Both results (Figures and ) present a hyperbolic moveout at near offset or small offset-to-depth ratio. This result resembles the well known theoretical presentation of Tessmer and Behle (1988). However, the non-hyperbolic moveout is dominant for large offsets and shallow depths, as can be observed in Figure .

mod5
Reflectivity model.
Figure 1 |

mod5NMO
Modeled data, using the non-hyperbolic equation with
a constant value of .Figure 2 |

mod5NMO1
Modeled data, using the the traditional hyperbolic equation.
Figure 3 |

I also apply the non-hyperbolic moveout equation to a PS CMP gather from the Alba dataset acquired on the Alba oil field in the North sea. The data set is a multicomponent 3-D Ocean Bottom Seismic experiment. Figure shows the original CMP gather before (left), after (center) non-hyperbolic moveout, and after traditional hyperbolic moveout (right). I use an initial velocity value of 1100 m/s, and a velocity gradient of 125 and a constant . Note that even though the events are not totally corrected, the non-hyperbolic correction gives a better result for shallow events at large offsets. These events are flatter after the non-hyperbolic moveout correction than with the hyperbolic moveout correction.

Figure 4

10/23/2004