The most industrially developed methods of enhanced oil recovery of the production of high-viscosity oils and natural bitumen are thermal methods of influencing the reservoir: steam cyclic stimulation of production wells, steam assisted gravity drainage, and areal steam injection. The thermal methods also include the thermomine method, which involves the construction of underground mine working with galleries of producing wells and a thermally enhanced oil recovery. An example of using the thermomine method – the Yarega area of the Yarega field. The technology of the thermomine method are continuously being improved during the development of Yarega area. The most common the underground-surface method: the steam is injected from the surface through vertical steam injection wells, and oil is extracted in the underground mine through gently sloping production wells. The practice of areal steam injection and the results of geophysical studies of steam injection wells have shown that when using the underground-surface method of production the Yarega area, the steam mainly enters the upper part of the reservoir, which implies uneven production of reserves in thickness. There is a need to increase the pressure of steam injection in order to involve reserves of extra-viscous oil in the process of the heat carrier treatment. However, an increase in the injection pressure of the steam is problematic in some cases due to the presence of heterogeneities in the formation (disjunctive seismic faults every 20-25 m, as well as numerous microfractures with fissure opening). The paper presents the results of an experimental study of the use of sedimentation compounds during steam injection under different thermobaric conditions. The scientific novelty is to evaluate the effectiveness of the use of sedimentation compounds when injecting steam into zonally heterogeneous sand packed tubes. Solutions of iron sulfate, sodium carbonate, and calcium chloride were selected as sedimentation compounds. The average permeability of the heterogeneous sand packed tube was reduced by 55 % when steam was injected with a temperature of more than 170 °C as a result of performing three treatments with sedimentation compounds. The effective pore volume during steam injection has been increased by 70.6 %, which, during well tests affects an increase in the surface efficiency of steam treatment, and as a result, an increase in oil recovery.