Seismic Detection Of Viscous Contaminent Using Shallow Seismic Reflection

We conducted a high resolution very shallow seismic experiment in order to image<br>the effect of viscous fluids on signal attenuation in surface acquired seismic data. We<br>mixed 20 liters of honey with 200 liters of beach sand. Then we buried the mixture in a<br>pit at depth of 1 m in the center of the seismic line. We collected two CDP seismic<br>. sections, the first one with a dry pit, and the second with the honey sand mixture in the<br>pit, and analyzed the effect of the pore fluid on reflection strength. The spatial location of<br>the honey could be determined by the attenuated water table reflection, precisely in the<br>place where the honey was buried. The attenuation was higher in the 700Hz CDP stacked<br>section than in the 350Hz CDP stacked section. In this paper we discuss three aspects of<br>the problem: 1) Simplified assumption for attenuation mechanism and a methodology to<br>estimate the location of viscous pore fluid and its viscosity. 2) The experimental<br>description and 3) Seismic data processing issues, with application to fluid monitoring.<br>We show that given sufficient bandwidth, viscous contamination can be imaged from the<br>surface.