Ultrasonic experiments carried out on Rotliegend reservoir sandstone samples have shown a specific stress-dependent behaviour of the transmission response. Apart from the well-known velocity increase as ambient stress increases, the amplitude and the time are scaled when the stress is changed from one value to another. Our hypothesis is that when stress changes, some mineralogical constituents of the rock may change their acoustic properties differently from other constituents. As a consequence, different scattering attenuation effects take place within the rock. The observed stress-dependent scaling behaviour can be a consequence of the latter phenomenon.In order to quantify the scaling behaviour, two approaches are used. First, a heuristically derived model from the experimental data is tested on numerically simulated data. Next, an analytically derived model from a modified version of the O'Doherty-Anstey expression for the transmission response through finely layered media is also analyzed and tested both on numerically simulated and experimental data. Both scaling models present two scalar parameters that relate a wavelet recorded at a high ambient stress with another recorded at a relatively low stress. Estimating these parameters from measurements for a range of different ambient stresses gives valuable information about the stress-dependent behaviour of the reservoir rock.
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