Abstract

Based on the analysis and interpretation of drilling and petrophysics documents, the paper evaluates the hydrocarbon potential of the Oligocene sandstone set at field X. The paper presents some methods of gas classification based on gas chromatographic indicators and the hydrocarbon content in the drilling fluid. Besides, the paper also developed a process to analyze the fluid composition in the formation based on the Wh-Bh-Ch indexes on the gas peaks in the mud logging. The interpreted results from 8 gas peaks in the X-S16P well through the Oligocene sedimentary set identified potential oil and gas zones of field X, as well as the distribution of reservoir fluid. By comparing the results of well logging from GR, density, resistivity curves and the analysis of DST, it corrects the O&G behaviors at field X. The DST’s results of X-S16P well at X field in a depth interval of 2,827- 2,887m throughout the interlaced sandstone set indicate an oil flow rate of 8,826 barrels/day, which is coincident with the results of O&G behavior in mud logging; therefore, it’s concluded that the integration of mud logging with other petrophysical documents allows increasing the reliability of O&G potential evaluation. Furthermore, analyzing and evaluating different indicators to determine the gas composition throughout the drilling process is considered a quick way to predict and classify the products.