Michael Dumestre¹
(1) City Investing Ltd. (AEC Ltd.), Quito, Ecuador

Abstract: The Fanny-18B field of Ecuador. How the application of 3D seismic and new geological thinking turned a small aging field into a major producing area

The Fanny-18B field is located on the eastern flank of the Oriente basin in Ecuador. The field was discovered in 1972 with the drilling of the Fanny 1 well, which tested 2191 BOPD from the Napo M1 formation. The M1 is a fluvial-estuarine complex of Campanian to Maastrichtian age, which subcrops a major Tertiary unconformity. Reservoir characteristics are excellent, with average porosity of 25% and permeability in the darcies. A total of 7 producing wells and one dry hole were drilled between 1973 and 1982, and production was initiated in 1978. Up to 1996, cumulative production had reached 23 million barrels of oil and daily production was around 4,000 BOPD.

In the summer of 1996 the first 3D program in Ecuador, covering 223 km2, was shot over the field and surrounding areas. It showed that the Fanny-18B pool is not controlled by a small structural high, but rather by a subtle feature interpreted as a clay filled channel, which cuts and isolates a large area of M1 sand development. Both amplitude and isochronal mapping were used to define this channel. A 29 well drilling program was initiated in October of 1996. All were successful in defining a large stratigraphically controlled pool, as well as discovering the Dorine field along the same trend defined by the updip channel seal. The current production of 42,000 BOPD is curtailed by pipeline restriction, and remaining recoverable reserves are in excess of 125 million barrels.

AAPG Search and Discovery Article #90914©2000 AAPG Annual Convention, New Orleans, Louisiana