AbstractGas cavities are deposits of gas, which monitoring is a very important problem for the geological surveys. The determination of the number of gas cavities from seismograms is an important problem, which solution is not possible without extra processing of the seismograms. In this work, we numerically solved the problem of exploring the influence of the number of gas cavities on the modelling results. We investigated the possibility of determining the number of gas cavities, specified in the initial problem description of the direct problem, by the results of solving the direct problem of seismic prospecting. In addition, we carried out the comparison of wave fields of the velocity module distribution and seismograms for further revealing the presence of gas cavities.