Rapid acquisition of high resolution full wave-field borehole seismic data.

摘要

An essential requirement for both Vertical Seismic Profiling (VSP) and Cross-Hole Seismic Profiling (CHSP) is the rapid acquisition of high resolution borehole seismic data. Additionally, full wave-field recording using three-component receivers enables the use of both transmitted and reflected elastic wave events in the resulting seismic images of the subsurface. To this end, an advanced three- component multi-station borehole seismic receiver system has been designed and developed by Sandia National Laboratory (SNL) and OYO Geospace. The system requires data from multiple three-component wall-locking accelerometer packages and telemeters digital data to the surface in real-time. Due to the multiplicity of measurement stations and the real-time data link, acquisition time for the borehole seismic survey is significantly reduced. The system was tested at the Chevron La Habra Test Site using Chevron's clamped axial borehole vibrator as the seismic source. Several source and receiver fans were acquired using a four-station version of the advanced system. For comparison purposes, an equivalent data set was acquired using a standard analog wall-locking geophone receiver. The test data indicate several enhancements provided by the multi-station receiver relative to the standard, drastically improved signal-to-noise ratio, increased signal bandwidth, the detection of multiple reflectors, and a true 4:1 reduction in survey time.