Publications

This paper presents the operation design, job execution, and data analysis results of MDT (Modular Dynamic Tester) dual packer survey proposed to define the net pay cut-off in the Abadi field. Although there are still different perceptions concerning net pay cut-off determination, it is becoming increasingly accepted that cut-off must have a dynamic significance and thus cut-off determination should be driven by the available dynamic data rather than by imported static concepts (Worthington et al., 2005). Toward this end, we carried out MDT dual packer surveys to acquire cut-off basis by directly testing lower permeability intervals. MDT dual packer survey provides a fast and flexible way of testing multiple zones of interest, while avoiding an expensive well testing operation (Schlumberger, Modular Formation Dynamic Tester Module, 2013). The tool configuration and operation procedures were carefully designed at the preparation stage to avoid tool sticking issue and acquire high quality data from low permeability intervals for the subsequent analysis. The results from wireline log including XPT survey (single probe pressure measurement) was effectively utilized to select the target station points from the cored intervals. At all the station points, MDT jobs were successfully executed based on the design, confirming the gas flow by LFA (Live Fluid Analyzer) and sampling. The average permeability in the tested intervals was estimated in a range from 0.002 mD to 0.067 mD from pressure transient analysis. Core measurement results suggested the petrophysical cut-off values could be defined as 0.04 mD for permeability.