摘要 |
Methods of sealing particular areas, including subterranean well formations, are provided wherein the methods utilize an isocyanate polymer suitable as a sealing agent having a controllable gelation time in the presence of water without formation of excess foam by using one or more typical di- or polyisocyanates with one or more alcoholic or acidic compounds and a particular catalyst namely, triethylene-diamine, Groups 3 and 4 metal-organic compounds or mixtures thereof. A particularly useful catalyst is tributyl titanate.
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