The Tempa Rossa Field Static Modelling Case History (South Apennines - Italy)

Moge, Michel ²; Vanhalst, Mickael ²; Perrot, Jean ²; Botton-Dumay, Roselyne ¹
(1)Total SA, Pau, France. (2) Total E&P Italia, Roma, Italy.

For an ideal Oil Field life, number and quality of available data are supposed to be adequate to allow the Development decision to be based on initial Subsurface Models. Available data increase with time through acquisition (either static or dynamic) and then become the input of new Models used for optimization of production and reduction of uncertainties.

Compared to this ideal situation, the giant Tempa Rossa field (Cretaceous to early Tertiary extensive fractured Apulian carbonate Platform) discovered in 1989 and operated by Total E&P Italia in a joint venture with Shell and Exxon-Mobil, is an atypical case.

Considering its history, environment and technical specificities, this field has to be developed whereas many uncertainties still remain. Consequently, this constitutes one of its main challenges together with the need for additional Appraisal.

The field combines many complexities and heterogeneities:

- Structural complexity: detailed structural system is very poorly known, for lack of adequate imaging.

- Stratigraphic complexities: every possible type of heterogeneity may coexist over 200 km² and a carbonated reservoir thickness of 4,000 m to be modelled.

- Mediocre reservoir matrix characteristics: porosity < 1% in the limestones and only a few % in the dolomites.

- A very incompletely known fracturing system: several scales of fractures and heterogeneities but no geological driver to explain the distribution of the various fractures sets and their relative impact on the fluid flows.

- A complex fluid: heavy oil ranging from 24° API at the top down to 10° at the base of the proven column.

The new geological model is mainly based on conceptual principles in almost every domain. A further difficulty arises in the transition from “static model to dynamic model”, with the description of the fracture network. The different possible combinations of these concepts in various scenarios of dynamic models will eventually be challenged by their ability to match the existing set of dynamic data.

In parallel of the construction of a new static model, an operational phase started in 2010 by the drilling of a deep well named Gorgoglione-2. Even if many data acquisitions will still be necessary to reduce static and dynamic uncertainties, this well is a major step to firm-up the concepts and to improve the understanding of the Production mechanisms of Tempa Rossa field.

AAPG Search and Discovery Article #90135©2011 AAPG International Conference and Exhibition, Milan, Italy, 23-26 October 2011.