate of water shut-off and gas shut-off technologies worldwide has been analyzed and the most effective technologies of shut-off compositions injection have been determined depending on the type of fluid to be shut-off, type of reservoir and water or gas inflow site (toe, middle or bottom of the horizontal well). Effective technologies are also divided according to the completion method: open hole, liner without or with packers, liner with flow control devices, or a cemented liner. It is also noted that in some cases the problem cannot be solved by use of chemicals and technical means or targeted search for new efficient solutions is necessary. An analysis of isolating compounds potentially highly effective in shutting off both water and gas inflows has been carried out. A polymer composition, an aluminosilicate reagent and an organosilicon compound were chosen for laboratory tests. The critical pressure gradient, which the isolating compound can withstand without being carried away from the bulk reservoir model, was taken as the main parameter evaluated to determine the effectiveness of the isolation. Another estimated parameter is residual resistance factor, which characterizes the frequency of permeability decrease of model after injection of mixture. High efficiency of polymer systems and silicone-organic compositions for water and gas isolation, as well as applicability of aluminosilicate compounds for water shut-off works were determined in the laboratory. A ranking of types of isolating compounds in terms of applicability for water or gas shut-off has been carried out. The risks and required volume of isolating agents for the treatment of extended horizontal borehole intervals were assessed. The technology of directional injection of polymer system into the target interval using two-packer arrangement was justified to isolate water inflow in conditions of high risk of gas breakthrough, and field trials were conducted - a decrease in water cut of the production was achieved.
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