Abstract: The Qiongzhusi Formation of Lower Cambrian is widely distributed in the southern Sichuan Basin and is an important shale gas layer for exploration and development. This area has complex geological characteristics both on the surface and underground, facing seismic exploration challenges, such as large terrain undulations, exposed limestone on the surface, high and steep underground structures, multiple coal mine goafs, and low operation efficiency. After more than 10 years of research and practice, key technologies have been developed to solve the difficulties in seismic exploration of the Qiongzhusi Formation in the southern Sichuan Basin: 1) subdivision of the surface element acquisition and observation system, improving the coverage frequency and the aspect ratio of the main target layer, and effectively controlling the acquisition cost; 2) explosion techniques such as optimizing terrain, optimizing lithology, balancing excitation energy, and enhancing explosion coupling; 3) techniques for acquiring and controlling signals that optimize detector selection, detector positions, detector placement implementation, and noise control when receiving; 4) a supporting technology for improving the receiving effects of coal mine goaf through the analysis of lighting models and on-site experiments in coal mining area, which has improved the quality of data acquisition in goaf areas; 5) the promotion and use of node meters that have significantly improved the efficiency of data acquisition. The key acquisition techniques developed for the research have effectively solved the problem of shale gas seismic exploration in complex areas, collecting over 2 000 km² of 3D seismic data in five work areas, providing important technical support for shale gas exploration and development.

Key words: Sichuan Basin, Qiongzhusi Formation, shale gas, seismic exploration, acquisition technology