Abstract: An aqueous solution comprising a thickening polymer with diol groups distributed along it, such as guar or other polysaccharide, is cross linked with a cross-linker which contains a plurality of boroxole groups of the partial formula wherein R1 is hydrogen or a substituent group or an attachment to the remainder of the cross-linker molecule, R2 is hydrogen or a substituent group, R3 is hydrogen or an aliphatic or aromatic group and the carbon atoms joined by a double bond are part of an aromatic ring. The thickened fluid may be a wellbore fluid and may be a hydraulic fracturing fluid in which a particulate proppant is suspended.

Abstract: The addition of specific fibrous, platelet, and/or fibrous and platelet compositions in mixtures with particulates for or during well treatment procedures such as fracturing and gravel packing decreases or eliminates the undesirable transport or flowback of proppant or formation particulates. Novoloid and novoloid-type polymer material may be used for forming a porous pack in a subterranean formation.