Pillar Fracturing

A method of hydraulic fracturing, comprising:

• providing a foam fracturing fluid through a wellbore into a subterranean formation;
• hydraulically fracturing the subterranean formation with the foam fracturing fluid, thereby generating fractures in the subterranean formation;
• conveying proppant in the foam fracturing fluid through the wellbore into the fractures;
• and
• forming pillars of proppant in the fractures by intermittently adjusting a property of the foam fracturing fluid conveying the proppant.

A method of hydraulic fracturing with a viscoelastic surfactant (VES)-based fracturing fluid, comprising:

• pumping the VES-based fracturing fluid through a wellbore into a subterranean formation;
• hydraulically fracturing the subterranean formation with the VES-based fracturing fluid, thereby generating fractures in the subterranean formation;
• conveying proppant in the VES-based fracturing fluid through the wellbore into the fractures;
• and
• intermittently altering rheology of the VES-based fracturing fluid conveying the proppant to form pillars of proppant in the fractures.

A system for hydraulic fracturing, comprising:

• a source of fracturing fluid;
• a pump operationally coupled to the source to provide the fracturing fluid through a wellbore into a subterranean formation to hydraulically fracture the subterranean formation to generate fractures in the subterranean formation, wherein the fracturing fluid to convey proppant into the fractures;
• and
• a control system to intermittently adjust a characteristic of the fracturing fluid conveying the proppant to form pillars of proppant in the fractures.