Abstract The research was carried out to estimate the free oil, obtaining an approximation of the recoverable oil and the determination of the additional recovery factor. This methodology can estimate the residual oil saturation, through the partitioning of the porous medium classified into three types (interparticle, vugs and fractures), it's made from the elastic parameters, obtaining velocity-porosity models which in turn they are related to sedimentary facies features. The estimation of free oil is very useful in the valuation of reserves, making the geological and petrophysical considerations typical of a static characterization of the reservoir and the dynamic considerations of the reservoir influenced by the extraction conditions of the hydrocarbons. The recovery of hydrocarbons from a triple porosity carbonate reservoir, such as the present case study in the Cantarell field, it is generally estimated using factors that depend on the degree of knowledge of the reservoir; previously approximations are obtained by correlation with analogous fields, as the reservoir is exploited, this recovery factor is required with the support of the extraction-operation conditions and the collection of information that is acquired through the development wells and injection wells. according to the case. In reservoirs of this nature, volume data, reserves and recovery factors are updated, as information is added, knowledge increases, technologies are incorporated and, eventually, commercial circumstances influence. The determination of the additional recovery factor was 4.6%, it is a significant aspect, in this case study the petrophysical aspect is addressed considering investigations applied by other authors Salazar, (1993), Fernando Samaniego, (2015) and specific studies of wells in naturally fractured reservoirs of the Campeche Sound (México), where estimates an increase-profit range of recoverable oil.