399 727 which issued to graham et al on sept 3 1968 this patent is hereby incorporated by reference herein as is preferred the specific gravity of the proppant will be from about 0 4 to about 1 2 gm cc in practising the invention silica oxides glass or other ceramic proppants are added to the fracturing fluid in a concentration in excess of 10 pounds per gallon preferably 10 12 pounds per gallon once in the fracturing fluid the proppant laden fluid is injected into a well in accordance with known fracturing procedures using conventional equipment injection of the 34 pad 34 is continued until a fracture of sufficient geometry is obtained to permit placement of the proppant particles normally the treatment is designed to provide a fracture width at the wellbore of at least 2 and 1 2 times the diameter of the largest propping agent particle once the fracture of desired geometry is obtained the propping agent suspended in the fluid is carried and placed into the fracture following the placement of the proppant the well is shut in for a time sufficient to permit the pressure to bleed off into the formation this causes the fracture to close and exert a closure stress on the propping agent particles the shut in period may vary from a few.