Overview of Blockage Mechanism and Unblocking Technology in Wellbore and Reservoir near Wellbore Zone

During the development of oil and gas fields, the plugging problem in the wellbore and near-wellbore area is a key factor affecting oil recovery efficiency and economic benefits. This paper systematically reviews the research progress on the formation mechanisms, influencing factors, and plugging removal technologies of four common types of plugging, namely wax plugging, scaling, sand plugging, and hydrate plugging. Studies show that plugging is the result of the coupling of multiple physicochemical processes, and is jointly affected by multiple factors such as fluid properties, temperature and pressure conditions, flow rate, and surface properties. Currently, the plugging removal technology has formed a synergistic system of multiple methods including chemical, physical, mechanical, and thermodynamic approaches; however, it still faces challenges such as limited treatment depth, high cost, and risk of secondary damage. In the future, efforts should be made to strengthen research on multi-scale plugging mechanisms and develop environmentally friendly and high efficiency plugging removal agents as well as intelligent monitoring technologies, so as to improve the reliability and economy of complex oil and gas resource development. This paper aims to provide theoretical support and technical directions for researchers and engineers, and promote the innovation and development of efficient oil and gas field development and flow assurance technologies.