Unique Romashkino Oil Field in Tatarstan Republic is an Inexhaustible Source to Add Oil Reserves

Khisamov, R.S., V.G. Bazarevskaya, OAO Tatneft, Tatarstan, Russia

Discovery and development of Romashkino oilfield in 1943 made a significant contribu­tion to the global petroleum science. For the first time advanced exploration and oil reserve development techniques were successfully implemented on a large scale in the oil field. In the oil field stratigraphic section 22 horizons in Devonian and Carboniferous strata were identified to be oil-bearing, 18 of which proved commercial oil presence. Over 400 deposits have been discovered to date. The petroleum geologists suppose that one of the unique ele­ments of Romashkino field is the “replenishment” of oil reserves. The experience shows that as the geological study information expands and accumulates the quantity of evaluated and estimated reserves has been continually increasing in spite of oil production growth. Some experts explain this phenomenon by the errors made in the reserve estimates while the oth­ers consider this as the inflow or replenishment due to the hydrocarbon flow along the hid­den fractures as well as faults from the depths of crystalline basement. In order to study the current processes that take place in the subsurface of Romashkino field we perform researches and pilot field operations; a great deal of focus is made to the crystalline base­ment study; unconsolidated zones identification in the crystalline basement. We carry out abyssal seismic surveys and parametric drilling. The long-term study of the oil field per­formance history made it possible to identify the oil wells with abnormal production rates. In order to define oil migration paths we provided geochemical analyses of oil and etc.