Abstract: The first-time 3D seismic exploration activities have been made since 1990' B, which were dominated by regional 3D seismic with large bin size, aiming at fnding out large-to medium-sized structural traps and reservoirs, and lots of significant achievements were made. With the advent of new century, the insufficient precision of the first-time 3D seismic activities appeared gradually as the focus of prospecting loward lithologic-stratigraphic reservoirs. So it is necessary to perform the second-time 3D seismic activities in highly evalualed areas covered with 3D seismic survey before. And 5 different technologies are applied such as wide-azimuth geometry and swath coupling, acquisition with nommal or small bin size, seasonal or relatively wet surface acquisition, selection of source parameters by surface condition and application of medium-high frequency geophone and source-geophone array to receive seismic wave. In thick desert area,the main frequency of 45-50 Hz is used, about I5-20 Hz higher than the first-time 3D data, iand signal to noise ratio and fidelity are significantly improved. As a result, the seismic reflection image defnitions of small faults, unconformity surface, pinchout point and sandbody are also improved markedly and the recognition capability of the lithologic traps are intensified in terms of geologic effect.

Key words: Junggar basin, hinterland, lithologic trap, seismic prospecting, large bin size, second-time 3D seismic exploration