Geology Research Center, Geophysical Research Institute, Bureau of Oil Geophysical Prospecting, P.O. Box 11-1, Zhuozhou City, Hebei Province, 072751, China
Abstract:The image of crosshole seismic reflection wave has higher resolution than the tomographic image of crosshole seismic velocity does; and the section of crosshole seismic reflection wave may be applied to minute interpretation of crosshole reservoir. The time field of reflection wave of common-shot trace gather(or common-receiver trace gather)is computed by taking ray tracing in nonuniform medium according to real crosshole seismic observation system; and then the image section of crosshole seismic reflection wave can be produced by stacking reflection energies at common-reflection point. This can be achieved in the following steps: Computing the travel times of upgoing and downgoing reflection waves at each reflection point; Separating upgoing wave from downgoing wave according to a given way (common shot,common receiver, common offset, common mid point or common depth point); The upgoing wave and downgoing wave undergo CRP stacking respectively, then they are merged into a single section; Both theoretical model and real data processing bring good crosshole seismic sections.