Los Molles Formation in the Neuquén basin (Fig 1), west-central Argentina, contains a series of deep-water submarine channel complexes deposited in an elongate basin, during the Pliensbachian-Toarcian ages. These events developed during the final stages of the rifting phase. In the studied area, these submarine meandering canyons cut the shelf and gentle slope in a SSE-NNW direction, and represent the transfer zone of the system, where erosional features are more frequent and lithological distribution is more complex. The canyons are approximately 3 Km wide and several hundred meters thick and host a number of migrating channel-fill units inside, lying on erosional surfaces that cut into adjacent interchannel facies.

Applying neural network techniques in the three wells that penetrate this deep-marine strata, allowed the identification of five main lithofacies: muddy-matrix conglomerates, sandy-matrix conglomerates, coarse-grained sandstones, fine-grained sandstones and mudstones. Furthermore, the use of 3D seismic attributes was crucial to obtain the distribution of these facies within the canyons. For this purpose, techniques based on neural network and representative supervised "seed points" next to each lithology around the well, were applied.

This work resulted in a seismic volume with the distribution of four seismic facies along the system in a very heterogeneous way. The fine grained facies clearly located in an overbank position; the sandstones and conglomerates show a distribution constrained inside the canyons, and is also easy to see how the net-to-gross relationship increases towards the distal positions of the system.

The techniques applied, greatly improve the success of prediction of potential reservoirs locations.

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