Paper deals with actual problem about making decisions while development of the field. The main aim was to apply method "Value of information" in order to estimate the necessity of exploration works for the field and show the effectiveness of this method. The object of analysis - field X, which is located in the Eastern Siberia. The reservoir is B13 formation of Vend age. Field has complex structure, and divided into blocks by faults. During evaluation of the project, main uncertainties and oil in place were obtained for three blocks of the field. According to uncertainty analysis, it was suggested to drill new exploration well, and value of information method was applied to estimate results from this exploration works. Economic evaluation the value of information was made on the base of choosing optimal development strategy. According to the obtained results, drilling of the exploration wells for blocks 1 and 3 of the field X is a good decision, while drilling of a well in the second block is risky and not recommended. Also using the value of information, optimal well locations were advised - well 1-1e for the first block, and well 3-3 for the third block.