legacy seismic data Flashcards
Legacy seismic data
What is 4D or Time-lapse seismic?
collection of 3D surveys at different times to monitor changes in reservoir conditions.
Legacy seismic data
What is the possible potential benefit of time-lapse technology ?
significantly increase recovery in new and existing fields.
Legacy seismic data
What are the 3 requirements in order ofr legacy 4D seismic to be used as a tool for reservoir management?
- repeatability of seismic data in non-reservoir portion of the data
- robustness/credibility of seismic differente anomoly within the reservoir
- production history matches seismic differences
Legacy seismic data
List 6 post-stack processes
- regridding
- global equalization and posiioning
- trace amplitude equalization 83 vs 95
- match filtering
- trace alignment and residual migration
- difference display
Legacy seismic data
what are the 2 reasons for the difference in amplitudes between the 2 data sets?
- difference in acquisition
- difference in initial processing
Legacy seismic data
what is the purpose of match filter?
to match characteristics of 2 data sets in terms of shape and frequency content.
Legacy seismic data
what process is applied prior to final differencing?
trace to trace equalization (scaling)
Legacy seismic data
what assumption is made to facilitate processing?
- streamer is straight
- source/cable offsets are fixed
Legacy seismic data
what is a possible consequence of those assumptions?
inc chance of positioning related data misalignment
Specify the 2 QC steps to detect and elminiate positioning related data misalignment ?
QC first break peaks (or 1st arrivals)
QC near offset (NTG - Near Trace Gather)
Legacy seismic data
The reservoir thickness is below seismic resolution. What is the term for this?
Tuning Thickness (where resolution is limited).
