Method to increase sand grain coating coverage

A composition useful as a preflush fluid used prior to introducing a sand consolidation fluid, said composition comprising:

• a) 20-80% by weight of an alkyl ester having 1 to 6 carbons;
• b) 80-20% by weight of a monomer or oligomer of a resin selected from furfural and furfuryl alcohol;
• and
• c) 0-5% by weight of a coupling agent selected from the group consisting of silanes, titanates and zircoaluminumates.

A method for consolidating unconsolidated mineral particles with a resin in a subterranean petroleum formation, the formation being penetrated by a well which forms a fluid communication between a point on the surface and at least a portion of the formation, the method comprising:

• introducing into the formation an effective amount of a preflush, said amount of preflush being sufficient to invade substantially all of the pore spaces of a portion of the formation to be consolidated, wherein said preflush comprises an oligomer or monomer of the resin to be used in the sand consolidating fluid, and a diluent for the oligomer or monomer of the resin;
• introducing a sand consolidating fluid into substantially the same portion of the formation as the preflush fluid, wherein the sand consolidating fluid comprises a polymerizable compound, a diluent for the polymerizable compound and an acid catalyst capable of causing condensation polymerization of the compound at fluid injection temperatures,
• introducing an aqueous saline solution into substantially the same portion of the formation as the sand consolidating fluid, and
• allowing the sand consolidating fluid to remain in the formation for a period of time sufficient to accomplish at least partial polymerization, forming a permeable consolidated mass around the wellbore.