Vertical seismic profiles require careful data collection and processing because of borehole noise and the necessity of separating upgoing and downgoing waves by apparent velocity. Major problems associated with these VSP data are tube wave noise and insufficient depth sampling.

Optimum processing of these VSP data permits analysis and tracking of the compressional wave field as it propagates at depth. The aliased tube wave noise is effectively attenuated by suitable f-k filtering at some expense of signal bandwidth. Subsequently, upgoing and downgoing waves are separated and enhanced, allowing identification of primary reflections, multiples, and borehole artifacts. VSP processing results show good correlation of nearby CDP data.

Limitations of VSP processing indicate the need for improved data-acquisition techniques. Increasing the source-borehole offset has been shown to attenuate borehole noise, but if interfering low-velocity signals persist, it is necessary to sample finely in depth to insure maximum signal bandwidth and high-frequency resolution after processing.

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