Depth Map Artefact Recognition and Correction below a Complex Overburden for GIIP Re-Evaluation Offshore the Netherlands

In 2014 a GIIP redetermination across an equity boundary was undertaken in block N07-FA located within the Ameland gas field, offshore The Netherlands. The project required an accurate structural container to avoid bias in the GIIP allocation across the equity boundary. The original PSDM data in depth exhibited significant artefacts at top reservoir related to pull-up induced by stringers located within the overlying Zechstein section. Attempts to correct these artefacts using conventional time-depth modelling techniques failed to provide an acceptable result. A novel approach was tested and used to generate an artefact free and geologically acceptable top reservoir structure map in depth which was subsequently used as input into the static geological model build. The paper explains the origin of the pull-up, demonstrates how artefacts were identified and how the pull-up was corrected to the satisfaction of all stakeholders.