Hydrated metal oxide deposition

Claim 2

A DRILLING FLUID FILTRATE-EFFECTED SAND CONSOLIDATING DRILLING PROCESS COMPRISING: DRILLING A BOREHOLE INTO A PERMEABLE GRANULAR SUBTERRANEAN EARTH FORMATION WHILE CIRCULATING AN AQUEOUS DRILLING FLUID THAT CONTAINS AN AQUEOUS SOLUTION OF AN AMPHOTERIC METAL OXIDE AND A PH REDUCING REACTANT ADAPTED TO LOWER THE PH OF THE SOLUTION TO ONE AT WHICH A HYDRATE METAL OXIDE IS PREDIPITATED AND SUSPENSION RELATIVELY FINELY DIVIDED SOLID PARTICLES ADAPTED TO FORM A FLUID LOSS CONTROLLING FILTER CAKE ON A PERMEABLE EARTH FORMATION; AND PRESSURIZING SAID CIRCULATING DRILLING FLUID WITHIN THE BOREHOLE SO THAT SAID PERMEABLE EARTH FORMATION IS INVADED BY THE SOLUTION FROM WHICH A HYDRATED METAL OXIDE IS SUBSEQUENTLY PRECIPITATED.

Claim 3

The process of claim 1 in which said amphoteric metal oxide is an aluminum oxide.

Claim 4

The process of claim 1 in which: said aqueous drilling fluid containing an amphoteric metal oxide is formed near a well site at which a borehole is being drilled with an aqueous drilling fluid; and after said borehole has been advanced to a depth near an unconsolidated subterranean reservoir interval the composition of the drilling fluid being circulated in said borehole is altered by mixing with said aqueous drilling fluid being circulated an amphoteric metal material adapted to interact with a basic aqueous liquid to form an aqueous solution of a hydroxy complex of the amphoteric metal, at least one basic material adapted to increase the pH of an aqueous liquid to a pH adapted to dissolve said hydroxy complex and a pH reducing reactive material adapted to dissolve in a basic aqueous solution of said hydroxy complex and subsequently reduce the pH of the solution to one at which a hydrated metal oxide of the amphoteric metal is precipitated, so that said aqueous drilling fluid being circulated is converted to said amphoteric metal oxide containing drilling fluid.

Claim 5

The process of claim 1 in which said drilling fluid pressurization-induced invasion of fluid into a borehole-encountered earth formation is continued until the permeability of the invaded portion of the earth formation is significantly reduced.

Claim 6

A process of drilling a well borehole while consolidating an unconsolidated earth formation encountered by the borehole, comprising: operating an earth formation drilling means while circulating an earth formation solids-removing fluid to advance a borehole into an unconsolidated earth formation; and circulating as said solids-removing fluid a fluid that contains a relatively high pH aqueous solution of an amphoteric metal oxide and a pH reducing reactant material, which solution is adapted to penetrate into and effect a single step and single fluid treatment consolidation of an unconsolidated earth formation.

Claim 7

A process of drilling a well borehole while consolidating an unconsolidated earth formation encountered by the borehole, comprising: operating an earth formation drilling means while circulating an earth formation solids-removing fluid to advance a borehole into an unconsolidated earth formation; and circulating as said solids-removing fluid a fluid that contains a relatively high pH aqueous solution of an amphoteric metal oxide and a pH reducing reactant material, which solution is adapted to penetrate into and effect a single step and single fluid treatment consolidation of an unconsolidated earth formation.

Claim 8

The process of claim 5 in which the circulating solids removing fluid contains a fluid-loss preventing agent that is arranged to allow a significant amount of fluid loss into permeable earth formations.