In order to better circumscribe a petroleum field, several delineation drilling must be carried out to obtain the maximum of the data by using various methods and techniques which will lead to modeling the reservoir to optimize the recovery of its hydrocarbons. Thus, during the drilling of the OKA-01 oil well in the Tshiala (Offshore) field of the DRC coastal basin, the Pinda formation presents an extreme lithological complexity with a combination of siliciclastic carbonate which is associated with a wide variety of environments. We used a method called Gas While Drilling that uses surface-detected gas during drilling for fast determination of valuable reservoir information such as identification and characterization of hydrocarbons in the lower Pinda reservoir, which are the subject and the contribution of this study. The obtained results from this study are represented in graphic form or figures and cross-plots; the latter are analyzed and interpreted according to the different components present in the fluids, that is to say the quantity of the components (C2-C5) to that of the component C1 as well as the rations of Wetness Ratio (Wh); Balance Ratio (Bh) and Character Ratio (Ch). Data collected from our method compared to other methods used during this drilling of the OKA-1 well identified and characterized the heavy oils in the OKA-01 well, indicating a problem of their recovery with primary methods. and secondary; allowing to consider tertiary recovery techniques with a work over project.