The Role of Back Pressure and Perforation Hole Erosion on the Magnitudeof the Coefficient of Discharge in Hydraulic Fracturing Stimulation

摘要

Hydraulic fracturing or fracking is a well stimulation technique for extracting hydrocarbons from naturallylow (extra low) permeable oil and gas reservoirs. In this process water, proppant and chemicals are injectedthrough the wellbore and from the perforation hole into the reservoir. The main goal of this treatment is tocreate artificial fluid path conduits in the formation and finally increase the permeability (and productivity)of the reservoirs. One of the important factors which affects the near wellbore fluid pressure drop is the coefficient ofdischarge (Cd) which is a characteristic of the perforated hole in the wellbore tubular. The coefficient ofdischarge is defined as the ratio of the measured mass flow to the theoretical mass flow. The Cd dependson many factors and may change with time due to erosion caused by the injected sand, which was pumpedinto the formation. In this research, we investigated some of the factors that can affect the coefficient ofdischarge like the erosion of the perforated hole and the backpressure given by the fracture.