History of Exploration and Development of the Controversial Giant Poza Rica Field Complex, Tampico-Misantla Basin, Mexico.

Abstract

Abstract

The Poza Rica Field Complex has seen a history of controversy, both geological and political. The largest field in a trend of over 20 individual large and small fields, it has produced approximately 1.4 Bbls of oil and 1.8 Tcf of gas. Shell discovered the field in 1930 by drilling on the crest of a torsion balance gravity anomaly. The accumulation was interpreted to be a giant stratigraphic trap in which the reservoir rocks are limestones rich in rudist material, dolomitized in parts and highly productive. Some thought the reservoir rocks had been faulted down from the Golden Lane trend, others believed they had been eroded off the nearby Golden Lane reefs. The town of Poza Rica quickly grew up over the field; it played an important role during the nationalization of the oil companies. PEMEX drilled down the southeast flank and continued to find productive wells, unexplainably below the main field's oil-water contact. Post-war compensation based on production from the field was granted to Shell. But after an early water-flood gave poor results, a detailed reservoir study was undertaken. This work supported the interpretation that the limestones had been derived from the Golden Lane rudist reefs, eroded and slumped down the platform slope. This interpretation was supported by the absence of major downthrown faulting on early reflection seismic records. However, not everyone agrees with this interpretation even today. Modern 3D seismic has better defined the internal geometry of the reservoir on the basis of which multi- layered reservoir models have been built. Now the question is what kind of EOR can be undertaken safely to extract the remaining hydrocarbons, estimated at up to 1.5 Bbls of oil and 2 Tcf of gas, in a field whose surface has been densely populated?

AAPG Datapages/Search and Discovery Article #90260 © 2016 AAPG/SEG International Conference & Exhibition, Cancun, Mexico, September 6-9, 2016