Prediction of the Cross Section Below the Td by Means of the Versions of the VSP Method

The possibility of prediction of the geologic section below the TD distinguishes the method of vertical seismic profiling (VSP) from all other methods of geophysical researches of wells. In the VSP method the incident waves and waves reflected from the seismic boundaries, located under the bottom, are recorded simultaneously. Thus, in contrast to surface seismic exploration, a more correct solution of the inverse kinematic and dynamic problems, aimed for the study of the section below the bottom, is provided. Several versions of the VSP method are currently used, each of which has a number of advantages and disadvantages. The combination of different versions allows one to study the elastic properties of the subsurface and the section under the bottom of the well by using of kinematic and dynamic parameters of waves of different types and classes. In the report the standard versions of the VSP, such as zero-offset and offset VSP as well as non-standard version –moving source VSP having a number of obvious advantages over the offset VSP at the forecast of the section under the bottom of borehole, - are considered. Experimental and model results for solving geological and engineering problems are shown for various versions of the VSP method.