The Effects of Perforation Erosion on Practical Hydraulic-Fracturing Applications

Predicting perforation erosion and its effects on fracture dimensions, fluid distribution, and pressure drop can be an essential part of successful design of hydraulic-fracturing treatments, especially for massive treatments along the horizontal wells when limitedentry techniques are implemented. Both the perforation diameter D and discharge coefficient C-d increase dynamically as proppantladen slurries are pumped through perforations, making it necessary to consider the changes of these two variables in terms of time to predict the perforation-erosion effects. In this paper, we conduct a study of the perforation-erosion effects by implementing our new perforation-erosion model derived from experimentally verified abrasion mechanisms to calculate the rate changes of these two variables and the consequent influence on the fracture dimensions, fluid distribution, and downhole pressure during a treatment. The selected parameters affecting the erosion effects in the study include perforation number, perforation-cluster spacing, in-situ stress difference, and fracturing-fluid viscosity. The results demonstrate that our model can predict the perforation-erosion effects on practical hydraulic-fracturing applications in a physically clear and mathematically concise manner under different circumstances by inspecting the simultaneous increases of D and C-d separately, leading to more-appropriate treatment designs, especially with the limited-entry techniques.