摘要 |
The present application describes improved compositions for wellbore fluids for use in downhole (e.g. oilwell) applications. The compositions comprise a blocked isocyanate (BI) component having a tolerance improving group (such as a hydrophilic group, e.g. an amine) bonded to it, and an active hydrogen component. When the BI group is unblocked, it reacts with the active hydrogen component to form a gel which, by virtue of the tolerance improving group, is more tolerant to contaminants (such as aqueous inorganic salts or brines) than the corresponding gel forms from unmodified BI. The application also relates to methods of treating an earthen formation using such a composition. |