Method for preventing steam channelling into a non-aquifer bottom water zone

A method for closing pores in a bottom water zone of a formation comprising:

• (a) heating the bottom water zone by steam flooding to a temperature greater than about 300.degree. F. which temperature is sufficient to activate a gellable mixture and cause it to form a solid gel;
• (b) ceasing steam injection into the formation upon reaching said temperature in the bottom water zone;
• (c) injecting into the formation a temperature activated gellable aqueous mixture which contains sufficient amounts of a polymer selected from a member of the group consisting of polyvinyl alcohol, polyacrylamide, sulfonated polyvinyl alcohol, and poly (acrylamide-co-acrylamido-2-methylpropane sulfonate) cross-linked in situ with a phenolic compound and an aldehyde producing compound in an amount sufficient to form a solid gel;
• (d) activating said mixture upon reaching a temperature of about 300.degree. F. so as to form a solid gel and close pores in said bottom water zone;
• and
• (e) removing any ungelled mixture from the formation.

A method for closing pores in a bottom water zone of a formation which has a temperature greater than about 300.degree. F. comprising:

• (a) conducting a steam flooding enhanced oil recovery process in a formation's bottom water zone until steam breakthrough occurs thereby heating said zone to a temperature greater than about 300.degree. F.;
• (b) ceasing injection of steam into the formation upon reaching said temperature in the bottom water zone;
• (c) injecting a temperature activated gellable mixture into the formation which mixture comprises water, polyvinyl alcohol, phenol and trioxane in an amount sufficient to form a phenolic resin in situ and cross-link with said alcohol at a temperature greater than about 300.degree. F.;
• (d) allowing said mixture to remain in the formation for a time sufficient to form a solid gel in said bottom water zone of said formation having a temperature greater than about 300.degree. F.;
• (e) injecting cold water into the formation in an amount sufficient to prevent any ungelled mixture from forming a solid gel;
• and
• (f) injecting thereafter steam into the formation which enters an upper zone of the formation where the temperature was not previously heated above about 300.degree. F. and removing hydrocarbonaceous fluids therefrom.