Large scale and expensive hydraulic fracturing operations are common for enhancing well productivity in low-permeability reservoirs. Part of the expenses of these operations incur owing to using low-damaging fracturing fluids, while the true significance of the formation damage in fractured wells is still not clear. This paper evaluates the significance of fracture face matrix damage in multi-fractured horizontal wells.
We analyzed the effect of facture face skin on productivity of multi-fractured horizontal wells using a recently developed mathematical model. This model was derived on the basis of a rigorous coupling of reservoir pseudo-radial flow, reservoir linear-flow, fracture linear-flow, and fracture radial-flow near the wellbore. Results were sensitized to reservoir properties and facture face matrix skin properties determined by fracturing fluid properties and treatment conditions. Large ranges of possible leak-off coefficient and spurt-loss coefficient were investigated. Both oil and gas reservoirs were considered. We concluded that fracture face skin has a little influence on productivity of multi-fractured horizontal wells. Even in the worst situations, the reduction in well productivity due to fracture face matrix damage is less than 5%. Therefore, it is not necessary to use expensive low-damaging fracturing fluids in most hydraulic fracturing operations.