TECHNIQUE FOR INSULATING A WELLBORE WITH SILICATE FOAM

摘要

Disclosed herein is a method for thermally insulating a well for use in thermal processes for oil recovery. The well is insulated by boiling a silicate solution in contact with the well tubing to form a coating of alkali metal silicate foam on the tubing. Steam injection is continued without substantial interruption after excess silicate solution is no longer discharged at the surface. Preferably, steam injection is continued until water vapor from the silicate solution is no longer discharged at the surface. Generally, the steam which is injected during this continued period will be injected into an oil-bearing formation to thermally stimulate oil production.