Using Wireline Formation Tester Pressure Survey to Validate and Fine-tune Model Building: A Case Study for a Multi-layered Mature Reservoir

Abstract

Wireline Formation Tester surveys are routinely performed for pressure profiling in all new wells. These surveys are being extensively used to identify contacts, cross communication etc. The information is updated and integrated for a full field perspective so that depletion trends, communication across faults, and presence of sub-layers within the main sand lobes are identified, validated and mapped. This data set is acquired over time, against a well laid out strategy and against all the sands.As a precursor for building a model in a multilayered mature oil field of Kuwait, the collected data were analyzed to draw interesting and operationally important conclusions.The study reinforced the sub-layering classification followed in the field on a broader scale; however in a few instances, marked anomalies were noted. The existing sand layering scheme was revisited and corrections applied by adjusting the layer tops in those wells.Multiple pressure points across adjacent sub-layers with close pressure regime were grouped and re-grouped and plots were generated. The layers followed the existing geological layering scheme; but in some instances, the plots indicated a different picture of the extent of these sub-layers. This type of validation of layering scheme of the static model gave important insights during upscaling for the dynamic model. Analyses of the plots were carried out in different segments for well clusters across faults. The plots uncovered important information about the nature of the faults. Conclusions drawn from these plots are planned to be used for supplementing Pressure Transient Analysis information during history match.