In hydraulic fracturing, the temperature at which a polymer is to be used determines the break mechanism and the breaker used for its degradation. The polymers most commonly used in fracturing were degraded under a variety of conditions and their resulting flow impairment characteristics were measured in 20/40 mesh sandpacks. Enzyme breaker was used for the low temperature tests (120°F), oxidizing breaker was used for the intermediate temperature tests (180°F) and thermal degradation processes were used for the high temperature tests (275° – 400°F).
The polymers evaluated were derivatized cellulose (0% w/w residue), derivatized guar gum (1-2% w/w residue), intermediate residue guar gum (5-6% w/w residue) and guar gum (8-10% w/w residue). The relative residue volumes for these polymers were determined and compared to their actual flow impairment values. The effect of polymer loading on the relative flow impairment was also determined for these polymers as a function of break temperature.