A method of enhancing conductivity within a hydrocarbon-bearing reservoir by building proppant pillars in a spatial arrangement in fractures created or enlarged in the reservoir. Two fluids of differing stability are simultaneously pumped into the reservoir. The fluids may contain identical proppant mixtures which include a first proppant which has an apparent specific gravity less than the apparent specific gravity of a second proppant. The fluids may contain identical proppants mixtures where the average particle size of a first proppant is greater than the average particle size of a second proppant. Vertically extending pillars are created within the formation when the fluids are destabilized and the first proppant is then released from the destabilized fluids. The area between the pillars may be held open by the presence of the second proppant in the remaining fluid. Fluid produced from the hydrocarbon-bearing reservoir is then flowed at least partially through channels between the vertically extending pillars.