HR: 15:15h
AN: U33A-06    [Abstracts]
TI: Interpretation And Mathematical Modelling Of Temporal Changes Of Temperature Observed In Borehole Yaxcopoil-1 Within The Chicxulub Ipact Structure, Mexico
AU: Safanda, J
EM: jsa@ig.cas.cz
AF: Geophysical Institute, Czech Academy of Sciences, Prague, Prague, Czech Republic
AU: Wilhelm, H
EM: helmu.wilhelm@gpi.uni-karlsruhe.de
AF: Geophysical Institute, University of Karlsruhe, Karlsruhe, Karlsruhe, Germany
AU: * Heidinger, P
EM: heidinger@gmx.net
AF: Geophysical Institute, University of Karlsruhe, Karlsruhe, Karlsruhe, Germany
AU: Cermak, V
EM:
AF: Geophysical Institute, Czech Academy of Sciences, Prague, Prague, Czech Republic
AB: The geothermal research of the Chicxulub impact structure on the Yucatan Peninsula, Mexico, included repeated temperature logs of the 1.5 km deep borehole Yaxcopoil-1, which were done following 0.3-0.8, 15, 24, 34 and 50 months after shut-in of drilling operations. A gradual distortion of the linear temperature profile by a cold wave of the 0.8 -1.6°C amplitude was detected propagating downward from 145 m to 317 m within the observational period of 50 months (March 2002 - April 2006). As an explanation of this unusual phenomenon, the hypothesis of a downward migration of the drilling mud, accumulated within the overlying and cooler highly porous and permeable karstic rocks during the drilling, was proposed. Velocity of the downward propagation of the cold wave decreased appreciably between the last two logs (December 2004 - April 2006). It may indicate that the mud migrating downward through the system of interconnected caverns and conduits reached a bottom of the secondary porosity zone. We present results of simulations of thermal effects of the downward migrating drilling mud, obtained by a numerical solution of the heat transfer equation in a set of geothermal models of the borehole and its surroundings.
DE: 1828 Groundwater hydraulics
DE: 1829 Groundwater hydrology
DE: 1834 Human impacts
DE: 1835 Hydrogeophysics
SC: Union [U]
MN: 2007 Joint Assembly