Method of improving steam-assisted oil recovery

Claim 1

A method of improving the recovery of oil from a hydrocarbon-bearing formation penetrated by a well and having a perforated liner in said well adjacent said formation comprising the sequential steps of providing a flow path from the surface to a location adjacent the lower portIon of a perforated well liner, providing a second flow path from said lower portion of said well liner to the surface, injecting steam down said first flow path into said well adjacent the lower portion of said liner, circulating said steam up said second flow path in said well adjacent said liner and venting substantially all of said steam to atmosphere to elevate the temperature of said liner to approximately the temperature of the injected steam prior to injecting steam out through said liner into said formation, closing in said second flow path, then injecting steam through said first flow path into said well through said perforations and into said formation and recovering oil from said formation.