초록 ▼

A nondamaging work over and completion fluid having water soluble bridging agents includes a saturated brine solution having at least one water soluble salt which is insoluble in the saturated brine solution and having particle size range of about 5 microns to about 800 microns and wherein greater t

A nondamaging work over and completion fluid having water soluble bridging agents includes a saturated brine solution having at least one water soluble salt which is insoluble in the saturated brine solution and having particle size range of about 5 microns to about 800 microns and wherein greater than about 5% of the particles are coarser than 44 microns. Viscosifier and suspension additive is added to provide the desired viscosity and assist in maintaining the water soluble sized salt suspended in the saturated brine solution. If desired or necessary a fluid loss control agent may be added to enhance the fluid loss control or filtration control of the completion fluid. The invention may be practiced by pumping or discharging the fluid or a slug or pill of the fluid into an oil, gas, water, injection or storage well where operations are to be conducted in which it is desired to temporarily plug the permeable zone while such operations are carried out. Thereafter, the water soluble bridging agents are removed by connate water from the permeable zone, or a nonsaturated brine wash, or ordinary water circulated in the well.

대표청구항 ▼

A well completion and work over fluid consisting essentially of: a. a saturated brine solution consisting of any of the group of potassium chloride, sodium chloride, calcium chloride, sodium sulfate, sodium carbonate, sodium bicarbonate, calcium bromide and potassium carbonate; b. a bridging agent c

A well completion and work over fluid consisting essentially of: a. a saturated brine solution consisting of any of the group of potassium chloride, sodium chloride, calcium chloride, sodium sulfate, sodium carbonate, sodium bicarbonate, calcium bromide and potassium carbonate; b. a bridging agent consisting of at least one water soluble sized salt which is insoluble in the saturated brine solution, said sized water soluble salt having a particle size in the range of approximately 5 microns to approximately 800 microns and wherein greater than about 5% of the particles are coarser than 44 microns; c. the sized soluble salt that is insoluble in the saturated brine solution consisting of any of the group of potassium chloride, sodium chloride, calicum chloride, sodium sulfate, sodium carbonate, sodium bicarbonate, calcium bromide and potassium carbonate in the amount of approximately 4 pounds per barrel to about 50 pounds per barrel of saturated brine solution; and d. a viscosifier and suspension additive in the amount of about 0.2 pound per barrel of saturated brine solution to about 5 pounds per barrel of saturated brine solution.