Well Top Review Study
We have been approached by a client with the task to review the well tops from four adjacent fields in the Caspian Sea. Our client had recently acquired new seismic data and wanted to reassure the well tops to do a correct time-to-depth conversion of the seismic. This task comprised more than 350 wells of different ages with different open hole log data available for the analysis.
Another goal of the study was to check whether the pick strategy has been consistent within all involved personnel over the years and to correct any deviations. For client’s internal training and quality assuarance we created a catalog of typical log behaviour for each well top.
NiMBUC completed the whole study within four months.
Project workflow
- QC of data received from client.
- Setup of new database with all log and well top data from >350 wells and seismic.
- Review of existing well tops and re-picking of deviating tops. Adding missing well tops to database.
- Presentation of work and discussion with client. Reporting and creation of deliverables.
The project was done using SLB’s Petrel®, so that the database could be easily imported into the client’s systems.
Also the existing seismic data were taken into account to consider structural and sedimentological changes between the wells. This allowed the direct comparison of the picked well tops to make sure that always the same log patterns we chosen for well top picking and that depth changes due to faulting or more or less basinward well position were compensated.
Furthermore literature and independent data on the depositional and structural history of the Caspian Basin were studied to visualize the geological history of the region.
