PROCESS FOR SEQUENTIALLY APPLYING SAGD TO ADJACENT SECTIONS OF A PETROLEUM RESERVOIR

摘要

Steam assisted gravity drainage ("SAGD") is practised in a first section of a reservoir containing heavy oil. When production becomes uneconomic, steam injection into the first section is terminated. Non-condensible gas is then injected into the section to pressurize it and production of residual oil and steam condensate is continued. Concurrently with pressurization, SAGD is practised in an adjacent reservoir section. As a result, some of the residual oil in the first section is recovered and steam loss from the second section to the first section is minimized.