摘要 |
NITROGEN STIMULATION OF A POTASSIUM HYDROXIDE WELLBORE TREATMENT Clays in water sensitive subterranean formations are stabilized by injecting a sufficient amount of an inert gas, preferably nitroyen, into the formation to substantially fluidize the clays (including migratible fine particles), thereafter injecting into the formation an aqueous solution of soft water and potassium chloride to effect a cationic exchange between the potassium and the sodium within the clays and then injecting into the formation an aqueous solution of soft water and potassium hydroxide. The potassium hydroxide renders the clays relatively insensitive to an aqueous solution having an ionic makeup distinct from connate waters within the formation, thus, this process protects against formation damage by a "fresher" water, The well can be an injection well or a production well.
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