Sheath encapsulation to convey acid to formation fracture

A method comprising:

• firing, by a perforating gun, a plurality of shaped charges at a depth in a wellbore formed in a subterranean zone to form a plurality of perforations in the wellbore to provide access to the subterranean zone at the depth;
• responsive to firing the plurality of shaped charges, releasing, by a sheath carrying powdered acid and encapsulating the perforating gun, the powdered acid onto the subterranean zone through the plurality of perforations, wherein the powdered acid reacts with and weakens the subterranean zone at the depth to ease flow of hydraulic fracturing fluid into the subterranean zone at the depth;
• and
• flowing the released powdered acid into the subterranean zone at the depth after releasing the powdered acid responsive to firing the plurality of shaped charges, wherein the released powdered acid is flowed into the subterranean zone by mixing the released powdered acid with a fluid flowed from a surface of the wellbore into the subterranean zone at the depth.

A method comprising:

• filling an internal chamber defined by a sheath with powdered acid that is configured to react with a subterranean zone when applied to the subterranean zone to weaken the subterranean zone to ease flow of hydraulic fracturing fluid into the subterranean zone;
• encapsulating the sheath around a perforating gun comprising a plurality of shaped charges configured to be fired to form a plurality of perforations in a wellbore formed in the subterranean zone;
• lowering the perforating gun encapsulated by the sheath to a depth within the wellbore;
• triggering the perforating gun to fire the plurality of shaped charges causing the plurality of perforations to be formed in the wellbore and causing the powdered acid to be released onto the subterranean zone at the depth through the plurality of perforations;
• and
• after triggering the perforating gun, flowing additional fluid into the wellbore to flow the released powdered acid into the subterranean zone through the plurality of perforations.