10,323
edits
Changes
Jump to navigation
Jump to search
Line 16:
Line 16: + + Line 22:
Line 24: − − [[file:three-dimensional-seismic-method_fig1.png|left|thumb|{{figure number|1}}(a) A CMP-stacked section. Copyright: a marine 3-D survey. (b) The corresponding 2-D migrated section. (c) The 3-D migrated section. (Data courtesy of Amoco Europe and West Africa, Inc.]]
→Performing 3-D surveys
==Performing 3-D surveys==
==Performing 3-D surveys==
[[file:three-dimensional-seismic-method_fig1.png|thumb|{{figure number|1}}(a) A CMP-stacked section. Copyright: a marine 3-D survey. (b) The corresponding 2-D migrated section. (c) The 3-D migrated section. (Data courtesy of Amoco Europe and West Africa, Inc.]]
A typical marine 3-D survey is carried out by shooting closely spaced parallel lines (line shooting). A typical land or shallow water 3-D survey is done by laying out a number of receiver lines parallel to one another and placing the shot points in the perpendicular direction (swath shooting). Other recording geometries have also been used in acquiring 3-D data. Shooting in circles has been done in the Gulf of Mexico to delineate salt domes. Shooting around a lake or a topographic high to achieve subsurface coverage under the surface obstacle has also been tried.
A typical marine 3-D survey is carried out by shooting closely spaced parallel lines (line shooting). A typical land or shallow water 3-D survey is done by laying out a number of receiver lines parallel to one another and placing the shot points in the perpendicular direction (swath shooting). Other recording geometries have also been used in acquiring 3-D data. Shooting in circles has been done in the Gulf of Mexico to delineate salt domes. Shooting around a lake or a topographic high to achieve subsurface coverage under the surface obstacle has also been tried.
The size of the survey area is dictated by the areal extent of the subsurface target zone and the aperture size required for adequate imaging of that target zone.<ref name=pt07r64>Yilmaz, O., 1987 Seismic Data Processing: Society of Exploration Geophysicists, Tulsa, OK, 525 p</ref> This imaging requirement means that the areal extent of a 3-D survey almost always is larger than the areal extent of the objective. A few hundred thousand to a few hundred million traces normally are collected during a 3-D survey.
The size of the survey area is dictated by the areal extent of the subsurface target zone and the aperture size required for adequate imaging of that target zone.<ref name=pt07r64>Yilmaz, O., 1987 Seismic Data Processing: Society of Exploration Geophysicists, Tulsa, OK, 525 p</ref> This imaging requirement means that the areal extent of a 3-D survey almost always is larger than the areal extent of the objective. A few hundred thousand to a few hundred million traces normally are collected during a 3-D survey.
==Processing of 3-D data==
==Processing of 3-D data==