High solids content methods and slurries

A method, comprising:

• combining a carrier fluid and a solids mixture to form a flowable slurry, wherein the solids mixture comprises a plurality of volume-averaged particle size distribution (PSD) modes, wherein a first PSD mode comprises solids having a volume-average median size at least three times larger than the volume-average median size of a second PSD mode such that a packed volume fraction (PVF) of the solids mixture exceeds 0.75, and wherein the solids mixture comprises a degradable material and includes a reactive solid;
• circulating the slurry through a wellbore to form an accumulation of the solids mixture having a PVF exceeding 0.75 in one or both of a fracture in a formation and an annulus between a screen and the wellbore;
• degrading the degradable material in the accumulation to increase porosity and permeability of the accumulation;
• and
• producing a reservoir fluid from the formation through the increased porosity accumulation.