The validation of initial data is an important process to reduce the risk of errors in calculations. The large amount of heterogeneous data in the area of hydrocarbon reservoirs development leads to a significant increasing in complexity and calculation time of data validation. Here, we consider the problem of validation and completion of the initial data for the task of hydrocarbon reservoirs development. A validation and completion method, based on the use of 3D visual models and searching of analogies, is proposed. The results of testing the proposed method on the data of reservoirs of the Tomsk region of the Russian Federation are shown. The results showed that the time of the procedure of validation and completion of the initial data was reduced by 22.2% for projects of reserve calculation and by 32.2% for projects of development forecast in comparison with standard manual validation procedure. During the validation, experts identified 18% and 13.5% more errors with the proposed method for projects of reserve calculation and development forecast, respectively, showing that the proposed method could be an effective tool for data validation and completion. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.