Gel and process for preventing loss of circulation, and combination process for enhanced recovery

Patent · Tue Feb 17 04:00:00 EST 1987

OSTI ID:6759325

Sandiford, B B; Zillmer, R C

A process is described for reducing the loss of circulation fluids into flow passages of a subterranean formation during well drilling, completion, or workover operations, the circulation fluids being selected from the group consisting of drilling fluids, completion fluids and workover fluids. The process comprises: (a) stopping the injection of a circulation fluid selected from the group consisting of drilling fluids, completion fluids and workover fluids into a wellbore; (b) introducing into the flow passages, an effective amount of a gel-forming composition comprising i. an aqueous solution comprising a first substance selected from the group consisting of polyvinyl alcohols, polyvinyl alcohol copolymers, and mixtures thereof, ii. an amount of an aldehyde, and iii. an amount of a crosslinking catalyzing substance, which in combination with the aqueous solution and the aldehyde is operable for effecting gelation, at the temperature of the subterranean formation, of the gel-forming composition in a period of time no greater than about 12 minutes after being introduced into the subterranean formation; and (c) allowing the gel-forming composition to enter into the flow passages and to form a gel therein within the period of time mentioned in step (b), thereby reducing the loss of the circulation fluid upon resuming well drilling, completion or workover operation.

• Assignee: Cities Service Oil and Gas Corp., Tulsa, OK
• Patent Number(s): US 4643255
• OSTI ID: 6759325
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
ALCOHOLS
ALDEHYDES
AQUEOUS SOLUTIONS
CATALYSIS
CHEMICAL REACTIONS
COPOLYMERS
CROSS-LINKING
DISPERSIONS
DISPLACEMENT FLUIDS
DRILLING
DRILLING FLUIDS
ENERGY SOURCES
ENGINEERING
ENHANCED RECOVERY
FLUID INJECTION
FLUIDS
FOSSIL FUELS
FUELS
GELATION
HYDROXY COMPOUNDS
LOST CIRCULATION
MIXTURES
OIL WELLS
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PETROLEUM
POLYMERIZATION
POLYMERS
POLYVINYLS
PVA
RECOVERY
RESERVOIR ENGINEERING
SOLUTIONS
STIMULATION
TEMPERATURE DEPENDENCE
TIME DEPENDENCE
WELL COMPLETION
WELL DRILLING
WELL STIMULATION
WELLS