Characterization Study of Lower Lagunillas Member, Block IV, Lake Maracaibo. Application of Horizontal Well to Revive a Mature Oil Field
C. Coll, H. Gamero, Z. Jimenez, K. Leon, A. Leon, L. Ochoa,
R. Padron, L. Rondon, I. Bryant, B. Baygun, R. Ramamoorthy, R. Casco, S. Tariq,
and L. Stewart
The Lower Lagunillas is one of the largest reservoirs in Venezuela located in Block IV in the Lake Maracaibo Basin in Zulia State in Western Venezuela.The estimated remaining reserves are 270 MMSTB. A multidisciplinary, integrated reservoir characterization study was performed to evaluate reservoir heterogeneity and fluid flow dynamics in fine scale.
The majority of the remaining reserves are in the form of oil bypassed in the low resistivity pay zones. These zones were identified by the new core log calibration performed in this area. Significant pressure decline from the initial 4200 psi to 1400 psi has prompted us to explore new development strategy of selective drilling of horizontal wells. A key step in the study was acquisition and integration of new geoscience, well log and pressure data. The available geology, geophysics, sedimentology and petrophysics were integrated and loaded on to a 3-D visualization package for correlating and validating the various lithofacies with petrophysics and sedimentology. The resulting reservoir model was exported to a flow simulator for developing a dynamic simulation model. A target layer was selected based on the results of the characterization study and risk assessment strategy. A pilot well was drilled in the reservoir to acquire new data and information. These information were processed to evaluate the borehole stability, petrophysical properties, location of the fluid phases, pressure behavior and target zone. The processed data were utilized to confirm the location and to develop the completion diagram of the horizontal well.
AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California