Acid Penetration in Natural Fracture Networks

Summary In this paper we present a methodology for predicting the propagation of acid along natural fracture networks and the resulting etching of the fracture walls. The natural fracture network is modeled as a system of intersecting fractures that form a main pathway for acid transport and dissolution. The tails of the intersected fractures increase the leakoff from the main pathway and are accounted for in the model. The fracture-network-acidizing model is supported by comparisons with laboratory experiments and smaller-scale simulations that determined the nature of acid channeling at fracture intersections. Model results illustrate the effects variations in fracture properties have on acid propagation. The model predicts deeper acid penetration under matrix conditions than would be possible with matrix flow only.