With the exception of the highly developed world class deposits in Venezuela, production of heavy oil is not common in South America. YPF S. A. (now Repsol YPF), the largest oil producer in Argentina, operated its Cerro Fortunoso heavy oil reservoir for a number of years using techniques primarily adapted from light oil reservoirs. The economic performance was sufficient for periodic expansion, and for construction of the surface infrastructure necessary to collect and pipeline the oil offsite for treatment.

Recently, YPF recognized the possibility that technology from the highly developed Canadian heavy oil industry could aid exploitation of the Cerro Fortunoso reservoir. This paper discusses the challenges and successes of the reservoir engineering portion of a multifaceted one-year project between Tecknica Overseas Ltd. of Calgary and YPF S.A.


The Cerro Fortunoso Field is located in the northwest portion of the Neuquen Basin of Argentina (Figure 1). Cerro Fortunoso was discovered in 1985, and first produced in 1986. Since that time, the project has been expanded to include over 120 wells(Figure 2). Cumulative oil production through June 1997 exceeded 1.5 million m3.

Multiple sand zones have been routinely completed, stimulated, and co-mingled for production of 14 to 17 ° API oil. Reciprocating pumps and pump jacks have generally been used, although gas lift has been used in several wells with high GOR's. Individual well production is gathered into two batteries using heated or buried flow lines. Field production is shipped by pipeline to a regional treating facility.

YPF contracted Teknica Overseas Ltd. to perform an in depth review of the Cerro Fortunoso project. One of the primary engineering goals was to determine how engineering technology from the mature Western Canadian heavy oil industry could be applied to improve contains a summary of the results.


All the prior data, reports, and analyses for the Cerro Fortunoso Project were written in Spanish. This was overcome in two ways. YPF S. A. asssigned an engineer and a geologist with training in English to reside in Calgary for the duration of the study. Teknica employees received ongoing formal and informal training in Spanish. A dictionary of Spanish - English oil field terms was created and continually updated.

The units used to describe Cerro Fortunoso Project data were a combination of English, Metric, and European practice. Conversion Tables were created to allow data to be expressed in each system (Table 1).

Contacts with project staff in Argentina were established to obtain missing data and request additional information and tests. Email was effective for many tasks, but some locations did not have that capability. Faxes and telephone conversations were limited to high need occasions due to higher costs and occasional transmission problems. Overall, contact with field personal was not significantly different from that experienced working with remote Canadian projects.

Interaction between the two groups was excellent. No cultural difficulties occurred.


The geology and petrophysics of the Upper Cretaceous Neuquen Group reservoir at Cerro Fortunoso are strikingly different from those in Lower Cretaceous Western Canadian heavy oil and bitumen reservoirs.

This content is only available via PDF.
You can access this article if you purchase or spend a download.