High-Resolution Correlation of Gulf of Mexico Pliocene-Pleistocene Sands

G. M. Ragan, W. H. Abbott

Correlating individual sands is critical to field development and reservoir management. High-resolution biostratigraphy can provide this correlation. Bioevents identified in the hemipelagic muds, provide an additional framework for calibrating seismic record sections. Applying this high-resolution data set can reduce the risk in development drilling.

Regional extinction data, typically separated by hundreds or even thousands of feet, permit calibration of regional mapping horizons between which reservoir objectives most often occur. New studies in the Gulf of Mexico Pliocene-Pleistocene reveal local and semiregional signals between regional extinctions. These signals, or events, are caused by physical and/or chemical fluctuations in oceanic water masses through time. Planktonic assemblages reflect and imprint this signal on the accumulating sediments. Identifying and documenting these events is the principal behind high-resolution biostratigraphy. Plotted on electric logs and seismic sections, such signals allow for refined correlation and subdivision of sediment packages.

From conventional well cuttings, we present high-resolution biostratigraphic analyses from two fields in the High Island and Green Canyon areas. Biostratigraphic events have been identified and local zonations established through the sand-rich productive intervals of both fields. Individual sands and sandy intervals are correlated using this technique.

AAPG Search and Discovery Article #91022©1989 AAPG Annual Convention, April 23-26, 1989, San Antonio, Texas.