Page 297 - Petroleum Geology

field in Mexico, Poza Rica, discovered in 1930, lies to the west of the New
Golden Lane on what is known as the Tamabra trend. “Tamabra” is a corrup-
tion of Tamaulipas and Abra, and refers to the facies that is intermediate be-
tween the El Abra reefal facies to the east and the dense, micritic Tamaulipas
equivalent to the west. This facies is either a fore-reef detrital apron or a local
reef growth that did not persist. The general loss of permeability towards the
west and the variable permeability within the producing sequence both in-
fluence oil accumulation and account for reservoir variation. The Poza Rica
accumulation lies off the culmination of its trend, on the north-east flank
and south-east down a nose. It is not clear whether the apparently inclined
oil/water contact in this field is due to these facies changes or to a strong
hydrodynamic flow to the south-east.
The Marine Golden Lane fields lie rather deeper still, between two and
three kilometres, and discoveries are still being made. These fields also occur
in local culminations of the top surface of the El Abra, but few details have
been published.

h

-

miles 10
10 km

Fig. 12-10. Map of the Old, New, and Marine Golden Lanes, Mexico, showing the large
atoll form. (Adapted from Coogan et al., 1972, p. 1422, fig. 2.)