Obtaining an image of an underground formation

摘要

A method for creating an image of an underground formation around a borehole. An omnidirectional seismic source is activated in the borehole and a three-component receiver records the components of the reflected energy from the formation. The direction or ray of the returned energy is computed as a function of the two-way travel time A position in the formation is selected as a potential formation reflection point compared with the directional ray and two-way travel time. Where the directional ray and two-way travel time substantially correspond to the selected point, the data is attributed to the selected point The process continues with the selection of additional points and calculation of attributed return energy direction and two-way travel time to such points to comprise a set of reflectors which form the image of the formation.