Abstract: A secondary oil recovery method and system utilizing a concentric tank arrangement receiving crude oil from an oil well in the inner tank thereof with the crude oil being heated by a solar furnace to facilitate separation of water, oil and gas with the water being disposed within the outer tank for insulation of the inner tank and for use in an injection well for water flooding with the gas being removed from the inner tank from a dome trap at the top thereof and separated oil being moved to a storage tank or other point of use from the inner tank. The solar furnace includes heat exchange tubes disposed in the inner and outer tanks and oriented in relation to a heat collector panel and provided with a heat exchange medium therein by which solar energy is used to heat the crude oil in the inner tank as well as the water at the bottom thereof and water in the outer tank.

Abstract: A method for heating recovered crude oil at the site of recovery thereof and injecting at least a portion of such heated crude oil back into the oil formation in order to reduce the viscosity of oil remaining in the oil formation, the invention facilitates recovery of the remaining oil and renders the oil more easily handled through pumping operations. Apparatus according to the invention particularly provides for solar heating of a working fluid circulating through a closed heat exchange coil disposed within a crude oil storage tank located in proximity to one or more operating wells and normally used for temporary storage of oil pumped from the wells. Heat energy carried by the working fluid in the closed coil is transferred to the crude oil within the storage tank, the heated crude oil being then pumped back into the oil formation to heat the remaining oil in the formation, the viscosity of the remaining oil being reduced to allow a greater total recovery of the oil in the formation.