Problems of the completeness of oil recovery from the reservoirs in Russia are becoming increasingly relevant. They are largely caused by the complexity of the geological structure of the layers (reservoirs). Filtration heterogeneity of various types during the development of oil field leads to the formation of stagnant or bypassed oil zones, which are practically not produced. In modern development practice, the spatial distribution of oil-saturated areas in developed fields using special studies is far from always determined. Usually, only mathematical simulation is used for solving this problem.
This work is aimed to explore the possibility of identifying the undeveloped oil reserves (bypassed by waterflood) based on wells tests analysis and mathematical simulation, accumulating the results of other types of studies. Two hypothetical models of the part of the oil reservoir were created, differing in geological structure properties - a homogeneous reservoir and a heterogeneous reservoir with zones of the reduced permeability (in which the bypassed zones of the residual oil are then formed during the development). Using these models, the bottom hole pressure changes were calculated for various types of wells tests analysis: the method of pressure buildup and Interference test. The resulting curves were interpreted using the best fit method. The considered integrated approach using mathematical simulation and well test analysis allowed us to confirm the presence of a zone with reduced permeability (assumed by the results of the development analysis) between the studied wells.
Based on the study of a hypothetical field, diagnostic features are formulated to identify the bypassed areas saturated with oil using mathematical modeling and well test analysis. They allow to verify the filtration model and to recommend drilling infill wells or sidetracks to recover the remaining oil reserves.
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