Analysis of the results determination of the skin factor in conditions of a deficit of initial information

The skin factor is an important indicator characterizing the filtration and reservoir properties of a formation in the near-wellbore zone. The reliable information about its values comes from the interpretation of hydrodynamic studies under non-stationary filtration regimes. However, due to various reasons, this type of research is not always feasible for determining the properties of a porous medium in both wellbore and distant areas of the reservoir. In such situations, indirect methods for assessing the skin factor become particularly relevant.

Objective. To determine the skin factor of producing horizontal wells in conditions of limited high-quality initial information.

Materials and methods. The study used materials from production hydrodynamic studies under stationary and non-stationary filtration regimes and their interpretation results. The methods of mathematical statistics and graphical analysis were applied to process the data.

Results. A correlation was discovered between the skin factor and a complex parameter equal to the pressure drop in the skin zone divided by the flow rate of the well before it stopped for testing. The study provides calculations and their comparison with the actual skin factor levels. The features of the relationship between relative productivity and the magnitude of the skin effect manifestation are discussed.

Conclusion. The presented methodological approach allows for obtaining adequate skin factor estimates, which can be used to solve various oilfield tasks.

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