Heat-guided hydroxide plugging

Claim 2

The process of claim 1 in which the temperature within said region is adjusted by injecting hot fluid from a location remote from the location from which said plug-forming liquid is injected.

Claim 3

The process of claim 1 in which the temperature within said region is adjusted by injecting a relatively cool fluid.

Claim 4

The process of claim 1 in which said plug-forming liquid is injected in the form of a slug which is kept static within said region until plugging has occurred within said hotter portions.

Claim 5

The process of claim 1 in which a stream of said plug-forming liquid is displaced through said region at a rate providing a resident time for each increment that is sufficient to cause plugging within said hotter portions but insufficient to cause plugging within said cooler portions.

Claim 6

In a process of producing oil from a subterranean reservoir by operating at least one pair of injection and production wells to flow hot oil-displacing fluid within said reservoir while producing fluid from the reservoir, an improved process for continuing said oil production after said hot oil-displacing fluid begins to flow into at least one production well, comprising: interrupting fluid production from a production well into which said inflow of hot fluid has occurred and injecting into the near well region around said well a plug-forming liquid that reacts to deposit a plugging material faster in the hotter portions than in the cooler portions of said region; displacing unreacting plug-forming liquid from the cooler portions of said region after plugging has occurred in the hotter portions; and returning said production well to the production of fluid.

Claim 7

The process of claim 7 in which said plug-forming liquid comprises an aqueous solution of a metal that is adapted to precipitate as a gelatinous metal hydroxide mixed with a reactant that increases the pH of the aqueous solution to cause said precipitation.

Claim 8

The process of claim 8 in which said injection of plug-forming liquid is preceded by injection of relatively cool fluid to transport heat from within the borehole to within the reservoir.