Comprehensive Reservoir Vertical Interference Testing to Optimize Horizontal Well Placement Strategy in a Giant Carbonate Field

摘要

This article discusses the early evaluation of vertical connectivity with vertical interference tests (VITs) using an advanced multi-probe wireline formation tester (WFT) in a giant carbonate field in Saudi Arabia. The objective was to determine the vertical permeability of low permeability layers within the reservoir. Early understanding of such vertical connectivity is required to ensure the optimum development of new fields with limited dynamic data. To conduct the evaluation, an advanced multi-probe WFT was utilized in five key wells around the field to obtain vertical and horizontal permeabilities. Several VITs created pressure pulses at the dual-packer, which produced pressure responses monitored at two observation probes in real time. The vertical connectivity was assessed from the pressure responses to the transient generated across the stratigraphic layers. Comprehensive interference tests were conducted across all the layers. Advanced nonlinear regression analysis techniques were utilized for pressure transient analysis at test intervals. The results were further confirmed with a fine gridded 3D reservoir simulator. The integration of all vertical permeability results obtained so far indicate a good degree of reservoir vertical connectivity. The VIT results were used as input in the field simulation model, improving the accuracy of the vertical permeability determination in different areas of the reservoir, which in turn supported changes in the well placement strategy for maximized recovery.