Abstract: Marcelina Formation Study--Maracaibo Basin
C. D'Arlach, J. Peralta, R. Murillo
Recent development activity onshore, west of the Maracaibo Lake, has led to a better understanding of the Paleocene Marcelina formation in the basin.
The Marcelina formation is divided into two sections, an upper coal dominated interval and a lower sand/claystone interval. The sandstone reservoir section consists of a number of fining upward sequences deposited in a fluvial environment. Laterally the section evolves to a shallow marine shaly and carbonatic section, or is truncated by a regional unconformity, being missing over much of the Lake area. The Marcelina sands are only commercially productive in the Alturitas Field, where oil is found in a combined stratigraphic/structural trap.
This paper focuses on two aspects of the Marcelina. First, the study incorporates the field data into a regional framework to investigate the possibility of similar plays in the studied area. Second, the study integrates geology and engineering data to examine the Marcelina as a reservoir unit to optimize field development and increase the oil recovery efficiency. Information from seismic, logs, cores, reservoir pressures, and fluids is used to understand the depositional model and the field complexity.
The study provides a model, supported by extensive data, which may help to develop other potential discoveries in the west coast area.
AAPG Search and Discovery Article #90951©1996 AAPG International Conference and Exhibition, Caracas, Venezuela