Stratigraphy, Sedimentology, and Reservoir Characteristics of the Lower Member of the Yacimiento El Trébol Formation

摘要

Exploration in the offshore Golfo San Jorge Basin requires anrnunderstanding of the regional trends of the Lower YacimientornEl Trébol Fm. Sandstones. These reservoir rocks yield thernbest oil shows in the offshore and they are among the mostrnprospective and prolific onshore reservoir on the Golfo SanrnJorge Basin’s north flank.rnDetailed correlation enabled identification of three lower orderrnsequences in this stratigraphic interval. These sequences arernrecognizable on seismic sections and well logs.rnThe Lower Yacimiento El Trébol interval was regionallyrncorrelated from the offshore wells to the producing intervals atrnEscalante and El Trébol fields. No major truncations orrnstratigraphic wedges were identified on seismic lines or wellrnlogs, although the individual sequences that comprise thisrnpackage can thin against some persistent structural highs.rnIn addition, these sequences were correlated in 144 wells allrnaround the north flank of the basin; sand thickness wasrnmeasured from the SP curve in these wells. Net sand and sandrnpercent maps were created.rnThese maps demonstrate that lower Yacimiento El Trébolrnsandstones are concentrated in sand fairways in the ComodorornRivadavia area and in the area south of the Marta wells.rnConversely, there are many parts of the basin where LowerrnYacimiento El Trébol Formation is represented by silts andrnshales (west and south of Comodoro Rivadavia and betweenrnComodoro Rivadavia and Marta wells).rnSand rich fairways, represented by gross thickness isopachs,rnmap as trends that are perpendicular to the basin edges.rnLower Yacimiento El Trébol production is found in these thickrnsand areas, while in thin sand areas, production comes fromrnthe underlying Comodoro Rivadavia Fm.