Stimulation results in the low-permeability Wasatch formation - an evolution to foam fracturing

The Wasatch Formation of the Uinta Basin in E. Utah is typical of many formations in the Rocky Mt., having low permeability and high sensitivity to water. Stimulation treatments with several types of fracturing fluids, including oil-water emulsion fluids, complex gel fluids and foam fluids, generally have been successful. Production decline curves from 24 wells in the field were used for comparison of the different stimulation methods. Although foam fracturing has been used for the shortest period of time, comparison of the production histories show the relatively higher efficiency of the foam fracturing treatments compared to other stimulation methods in the Wasatch Formation. Foam fluids gave higher production rates and higher flowing pressures than offset wells fractured with complex gel fluids.