Application and Progress of Acidization Technology in Geothermal Development: A Review

As a sustainable alternative to fossil fuels, geothermal energy plays a critical role in the global shift toward carbon neutrality. However, the economic extraction of heat is frequently hindered by poor-reservoir permeability, often exacerbated by mineral scaling and particulate clogging during long-term operation. This review provides a comprehensive synthesis of acidization technologies, emphasizing their mechanisms for enhancing injectivity and productivity in diverse geothermal settings. This study scrutinizes the chemical interaction between varied acid systems ranging from conventional mineral acids to solid organic acid blends and the complex geological conditions of volcanic and sedimentary reservoirs. Furthermore, the paper delineates the evolution of geothermal energy development methods, such as matrix acidizing and hydraulic fracturing synergy (multi-stage acid fracturing), alongside metal corrosion inhibition and effluent scale treatment. By integrating empirical field data with theoretical geochemical modeling, this review provides an in-depth analysis of the acid fracturing mechanisms within coupled thermal–hydraulic–mechanical–chemical (THMC) fields. It further identifies the persistent challenges of high-temperature stability and deep-seated flow path diversion. Ultimately, this paper proposes a roadmap for next-generation “smart” acidizing fluids, aiming to provide a robust framework for optimizing geothermal heat mining and ensuring the longevity of enhanced geothermal systems.