Formation fracturing process

In a process for fracturing a subterranean formation penetrated by a wellbore wherein a fracture treatment fluid comprising an aqueous gel is pumped down said wellbore and into said formation at formation fracturing pressure, wherein a fluid loss control material is included in said treatment fluid, and wherein a gel filter cake is formed on the surfaces of said wellbore and the fractures in said formation, the improvement comprising:

• utilizing as at least a part of said fluid loss control material a hydroxyacetic acid condensation product, said condensation product being degradable at formation conditions whereby hydroxyacetic acid monomers and dimers are formed, and said condensation product being present in an amount sufficient to provide enough degradation products including hydroxyacetic acid to react with and break the gel in said filter cake and to recover permeability in said formation and fractures without the necessity of adding a separate gel breaking material after formation of said gel filter cake.