--> Abstract: Seismic Amplitude: Its "True" Meaning and Benefit, by A. E. Wren; #90982 (1994).

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Abstract: Seismic Amplitude: Its "True" Meaning and Benefit

A. Easton Wren

In the early days of seismic exploration, signal amplitude had no specific significance, and the recording systems had little or no control on the signal strength or weakness. "Amplitude anomalies" were perceived as spurious and little was done with them in an interpretive sense.

With the advent of the "bright spot" in the early 1970s, it become evident that amplitude held significance with respect to lithology, porosity, and fluid, but the early excitement was replaced with frustration when it become clear that the "bright spot" technology was not infallible in terms of ambiguity, and that many hydrocarbon reservoirs did not exhibit "bright spots." In the early 1980s, the technique of AVO (amplitude versus offset) was seen to be the necessary complimenting technology to the "bright spot" by removing the ambiguity between reservoir sandstone, shale and coal, and shale and porosity in carbonates.

In the interim, geophysicists have recognized many aspects of amplitude and the pitfalls associated with amplitude interpretation.

These include the amplitude filtering effect of geophone array, tuning, side-lobe tuning, multiple interference, and partial gas saturation. All of these, except the latter, may be systematically handled. However, a profound understanding of all aspects of amplitude is necessary before the interpreter can begin to decipher the lithology, porosity, and fluid.

This paper will review the basics, illustrate the problems, and present amplitude success case histories from several producing fields.

AAPG Search and Discovery Article #90982©1994 AAPG International Conference and Exhibition, Kuala Lumpur, Malaysia, August 21-24, 1994