Mississippi Canyon 194, Gulf of Mexico: Development Case History Geological Summary

Abstract

Mississippi Canyon 194 field (Cognac) was discovered in 1975 by Shell Offshore Inc. and its partners. Development was completed during 1981. Production to date totals in excess of 150 MMBE. During the last five years, production has been sufficient to impact geological interpretations of the field. Recently a 3-D geophysical survey was acquired, processed, and interpreted. This total data package of production, petrophysical, geological, and geophysical information has been used in planning a 20-well redevelopment program completed in 1990. The field is an anticlinal nose that plunges north from a major salt feature south of the field. The Cognac structure is situated in the downthrown block of a major south-dipping growth fault. The I, J, and K sands contain the majority of the hydrocarbons. These sands are part of a 1500-2000-ft thick section of Pliocene mini-basin deposits along the present-day shelf edge. Geological interpretations of the field include structural mapping of the pay horizons and gross and net sand isopachous maps. Mapping, in conjunction with core data, log shapes, and other geological indicators, has aided in determining environments of deposition. This paper will demonstrate how understanding the environment of deposition of reservoir sands has led to improved seismic interpretations. Subsequently, more » improved geological/geophysical interpretation led to drilling outstep wells where there were no direct hydrocarbon indicators. The vertical distribution of sands is also better understood as a result of this work. It is expected that this integrated approach to better understand the reservoir will lead to improved recovery. « less