Status and advance of seismic diffraction exploration in coalfield

In China, there is an urgent need for intelligent and environmentally friendly coal mining practices to address the issue of accurately mapping transparent geological conditions, including coal rock structures, water-bearing bodies, goafs, and underground stress. These hidden disaster-causing bodies are prone to triggering mine accidents such as water inrush or gas outburst, which is the main obstacle to safe and intelligent coal mining. Three-dimensional seismic exploration is the main technology for detecting geological bodies such as faults and collapse columns. However, this technology, based on the framework of reflection theory, faces challenges in detecting small-drop faults and small-scale collapse columns. To develop a fine exploration theory and method for hidden disaster-causing bodies in coal fields is a basic research issue for safe and intelligent mining. The seismic exploration framework based on diffraction theory can theoretically break through the bottleneck of traditional seismic exploration resolution and this cutting-edge technology has been continuously reported in authoritative exploration journals. Domestic and foreign industries and research institutions have also invested a lot of research work, but have not yet formed a systematic method and mature software. To solve the problems of coalfield disaster source prevention and intelligent mining, a seismic exploration system based on the diffraction theory framework is proposed. This system includes weak signal acquisition involved with the propagation law of different types of diffractions, extraction of high-resolution diffraction information by multi-domain difference features of reflected and diffraction waves, a fine diffraction velocity modeling method based on a scattering point model, diffraction interpretation of multi-attribute fusion and the corresponding impedance inversion technology. The proposed seismic diffraction exploration has the potential to provide a basic discipline and frontier technology suitable for the safe mining of transparent mines in China.