Abstract

More information about formation properties than is commonly utilized is available in the acoustic signal. The objective of full-wave acoustic logging is to use more of this information to determine formation properties. properties. Full-wave acoustic tools generally have transmitter-to-receiver spacings greater than about eight feet. This provides deeper penetration and facilitates signal analysis. Full-wave acoustic signals are briefly discussed.

Shear wave slowness, or is one of the most important new acoustic logging measurements. Used with, provides basic log quantities for lithology identification, gas zone identification, estimation of lithology and porosity with acoustic logs only, and improved formation elastic property estimation. property estimation

Introduction

More information about formation properties than is commonly utilized is available in the acoustic signal propagated down a borehole. In fact, present logs, the most common open hole acoustic logs, represent only a present logs, the most common open hole acoustic logs, represent only a small fraction of the potential information in the acoustic signal. The objective of full-wave acoustic logging is to use more of the information to determine formation properties. Such properties include , , / , lithology, rock elastic moduli, compressional and shear attenuation and reflection coefficients.

Shear wave slowness, or, is one of the most important of the new logging measurements provided by the analysis of full-wave acoustic signals. The main objective of this paper is to present several examples of the use of shear and compressional wave slowness logs. Characteristics of full-wave acoustic signals are briefly discussed for background.

FULL-WAVE ACOUSTIC SIGNALS

The full-wove acoustic signal is composed of four main types of waves: compressional, shear, pseudo-Rayleigh and Stoneley. Compressional and shear waves are often referred to as P and S waves respectively.

p. 6-37 p. 6-37

This content is only available via PDF.
You can access this article if you purchase or spend a download.