The vertical conformance of a steam drive process is improved and steam override reduced by penetrating the zone between one injector and one producer, with an infill well located between the injector and producer which is in fluid communication with no more than the bottom half of the formation. Steam is injected into the injection well in the first phase with production of fluids from the upper 1/3 or less of the formation via the production well. A separate flow path in communication with the bottom 1/3 or less of the formation is provided in the producing well, and is used during the first phase for push-pull treatment of the formation with solvent and steam or hot water. After production via the production well is terminated, petroleum is produced via the infill well until the fluid being produced from the infill well reaches 95 percent water cut, after which the infill well is converted from a producer to an injector and hot water is injected into the lower portion of the formation via the infill well and fluids are produced from the production well. After water breakthrough at the production well, steam is injected into the infill well and fluids are recovered from the lower 1/3 of the production well.