Study of mechano-chemical effects on the morphology of hydraulic fractures

Abstract

Acid fracturing is one of the main stimulation technologies in carbonate reservoir. Understanding the mechano-chemical effects on the morphology of hydraulic fractures is of great significance for acid concentration optimization. Based on the true tri-axial experiments on carbonate and CT scan and 3D reconstruction technology, the experimental results indicate that the hydraulic fracture changes from horizontal fracture to vertical fracture. In the process of acid fracturing, the stress field plays a dominant role in the formation of hydraulic fractures when the acid concentration is less than 10%, while the chemical reaction plays the dominant role when the acid concentration is more than 20%. The natural fracture system developed in carbonate reservoir provides seepage channel for acidizing reaction. With the increasing development of natural fractures, the hydraulic fractures formed in the process of acid fracturing are more complex, and the influence of acidizing reaction on acid fracturing is more serious. • The true tri-axial acid fracturing experiments are conducted. • The effect of mechanochemical synergism on acid fracturing are analyzed. • The effect of natural fractures on acid fracturing are analyzed.