Offshore El Salvador: the first interpretation of a unique 2-D seismic dataset and implications for a working petroleum system in a forearc basin setting

The unexplored Acajutla Basin is located within a forearc setting along the Pacific coast of El Salvador. It is a part of a larger system of forearc basins that lie between the coast of Central America and the Middle America Trench, running parallel to the Pacific coastline from central Mexico to Costa Rica. Interpretation of 3,700 kms of 2D seismic data reveal the presence of a deep depositional basin bounded on the northeast by the Central American Volcanic Arc and on the southwest by a basement ridge that forms a prospective anticlinal closure approximately 100 km offshore. The basin contains in excess of 9,000 m of mostly Mesozoic through Cenozoic sediments. In the Acajutla basin, seven sequence boundaries have been identified that are continuous and display high to moderate reflective amplitudes, encompassing Late Cretaceous through Pleistocene intervals. Structure contour and isochron maps are generated on mapped sequence boundaries correlated from adjacent regional well-tied seismic surveys offshore Nicaragua and Guatemala. Significant truncation and structural dip reversals have been mapped across the research area below the shelf edge at the outer arc high. Little drilling has taken place in the forearc basins of Central America; none whatsoever offshore El Salvador. Lack of success can be attributed to the complex tectonic evolution of forearc basins as it pertains to deposition of suitable source rocks, maturity, timing, and migration of hydrocarbons. The Corvina-2 well offshore Nicaragua, and the Esso Petrel-1 and Madre Vieja-1 offshore Guatemala aid in constraining lithological data in the region. Maturity data from regional studies indicate that source rock intervals have reached a stage of thermal maturity below a depth of 3,000m. Basin modeling indicates maturity across the forearc basins within varying geological units and depths. Research will focus on defining chronostratigraphic boundaries, thermal maturity models, and the overall tectonic and depositional evolution of the Acajutla Basin.

Name thesis:degree_name

Master of Science (M.S.)

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Geology and Geological Engineering

Grantor dc:publisher

Colorado School of Mines. Arthur Lakes Library

Year dc:date.issued

2023

Author dc:creator

• Branda, Alex N.

Advisor dc:contributor.advisor

• Trudgill, Bruce, 1964-

Committee members dc:contributor.committeemember

• Burton, Bradford
• Sonnenberg, Stephen A.

• Caribbean
• El Salvador
• Guatemala
• Middle America Trench
• Nicaragua
• seismic

Statement dc:rights

• Copyright of the original work is retained by the author.

Language dc:language.iso

eng, English

Identifier

T 9603

OAI identifier oai:identifier

oai:repository.mines.edu:11124/178662