| 摘要 |
Many petroleum formations contain water having excessive quantities of salt or divalent ions such as calcium or magnesium dissolved therein, and are additionally at a temperature from about 70 DEG to about 300 DEG F. Most surfactants otherwise usable for oil recovery operations are either ineffective in high salinity or hard water, or decompose or precipitate at the higher temperature encountered in formations. A sulfonated, ethoxylated alcohol or alkylphenol surfactant, either as the sole constituent of the surfactant solution, or as a co-surfactant with a more conventional anionic surfactant such as petroleum sulfonate, alkyl sulfonate, or alkylaryl sulfonate, is effective for use in formations containing water having substantial amounts of salt and/or divalent ion salts such as calcium or magnesium dissolved therein, and which additionally may be hotter than 120 DEG F.
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