Restoring permeability to water-damaged pays
Clay swelling in consolidated rocks contacted with fresh water is a troublesome phenomenon. For producers, the most serious aspect of the problem is the reduction in flow rate from wells affected by this malady. In some cases, contact of the clay-bearing formation with fresh water completely destroys permeability, blocking all flow into the well bore. The effect of multivalent ions on clays is discussed, and what must be done to the system to shrink such clays, based on laboratory tests, is examined. From the information presented, it can be seen that treatment of the clay with a solution of Ca++ ion or other multivalent ion will prevent the clay from swelling in the presence of fresh water. If the fresh water has already contacted the formation (or is present as connate water), simple treatment with calcium chloride is not sufficient. This study indicates that improvement in permeability can be obtained from the calcium-chloride treatment, if the formation can be dried after the treatment. A suggestion is made that the formation may be dried in the well bore, by the injection of nitrogen or the use of heat with or without gas injection. Once the clay has been shrunk by drying, then some permeability benefits may be expected from the calcium-chloride treatment.
- Research Organization:
- Pennsylvania State Univ
- OSTI ID:
- 5666232
- Journal Information:
- Oil Gas J.; (United States), Journal Name: Oil Gas J.; (United States) Vol. 68:5; ISSN OIGJA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
020300* -- Petroleum-- Drilling & Production
ALKALINE EARTH METAL COMPOUNDS
CALCIUM CHLORIDES
CALCIUM COMPOUNDS
CALCIUM HALIDES
CHLORIDES
CHLORINE COMPOUNDS
CLAYS
ENERGY SOURCES
FLUID INJECTION
FOSSIL FUELS
FRESH WATER
FUELS
GAS INJECTION
HALIDES
HALOGEN COMPOUNDS
HYDROGEN COMPOUNDS
OIL WELLS
OXYGEN COMPOUNDS
PERFORMANCE
PERMEABILITY
PETROLEUM
PLUGGING
RESERVOIR ROCK
STIMULATION
SWELLING
WATER
WELL COMPLETION
WELL SERVICING
WELL STIMULATION
WELLS