Oil recovery with water containing carbonate salt and CO/sub 2/
In a process in which a mixture of an aqueous liquid and CO/sub 2/ is injected into a subterranean reservoir, an improvement is described for reducing the adverse effects of the resultant carbonic acid, which consists of: dissolving in the aqueous liquid with which the CO/sub 2/ is mixed, an amount of monovalent cationic salt of carbonic acid sufficient for providing a pH of at least about 4 but is less than enough to cause precipitation of carbonate salts at the pressure and temperature of the reservoir; and injecting the preformed mixture into the reservoir. A process is also described for preparing a brine solution in which divalent cations are present, that solution being effective for increasing the pH of the brine solution under reservoir conditions in a CO/sub 2/ flooding operation comprising: maintaining a blanket of CO/sub 2/ on the brine solution; and dissolving in the brine solution an amount of monovalent cationic carbonic acid salt which is sufficient to increase the brine solution pH under reservoir conditions and effective to reduce adverse mineral transformations within the reservoir.
- Assignee:
- Shell Oil Co., Houston, TX
- Patent Number(s):
- US 4762178
- OSTI ID:
- 7027786
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
020300* -- Petroleum-- Drilling & Production
AQUEOUS SOLUTIONS
BRINES
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CARBONATES
CARBONIC ACID
CHALCOGENIDES
CHEMICAL COMPOSITION
CHEMICAL PREPARATION
DISPERSIONS
DISPLACEMENT FLUIDS
ENERGY SOURCES
ENHANCED RECOVERY
FLUID INJECTION
FLUIDS
FOSSIL FUELS
FUELS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
MIXTURES
OIL WELLS
OXIDES
OXYGEN COMPOUNDS
PETROLEUM
RECOVERY
SOLUTIONS
STIMULATION
SYNTHESIS
WELL STIMULATION
WELLS