Treatment of an underground formation containing water-sensitive clays

Claim 1

A METHOD OF TREATING A WATER-SENSITIVE SANDCONTAINING FORMATION TO IMPROVE THE WATER PERMEABILITY OF THE SAND PORTION WHICH COMPRISES IN COMBINATION INJECTING INTO SAID FORMATION AND INTO CONTACT WITH SAID SAND PORTION THEREOF, AT AN ELEVATED TEMPERATURE AND A SUPERATMOSPHERIC PRESSURE, STEAM IN AN AMOUNT SUFFICIENT TO PROVIDE FROM ABOUT 0.1 TO ABOUT 10 PERCENT BY VOLUME THEREOF PER PORE VOLUME OF SAID SANDY PORTION OF THE FORMATION, THEREAFTER INJECTING INTO SAID FORMATION AND INTO CONTACT WITH THE RESULTING TREATED SAND PORTION FROM ABOUT 5 TO ABOUT 20 PERCENT BY WEIGHT OF A GUANIDINE SALT IN A POLAR OXYGENATED ALIPHATIC HYDROCARBON SOLVENT, AND MAINTAINING SAID GUANIDINE SALT IN CONTACT WITH THE SAND PORTION OF THE FORMATION FOR A TIME PERIOD SUFFICIENT TO EFFECT STABILIZATION OF SAID SAND PORTION.

Claim 2

A METHOD OF TREATING A WATER-SENSITIVE SANDCONTAINING FORMATION TO IMPROVE THE WATER PERMEABILITY OF THE SAND PORTION WHICH COMPRISES IN COMBINATION INJECTING INTO SAID FORMATION AND INTO CONTACT WITH SAID SAND PORTION THEREOF, AT AN ELEVATED TEMPERATURE AND A SUPERATMOSPHERIC PRESSURE, STEAM IN AN AMOUNT SUFFICIENT TO PROVIDE FROM ABOUT 0.1 TO ABOUT 10 PERCENT BY VOLUME THEREOF PER PORE VOLUME OF SAID SANDY PORTION OF THE FORMATION, THEREAFTER INJECTING INTO SAID FORMATION AND INTO CONTACT WITH THE RESULTING TREATED SAND PORTION FROM ABOUT 5 TO ABOUT 20 PERCENT BY WEIGHT OF A GUANIDINE SALT IN A POLAR OXYGENATED ALIPHATIC HYDROCARBON SOLVENT, AND MAINTAINING SAID GUANIDINE SALT IN CONTACT WITH THE SAND PORTION OF THE FORMATION FOR A TIME PERIOD SUFFICIENT TO EFFECT STABILIZATION OF SAID SAND PORTION.

Claim 9

A method of recovering oil from an oil-bearing underground formation containing a water sensitive sand portion, wherein a displacement fluid is applied to said formation and oil is recovered therefrom which comprises first contacting said sand at an elevated temperature and pressure with from about 0.01 to about 10 percent by volume, per pore volume of said sand portion, of steam to effect water removal therefrom, then bringing a treating solution consisting of guanidine salt in a polar oxygenated aliphatic hydrocarbon solvent into contact with said treated sand portion for a time period sufficient to stabilize the sandy portion against water sensitivity and thereafter introducing a displacement fluid into said formation under pressure to force said treating solution through the formation and recovering oil from said formation.

Claim 10

A method of recovering oil from an oil-bearing underground formation containing a water sensitive sand portion, wherein a displacement fluid is applied to said formation and oil is recovered therefrom which comprises first contacting said sand at an elevated temperature and pressure with from about 0.01 to about 10 percent by volume, per pore volume of said sand portion, of steam to effect water removal therefrom, then bringing a treating solution consisting of guanidine salt in a polar oxygenated aliphatic hydrocarbon solvent into contact with said treated sand portion for a time period sufficient to stabilize the sandy portion against water sensitivity and thereafter introducing a displacement fluid into said formation under pressure to force said treating solution through the formation and recovering oil from said formation.