Low porosity carbonate reservoirs of the Carboniferous and Devonian periods of the Caspian Basin in Western Kazakhstan are challenging to characterize using traditional well logging methods due to the complex structure of the pore space, which necessitates lengthy and sometimes ineffective production well tests. Limitations of standard well logging methods make it impossible to reliably identify productive reservoirs, determine boundary conditions, and delineate saturation. As a result, a unique approach is required, which includes the integration of special "high-tech" logging tools and wireline formation testers (WFT). This paper effectively demonstrates the use of this approach in an appraisal exploration well.
The use of a wireline formation tester in conjunction with modern complex fluid analyzers and a radial probe allowed for testing several carbonate intervals with extremely low-permeability in one trip, which previously required stimulation to trigger fluid inflow in a cased well. This provided a new perspective on understanding the reservoir structure in the shortest amount of time possible.