| abstract |
Crosslinked gelling agents employed during subterranean operations use electronically-modified boronic acids to enable higher operating temperatures while allowing reduced gelling agent loadings; the boronic acids having Formula I: X1 and X2 are independently selected from O, CH2, CH2O, OCH2, bond, and null, Y1 and Y2 are independently N or C, Ar is a 5- or 6-membered ring aryl or heteroaryl group with a link L to monomer unit M1, m is 1 or 2, n is 0, 1, 2, or 3, and each Z is independently an electron withdrawing group selected from nitro, ester, carboxylic acids, carboxylates, halogen, cyano, amide, acyl, alkylsulfonyl, arylsulfonyl, heteroarylsulfonyl, CF3, a quaternary ammonium salt, polyhaloalkyl, and carbamate, with the proviso that when n is 0, the link L between M1 and Ar includes an electron withdrawing group attached to Ar, and introducing the treatment fluids into subterranean formations. |