Seismic Absorption and Modulus Measurement in Porous Rocks Under Fluid and Gas Flow-Physical and Chemical Effects: A Laboratory Study

摘要

This paper describes the culmination of a research project in which we investigated the complex modulus change in partially fluid saturated porous rocks. The investigation started with simple flow experiments over 'clean' and 'contaminated' surfaces, progressed to moduli measurements on partially filled single cracks, to measurements in 'clean' and 'contaminated' porous rocks and finally to a feasibility study in the field. For the experiments with the simple geometries we were able to measure fundamental physical properties such as contact angles of the meniscus and time dependent forces required to get the meniscus moving and to keep it moving at various velocities. From the data thus gathered we were able to interpret the complex elastic moduli data we measured in the partially saturated single cracks. While the geometry in real rocks is too complex to make precise calculations we determined that we had indeed identified the mechanisms responsible for the changes in the moduli we had measured.