Why can't seawater be used for fracking?

It can be used, depending on the reservoir chemistry. Sometimes there are minerals in the reservoir rock that don't play nice with the minerals dissolved in seawater. read more

We don't always use fresh water for drilling and fracking but, as Ryan said, the water issue is mostly propaganda. Fracking hasn't depleted the Ogallala, tens of thousands of irrigation pumps have. We have salt water gels so, we can suspend sand in salt water and use it in fracks. read more

In places where frakking is occurring near the ocean (California, for example), sea water is reportedly used. In other places where fresh water is very scarce, oil is cheap, and the sea is very close, sea water IS apparently used in oil recovery, like seawater injection into the Ghawar field to maintain pressure. That isn't fracking, though. read more

Fracking with seawater is not new and done lots of times in offshore environment. CO2 and N2 can be used as additives to frac fluid to energize it or create foam but can't substitute it. read more