Aguada Pichana: Pushing the Limits Towards the Tight Sands

Régis Agut, Georgina Godino, Santiago D'Alessandro, Mariana Sainz Trapaga, and Emiliano Piovesanel
Geosciences, TOTAL Austral, Buenos Aires, Argentina

Aguada Pichana field is located in central part of the Neuquen Basin. The field produces gas and condensates from the sandstones of Mulichinco formation (Valanginian to Hauterivian), which is characterised by a relatively thick sedimentary column, ranging from 100 to 200 meters, with 20 to 60 meters of pay zone. In Aguada Pichana, the reservoir level being produced is composed of sandstones deposited in a fluvio-tidal to littoral environment, characterized by low to very low permeabilities, partly belonging to the Tight Gas Reservoirs category and thus requiring specific stimulations through hydraulic fractures.

The Aguada Pichana field development is evolving towards the production of lower permeability areas, clearly belonging to the Tight Gas Reservoir domain. In order to produce economically this gas, Total Austral with his Partners (YPF, Wiar, PAE) is carrying out an aggressive approach, mixing technological aspects & geological understanding.

The key to Tight Gas Reservoir in the context of Neuquen basin is twofold:

- Finding the “sweet spots”: using well calibrated seismic inversion as guide line, but with a strong geological knowledge which is fundamental to be predictive in terms of permeability. A fully integrated approach (local and regional, static and dynamic, diagenesis phenomena, rock typing, upscaling issues…) is the key to the understanding.

- Technological game change: breaking the limits of what is economically producible. Total Austral is working jointly with an R&D project of Total HQs on topics such as Advanced Hydraulic Fracturing, Horizontal wells with Multiple Hydraulic Fractures.

A way of achieving these objectives consists primarily in adapting the data acquisition program to the Non Conventional world of Tight Gas Reservoirs: special core analysis and microseismic monitoring are two typical examples of such an acquisition effort.

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