A gelable composition is provided which can be injected into a well prior to steam treatment of the well. The composition comprises water, a water-dispersible polymer, a water-dispersible first crosslinker and a water-dispersible second crosslinker, wherein the first and second crosslinkers have differing temperature responsive crosslinking characteristics over the temperature range of about 70.degree. F. to about 400.degree. F. so as to enable crosslinking of the polymer and gelation of the composition over substantially the entire temperature range. Injection of the composition into a "cold" well followed by steam treatment of the well causes the polymer to undergo a two stage crosslinking reaction which produces a particularly effective and stable gel in diverting steam from "thief zones" in the formation surrounding the well.