Geophysical Society of Houston, Texas (GSH), Technical Luncheon

Location: PGS office, 15375 Memorial Drive, Houston, TX 77079 
13 September, 2023  |  Meeting time: 11:30 am – 1:00 pm 

Benefits of focused post-migration gather conditioning over prospect specific areas – an Indonesian case study.


Harbour Energy had identified a number of amplitude supported exploration prospects, however, observed differences in event alignment, noise level and bandwidth between contractor processed angle stacks gave rise to concerns about the prestack amplitude fidelity of the data and its suitability for quantitatively evaluating the prospects.

Sharp Reflections was brought in to perform full-volume prestack gather QC, post-migration gather conditioning and AVA attribute generation. The objective was to provide reservoir-focused, quality assured prestack gathers and derivative attributes to assist in prospect evaluation and exploration drilling planning. The Sharp Reflections team used iterative full-volume QC attributes at each step of the conditioning process to assist with algorithm parameterization and to address spatial and temporal variations in data quality.

Quality assurance of pre-stack seismic data is a critical step in any AVA analysis or Quantitative Interpretation workflow. Full-volume pre-stack data QCs take quality assurance beyond the traditional “test-line” approach and help to avoid aliasing the worst data problems in a given study area. The reservoir-focused approach to gather conditioning resulted in what appeared to be minor changes in computed pre-stack attributes in comparison to standard production processing, but demonstrated the potential to provide significant additional insights into the subsurface picture.

The workflow resulted in improved amplitude fidelity across the angle stacks, specifically in terms of S:N, bandwidth consistency and event alignment, with Class IIp events clearly preserved and enhanced. Resulting AVA attributes and EEI volumes demonstrated enhanced resolution of the prestack signal and allowed Harbour Energy to confidently calibrate the observed responses against pre-drill scenarios. The play-opening discovery well was drilled by Harbour Energy in Q2 2022, providing valuable calibration for prestack inversion work to follow.

Kathryn Young, MS in Geophysics from the University of Texas at Austin, began her career with EOG Resources in South Texas, where she contributed to the full evolution of the Eagle Ford play. She subsequently spent a decade in BP’s central upstream technology team, supporting asset teams globally across diverse geological environments.

Kathryn joined Sharp Reflections in 2022 as Business Development Manager for Americas . With her extensive experience in technical services, she excels at listening to clients, identifying key challenges and proposing practical deliverables that drive business value.