Patent ID: 6325149
Filing Date: 2001-12-04
Classification: C09K,E21B

Abstract:
A method of decreasing the loss of fluid to a hydrocarbon producing formation during workover or completion operations which comprises pumping a solids-free, viscous, fluid loss control fluid to the location in a borehole where the workover or completion operation is to be conducted, wherein the solids-free, viscous, fluid loss control fluid comprises an aqueous liquid comprising a solution of one or more soluble bromide salts having dissolved therein one or more polyethylene glycols having an average molecular weight from about 1,000 to about 8,000,000, wherein the minimum concentration of the polyethylene glycol in the fluid varies with the average molecular weight as follows: MW=1,000 to 10,000=100 ppb; MW=10,001 to 100,000=75 ppb; MW=100,001 to 250,000=50 ppb; MW=250,001 to 500,000=10 ppb; MW=500,001 to 8,000,000=5 ppb.