Mechanisms and Influencing Factors of Multi-Directional Acid Etching Communication

ABSTRACT: The Ordovician carbonate reservoir in the Tahe Oilfield exhibits significant heterogeneity in reservoir space due to multiple phases of geological evolution and tectonic activity, resulting in a complex distribution of fractures and cavities with varying shapes and sizes. As reservoir development progresses, the focus has shifted from the large, well-connected fracture-cavity systems near the wells to smaller, more isolated fracture-cavity networks. This transition necessitates the development of an optimized technical framework to enhance connectivity and improve productivity within these smaller fracture-cavity systems, particularly in the weathered crust karst zone. To address these challenges, this study employs a data coupling simulation approach integrating Petrel and AiFrac-COMSOL to systematically investigate the effects of acid injection rate, acid-rock reaction rate, reservoir temperature, and permeability on multi-directional acid etching. The findings provide critical insights into optimizing acid fracturing strategies in highly heterogeneous carbonate reservoirs, contributing to more effective stimulation treatments and enhanced hydrocarbon recovery.