| Borehole seismic data has become significant, important and useful in recent years when its depth dimension has been introduced to the oil exploration and production world. In this dissertation, a general imaging and processing system is developed and applied to two types of borehole seismic data: vertical seismic profile (VSP) and cross-well transmission (CWT) data.; A pre-stack imaging algorithm for 2-D variable velocity media based on the excitation time imaging condition is developed. It requires two distinct extrapolations: source extrapolation, and recorder extrapolation. Three methods are developed with the same imaging principle using ray tracing and finite differences as extrapolators. Total recorded data wavefields can be used as input; the contribution to an image, of the transmitted energy, can be separated from the scattered energy by 2-D high pass wavenumber filtering after imaging.; The imaging resolution can be improved by increasing the recorder and source apertures to preserve a wide range of wavenumber components in the data that are then available for inclusion in imaging. Signal-to-noise ratio is improved by stacking images from more sources through constructive interference at diffractor locations and destructive interference elsewhere.; A generalized transformation and processing system is developed for data processing. Data transformation is performed by the Radon transform (slant stack), the Fourier transform, and resampling using the Fourier central slice theorem. Each transform performs a reversable operation; thus, the system is flexible to use. Viewing the original data in a variety of spaces allows optimal filters to be designed and applied. A 2-D window filter allows various processing tasks to be performed, and completes the system.; Test data are computed by finite difference modeling to verify and to evaluate the processing algorithms. Real VSP and scale-model CWT data are processed to illustrate a variety of practical applications. |
