Abstract: Application of Sequence Stratigraphy in an Integrated Reservoir Characterization of the Miocene Lower Lagunillas Member in the Further Development of Blocks III/IV, Maracaibo Basin, Venezuela
H. Gamero De Vlllarroel, C. M. Coll, Z. Jimenez, T. Lozada, K. Leon, R. Brandt, R. Padron, L. Rondon, E. Gomez, M. A. Munoz, R. A. Ripple, B. A. Luneau
An integrated sequence stratigraphic framework has been developed for the Lower Lagunillas and Laguna members of the Miocene Lagunillas Formation at Blocks III/IV, Lake Maracaibo. These reservoirs were discovered in the 1950s and have produced over 1132 MMBO. The Lower Lagunillas and Laguna had traditionally been interpreted as delta plain and coastal bar deposits, with each member consisting of 3 reservoir subdivisions developed as single drainage units. Subsequent engineering studies showed that this geologic model did not adequately address the heterogeneity of the reservoirs.
Sedimentological interpretation of 8 cored wells led to the development of a new model which was further enhanced by integrating 210 well logs, 3D seismic data, petrophysical analysis, and production and pressure data. In this model the basal Lower Lagunillas is interpreted as a fluvially dominated upper delta plain. The upper part of the Lower Lagunillas and Laguna represents deposition in a tidally dominated lower delta plain and delta front environment. Fluctuations between tides and river floods were responsible for generating thick, very heterogeneous reservoirs.
The new reservoir model provides the basis for additional development by the identification of (1) recompletion intervals, (2) low resistivity pay zones as potential targets for horizontal wells, and (3) infill drilling targets. Use of this predictive reservoir model will ensure the optimal exploitation and recovery of the remaining oil at Blocks III/IV.
AAPG Search and Discovery Article #90951©1996 AAPG International Conference and Exhibition, Caracas, Venezuela