Typical reservoirs of high-gravity oil come to depletion at this time and oil production slows. Currently, enhanced oil recovery technologies are being developed to extract scavenger oil from jointed carbonate reservoirs. Extraction of hydrocarbons from such reservoirs is connected with integrated investigation of rocks, including geomechanical research. This article describes assessment of horizontal stress values in borehole environment on the basis of geomechanical modeling. The values of stresses depend on systems of joints in carbonate reservoirs under varying stress tensor. The object of research is oil-filled jointed carbonate reservoirs. The scope of the research included the stress-strain analysis of carbonate reservoirs fractured by systems of joints extracted from the geotechnical logging of core. Using 3D finite-element model built in Midas GTS NX, numerical models of different areas in borehole environment are developed.