An experimental study of the in-situ gelation of chromium(+3)/polyacrylamide polymer in porous media
Gelled polymers are being used increasingly as reservoir flow control agents to improve the water-to-oil ratio (WOR) in waterflooding. To date, little has been published in the literature on the in-situ gelation of polymers in porous media. This work was undertaken to study the process of in-situ gelation of a gel system consisting of a polyacrylamide polymer, sodium dichromate, and thiourea. The experiments consisted of continuous injection of gel solutions into 1-ft (0.3-m) unconsolidated sandpacks. Pressure distributions along the flow direction were used to interpret the nature of gelation in the porous media. The authors found the gelation occurred much earlier than anticipated from beaker tests where gel solutions were under conditions of no shear-e.g., a gel solution with a nominal 10-day gel time in a beaker gelled in 85 hours in a porous-medium run. Shear was considered one of the major factors affecting the in-situ shear rate, and we determined that gelation times decreased with increasing in-situ shear rates. Under the same in-situ shear rate, the in-situ gelation times were approximately equal in sandpacks prepared from different grain sizes. The order in which in-situ gelation occurred along the flow direction indicated that the shear history affected gelation time. Effluents from displacements with gel solutions were analyzed to evaluate the change in the properties of a gel solution as it moved through the porous media. The chemical analysis indicated that the retention of polymer was marked after the in-situ gelation developed.
- Research Organization:
- China Technical Consultants Inc.
- OSTI ID:
- 7053014
- Journal Information:
- SPE (Society of Petroleum Engineers) Reserv. Eng.; (United States), Journal Name: SPE (Society of Petroleum Engineers) Reserv. Eng.; (United States) Vol. 1:6; ISSN SREEE
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
020300* -- Petroleum-- Drilling & Production
ADDITIVES
ALKALI METAL COMPOUNDS
CARBONIC ACID DERIVATIVES
CHEMICAL ANALYSIS
CHROMATES
CHROMIUM COMPOUNDS
COLLOIDS
DISPERSIONS
ENERGY SOURCES
ENHANCED RECOVERY
FLUID INJECTION
FOSSIL FUELS
FUELS
GELATION
GELS
IN-SITU PROCESSING
MICROEMULSION FLOODING
MISCIBLE-PHASE DISPLACEMENT
OIL WELLS
ORGANIC COMPOUNDS
ORGANIC POLYMERS
ORGANIC SULFUR COMPOUNDS
OXYGEN COMPOUNDS
PETROLEUM
POLYAMIDES
POLYMERS
POROSITY
PRESSURE MEASUREMENT
PROCESSING
RECOVERY
RESEARCH PROGRAMS
SHEAR
SODIUM COMPOUNDS
STIMULATION
THIOUREAS
TRANSITION ELEMENT COMPOUNDS
WATERFLOODING
WELL STIMULATION
WELLS