PRACTICAL CONSIDERATIONS FOR FRACTURE TREATMENT DESIGN 700 \ 600 500 \ \ \ 25Q 400 \ \ 50Q 300 200 100 0 0 1 2 3 4 5 Time (hr) Figure P-25-Apparent viscosity for crosslinked 40 Ib/lOOO gal foams at 170 sec-’ and 150°F. P- 23