Exploración geoquímica en el offshore Argentino: sector norte de la Cuenca Argentina

SILIO, OFELIA; BOLATTI, NESTOR; BREA, FABIAN; PALMA, FERMÍN; GOMEZ DACAL, ALEJANDRO; PRINCIPI, SEBASTIÁN

Mendoza

Congreso; 11° Congreso de Exploración y Desarrollo de Hidrocarburos; 2022

Instituto Argentino del Petróleo y del Gas

Surface geochemical analyses is an important tool for the exploration of areas without well data,even in offshore basins. In the Pampa Azul Project framework, Y-TEC and CONICET signed anagreement to study the Argentine Continental Margin with seafloor geochemistry. This paperdescribes the results obtained from the samples taken in the north sector of the offshore ArgentinaBasin during the YTEC-GTGM 4 cruise onboard the R/VAustral in 2019.Thirty-three samples of three different areas were collected: north, central and south. These wereanalysed by organic geochemistry, gas chromatography (free and occluded/adsorbed gas),stable isotopes and energy-dispersive X-Ray fluorescence (ED-XRF) to identify the presence ofseeps and differentiate them from the sedimentary dynamic features.The results obtained show that the highest values of total organic carbon (TOC) are in thenorthern area and are related to the sedimentary accumulation. All the results obtained by organicgeochemistry are poor and do not show anomalies related to seeps.The origin of occluded/adsorbed gases is thermogenic and related to oil, with the best accumulationslocated in the southern area. Based on the stable isotope analysis the maturity of the hydrocarbonsis in the oil window. Furthermore, no secondary and mixing processes have been interpreted in thedeeper samples analysed by stable isotopes.The ED-XRF shows that the high values of redox-sensitive proxies are in the northern area,coincident with the best TOC values. On the other hand, the higher carbonate productivity proxiesare in the southern area coincident with the most mature kerogens.Although a larger number of samples is necessary to make more robust conclusions, it is possible todetermine potential directions of increasing migration distance. In central and southern areas, the distanceincreases from northeast to southwest while in the southern area the distance increases from south to north.In frontier areas without well data, this kind of information is very important to reduce exploratory risks.