High viscosity of heavy oils at reservoir conditions is one of the main causes of the low production rates of producing wells, and sometimes even their complete absence when trying to develop a field on a natural mode. The rheological properties of heavy oil deposits in a wide temperature range were studied in this work. Special attention was paid to the study of viscous and elastic components of oil viscosity as a function of temperature to justify the optimal conditions for the development of heavy oil fields. Heavy oil samples collected from Pechersky oil field (Russia) were used in this research. Dynamic viscosity tests were carried out on the heavy oil of this field. It was noticed that high values of viscous and elastic components of oil viscosity were observed over the entire temperature range. It has also been remarked that the values of oil viscosity components are inversely proportional to the temperature increase.

Oil and gas production using formation thermal stimulation or treatment represents one of the main enhanced oil recovery methods. In this study the thermal properties of rocks and their relationship to the nature of rock saturation were investigated.The method, experimental setup, and results of studying the thermal characteristics of fine - and medium-grained highly porous sandstones at their different saturation are presented. The highest values of thermal diffusivity, thermal conductivity and heat capacity correspond to water-saturated samples, smaller values correspond to oil-saturated ones and the lowest values corresponds to dry (extracted) samples. The obtained data can be used in the selection of the technology of thermal formation stimulation on the reservoir and control over the process of oil field development.