Plane wave source imaging, controlled Illumination and AVA gathers
面炮成像、控制照明与AVA道集

Prestack depth migration based on wavefield continuation is the most reliable method for complex structure imaging in subsurface,whereas,it needs large computation costs and has poor adaptive geometry.Plane wave source migration is another way of wave equation-based accurate prestack imaging with high efficiency and without migration aperture problem.Moreover,wavefield energy can be compensated at the target zone by controlled illumination.In this paper,prestack depth migration accomplished by the control of downgoing wavefield of plane wave and selection of the number and range for the rays,in order to gain the best result of imaging.Moreover,the controlled illumination techniques are applied to enhancing the precision of interesting area.Simultaneously,the amplitude versus incident angle(AVA) gathers can be acquired on the benefit of amplitude interpretation and reservoir lithologic prediction.Numerical calculation indicates that plane wave source imaging is a rapid and efficient method with less computation cost and easy parallel algorithm,in similarity of precision with single square-root operator imaging for common shot gathers and double square-root operator imaging for common middle point gathers.