| 摘要 |
A process for the selective gelation of a polymer for profile control during carbon dioxide flooding. First, a size selective gel is formed ex-situ. Upon entering a thief zone or a more permeable low pH zone resultant from carbon-dioxide flooding, the gel forms a solid, firm gel. This gel comprises an aqueous composition of a partially and fully alkylated melamine resin and an xanthan polymer. Size selectivity is imparted by the partially alkylated resin and the polymer. Upon contact with the low pH environment, active melamine resin is released from the fully alkylated resin which reacts with the polymer to form a stable, solid gel. Once the solid gel has formed, steam-flooding, water-flooding or a carbon-dioxide oil recovery process is commenced in a zone where a solid gel has not formed.
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