f Rediscovering Main Cape after 47 Years, Offshore Honduras in the Mosquitia Basin

The Mosquitia Basin located on the Chortis Block offshore Honduras and Nicaragua was an active exploration area in the 1970’s with over 30 exploration wells drilled, 75% of which recorded hydrocarbon shows. Exploration stopped for global political reasons in 1980 and only one offshore well has been drilled since.

Several wells flowed oil in the basin and Main Cape 1 was drilled by Unocal in 1973 and found oil in Middle Eocene carbonate reservoirs. Seismic mapping and a detailed integration of paleo-depositional environments with petrophysics and DST test analysis now illuminates the hydrocarbon potential of the Main Cape structure and points to the necessary appraisal steps and key challenges to making this a commercial oil development to the benefit of Honduras.

The petroleum system of the Mosquitia Basin is inextricably linked to the evolution of the Caribbean plate. The targeted reservoirs are in the Middle Eocene, these carbonates seem to be influenced by local climatic and environmental condition. The high percentage of Miliolina fauna, the absence of planktonic foraminifera and Nannofossils reveal that these carbonates was deposited on a restricted carbonate platform in a very shallow marine hypersaline environment on a gently sloping ramp (inner ramp to mid ramp) with local reef patches. The upper part of the reservoir appears to have been deposited in a middle ramp setting where abundant Nummulites have been reported. The absence of Nummulites in the major portion of the Eocene sequence could indicate very warm (greater than approximately 31 °C) or warm-temperate (less than approximately 20°C) shallow-water environments that is exposed to salinity fluctuations.