Active seismic characterization experiments of the Hontomín research facility for geological storage of CO2, Spain

Abstract

An active source seismic experiment was carried out as part of the subsurface characterization study of the first Spanish Underground Research Facility for Geological Storage of CO2 in Hontomín (Burgos, Spain). The characterization experiment included a 36km2 3D seismic reflection survey and two three-component seismic profiles. The target reservoir is a saline aquifer located at 1450m depth within Lower Jurassic carbonates (Lias). The main seal is formed by interlayered marlstones and marly limestones of Early to Middle Jurassic age (Dogger and Lias). The seismic images obtained allow defining the 3D underground architecture of the reservoir site. The structure consists of an asymmetric dome crosscut by a relatively complex fault system. The detailed characterization of the fracture system is currently under study to unravel the geometric distribution of the faults and their extent within the different formations that form the structure. The constrained model has guided the design of the injection and monitoring boreholes and provided the data for the baseline study. The resultant high resolution seismic model will be used as a reference in future monitoring stages.