Underground coal gasification(UCG) is an effective means to exploit deep coal resources, and is a technology of clean and efficient development and utilization of energies. As compared with the traditional coal mining and surface gasification, it enjoys obvious advantages of economy, safety and cleanness, among other advantages. This paper reviews the development history, the gasification principle and the current situation of different gasification processes in the coal underground gasification, and it is pointed out that no-shaft underground coal gasification technology is the development trend in the future. A brief assessment of the latest advances and the development tendency is made, including the site selection, the selective gasifier, the goaf control and detection, the ultra-short horizontal well technology, the classification and the comprehensive utilization of gasification products. It is shown that combined application of the UCG-CCUS technology will make the underground coal gasification truly a new generation of green coal mining technology.

underground coal gasification  /  no-shaft  /  deep resources exploitation  /  UCG-CCUS