Characterization of the fluid column for the SJN OPR-15 reservoir, Orocual field, Furrial District, Monagas State - Venezuela The Field Orocual is located to the north of Monagas State. In there is the deposit SJN ORP-15, one of major potential in this Field. Due to its energetic decline, for the year 2008 its production was closed by conservation of energy, nevertheless, the well ORP-37 completed during this year, showed a production of 2.0 MBNPD with a RGP lower than 1000 PCN/BN, contradicting the official characterization of the deposit, which was considered as volatile crude oil. Based on the existing PVT analysis in the deposit showing volatile crude oil and that the well ORP-37 showed a black crude oil, the existence of a gravitational segregation associated with variation of composition of the crude oil with depth hypothesis arises. With the aim to corroborate this hypothesis there was performed a characterization study of fluid in the wells ORP-27 and ORP-37. This paper summarizes the evidences that conclude in the existence of the compositional segregation. The work methodology used was: well selection, information capture, bottom samples capture, samples analysis, representativity and consistency comparison of the PVT analysis. The results of this characterization allowed to adjust the equation of the simulation model, improving its representation. In operational terms, the exploitation scheme was re-defined increasing the production towards the flanks, hereby re-defining and ensuring the rational exploitation of the reserves associated to the SJN ORP-15 deposit, by considering its compositional variation.