Patent ID: 9429006
Filing Date: 2016-08-30
CPC Classification: C09K,E21B

Claim Text:
1. A method of hydraulically fracturing a subterranean formation comprising: pumping into the formation at least two stages wherein a first stage is a proppant-free and a second stage is a proppant laden wherein: (a) either the first stage or second stage contains a breaker; (b) each of the stages contains at least one viscosifying agent, wherein the viscosifying agent is a superabsorbent polymer, a synthetic polymer or a viscoelastic surfactant and further wherein (i) the synthetic polymer is other than a superabsorbent polymer; (ii) at least one of the stages contains at least one superabsorbent polymer; and (iii) the breaker has less affinity for the viscosifying agent in the stage containing the breaker than the viscosifying agent of the other stage; and degrading the viscosifying agent in the stage not containing the breaker with the breaker at in-situ reservoir conditions.