Repair of channels between well bores

Claim 1

IN A SECONDARY RECOVERY OF HYDROCARBONS FROM A SUBSURFACE EARTH FORMATION WHEREIN A FLUID IS INJECTED INTO THE FORMATION THROUGH A FIRST WELL BORE AND CONNATE EARTH FLUIDS ARE WITHDRAWN THRUGH A SECOND WELL BORE SPACED APART THEREFROM, A METHOD OF REPAIRING THE FORMATION WHEN A CHANNEL THEREIN PERMITS DIRECT FLUID COMMUNICATION BETWEEN THE WELL BORES, COMPRISING: FORMING A FLUID HAVING AN APPARENT VISCOSITY OF AT LEAST 30 CENTIPOISES AND A WATER LOSS OF NOT MORE THAN 20 CC. API; PUMPING A QUANTITY OF SAID FLUID INTO SAID CHANNEL THROUGH SAID FIRST WELL BORE AHEAD OF A CEMENTITIOUS MIXTURE HAVING A WATER LOSS OF GREATER THAN 20 CC. API; MEASURING THE QUANTITY OF SAID FLUID AND OF SAID CEMENTITIOUS MIXTURE PUMPED INTO SAID CHANNEL; DETECTING THE ARRIVAL OF SAID FLUID AT A PREDETERMINED LOCATION IN SAID SECOND WELL BORE TO DETERMINE THE VOLUME OF THE CHANNEL; AFTER DETECTION OF SAID FLUID, PUMPING SAID CEMENTITIOUS MIXTURES INTO SAID CHANNEL UNTIL SAID FLUID IS DISPLACED FROM SAID CHANNEL AND THE CEMENTITIOUS MIXTURE SUBSTANTIALLY FILLS THE CHANNEL; AND DELAYING SUBSEQUENT INJECTION OF SECONDARY RECOVERY FLUID INTO SAID FORMATION THROUGH SAID FIRST WELL BORE UNITL THE CEMENTITIOUS MIXTURE HAS HARDENED.