HR: 08:45h
AN: G41A-04    [PDF]
TI: Monitoring Subsidence Changes over the Lost Hills Diatomite Oil Field, California*
AU: * Fielding, E J
EM: Eric.Fielding@jpl.nasa.gov
AF: Jet Propulsion Lab, Caltech, 4800 Oak Grove Dr., MS 300-233, Pasadena, CA 91109 United States
AU: Brink, J L
EM: JimBrink@chevrontexaco.com
AF: Chevron U.S.A. Production Co., NAU SJVBU Business Unit, 15255 Lost Hills Rd., Lost Hills, CA 93249 United States
AU: Patzek, T W
EM: patzek@patzek.berkeley.edu
AF: Dept Civil and Environmental Engineering, UC Berkeley, 437 Davis Hall, Berkeley, CA 94720 United States
AU: Patzek, T W
EM: patzek@patzek.berkeley.edu
AF: Lawrence Berkeley National Lab, University of California, 1 Cyclotron Road, MS 90-1116, Berkeley, CA 94720 United States
AU: Silin, D B
EM: DSilin@lbl.gov
AF: Lawrence Berkeley National Lab, University of California, 1 Cyclotron Road, MS 90-1116, Berkeley, CA 94720 United States
AU: Blom, R G
EM: Ronald.Blom@jpl.nasa.gov
AF: Jet Propulsion Lab, Caltech, 4800 Oak Grove Dr., MS 300-233, Pasadena, CA 91109 United States
AB: SAR, GPS and LiDAR monitoring of the Lost Hills giant oil field in central California shows dramatic changes of subsidence over the last 15 years. Subsidence is caused by fluid withdrawal and subsequent compaction of the diatomite petroleum reservoir and in some areas has reached cumulative subsidence of 2 meters since 1989. Measurements of the surface elevation changes with semi-annual GPS surveys and SAR interferometry (using ERS-1 and ERS-2 satellite data) show subsidence rates exceeded 1 mm/day during 1995-1996 in the central part of the oil field. By 1999-2000, increased injection of water to replace the extracted fluids meant that no part of the Lost Hills field was subsiding faster than 0.5 mm/day and some areas that had extremely rapid subsidence before were slower than 0.2 mm/day. We increased the temporal resolution of the subsidence measurements for late 2002 and early 2003 by analyzing more frequent SAR acquisitions from the Radarsat-1 satellite to better understand the compaction response to changes in the oil field operations. The Radarsat-1 orbit-repeat period is 24 days but individual interferograms with short time intervals of only 24 days can have substantial errors due to atmospheric variations. Errors can be reduced by making interferograms with longer time intervals or by averaging multiple independent interferograms over a shorter interval. The Radarsat-1 satellite can image Lost Hills from up to six different tracks every 24-day cycle, potentially allowing six independent interferograms. *Part of this work was performed at the Jet Propulsion Lab, Caltech under contract with the National Aeronautics and Space Administration.
DE: 0933 Remote sensing
DE: 1243 Space geodetic surveys
DE: 6344 System operation and management
DE: 6924 Interferometry
DE: 8040 Remote sensing
SC: Geodesy [G]
MN: 2003 Fall Meeting