TO BUILD UP A COMPUTATION MODEL ON FRICTION LOSS IN FOAM FRACTURING

Foam fracturing has been widely used in the recovery of peculiar reservoirs with low pressure, low permeability, and water sensitivity, because of its obviously good results such as less damage on the formations, quick flowback, little filtration, high viscosity, small friction resistance, and high proppant carrying capacity, etc. Compared with regular fracturing fluids, foam fracturing fluids show differences in two ways: first, the fracture fluid is compressible, its density is well depth's function and its friction coefficient is changed accordingly due to the existence of gas phase in foam fracture; second, since foam fracture fluid can flow not only in single phase but in multiphase in borehole, the calculating method on friction of traditional fracture fluid is not suitable to foam fracture fluid any more. As a result, the calculating model on friction loss during foam fracture was established. In this model, the resolution method of friction coefficient was modified in accordance with the theory of volume identity and also was illustrated by a case of study in a certain selected well with foam fracturing.