Modern Geosteering Technologies as the Enhanced Efficiency Method of Reserve Development in Marginal Zones—Bottom Waterdrive Reservoir of Vikulov Suite at Kamenny License Area, Krasnoleninskoye: Field Case Study

Abstract

Hydrocarbon deposits of the Vikulov suite are currently the primary development targets for OAO "Rosneft-Nyaganneftegaz." More than 90% of the base production from the Em-Yogovskiy and Kamenny license areas consists of these horizon reserves. This became possible by drilling out conventional traps, dome, and incised river valley areas with lower oil water contact (OWC) than in other areas. In spite of this, less than a half of the oil in place reserves of this horizon appear to be involved in production, though much of these reserves are marginal zones. The primary problems developing such reserves are relatively small net oil thickness (net pay thickness), the presence of mobile water, high OWC, and the absence of a reliable seal between oil-saturated (VK1) and water saturated horizons (VK2 and VK3). All of these factors contribute to the reduced efficiency of the primary method for production stimulation in this horizon—hydrofracturing. One solution to help address the current situation is drilling of horizontal wells in oil-saturated upper layers. When developing these reserves, it is particularly important to create an accurate and detailed geological model of the deposit to help identify high-risk zones with potential minor faults. When drilling in a formation of true thickness less than 2 m, it is necessary to know the exact location of the borehole in relation to the structure to help prevent, if possible, drilling out of the reservoir.