Seismic Reprocessing Cost Saving Alternative to New Acquisition An Offshore Northwest Java Sea Example



The Offshore Northwest Java Sea concession, held by Atlantic Richfield Indonesia inc., contains approximately 75;000-kin of seismic data. The vintages of these data range from 1967 to 1986. The streamer lengths for these data vary from 600 m to 2375 m. The trace spacings range from 25 m to 70 m. Typically explorationists working in areas with such a diversity of acquisition parameters will opt for costly reshooting to resolve the differences of these parameters. However, with detailed attention to pre-stack analysis, trace interpolation and proper stacking parameters, these diverse data sets can be rendered useful. Approximately 1600 km of data of varying vintages were reprocessed in the Offshore Northwest Java Sea concession held by Atlantic Richfield Indonesia Inc., with the purpose of defining stratigraphic objectives. The 1983 data was held as the ‘.’base” survey and all other vintages were phase rotated to match it. The results were very encouraging and, in these times of tight exploration budget, very useful in holding down costs related to new seismic data acquisition. At today’s: prices, seismic data acquisition costs about six hundred dollars per kilometer. The reprocessing of these data costs around one hundred-twenty dollars per kilometer, representing a saving of five to one.


Authors : A. Pranoto, C.V Ponto, Charlie Wu, W.H Stinson & J.D Parker