摘要 |
A sand consolidation method is provided for use in a borehole having an unconsolidated or loosely consolidated oil or gas reservoir which is likely to introduce substantial amounts of sand into the borehole and cause caving. After perforating the borehole's casing at an interval of the formation where sand will be produced, an aqueous silicate solution is injected into said interval. Next, a spacer volume of a water-immiscible hydrocarbonaceous liquid is introduced into the interval. Thereafter, a water-miscible organic solvent containing an alkylpolysilicate is injected into the interval. A permeability retaining silica cement is formed in the interval. Injection of the aqueous silicate and organic solvent containing an alkylpolysilicate is continued until the interval has been consolidated by the silica cement to an extent sufficient to prevent sand migration and thereby prevent caving.
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