| 摘要 |
A method of offshore seismic surveying for obtaining data in areas with gassy unconsolidated sedimentation is disclosed. A shallow, or high resolution, seismic survey is performed to map acoustic properties of the water bottom and distinguish between slab areas of the gassy sedimentation, which have relatively good acoustic impedance matching with water bottoms, and scar areas of the gassy sedimentation, characterized by poor impedance matching, giving rise to water bottom multiples. After the slab and scar areas are mapped, conventional seismic profiles may be obtained in the slab zones. For surveying the scar zones, a source vessel is located over a slab zone to emit seismic energy waves, while a second vessel, which is moved over the scar zones, senses the response of the submerged formations. Either refraction or reflection shooting may be performed with the source vessel over the slab zone and the second vessel over the scar zone.
|
