Stochastic 3-D Modeling for the Giant Carito Full Field Compositional Simulation, Eastern Venezuelan Basin

 

Guaiquirian, Luis¹, Hector Marquez², Eduardo Labastida¹, Wilfredo Maestracci¹ (1) PDVSA, Puerto la Cruz, Venezuela (2) Roxar Inc, Puerto La Cruz, Venezuela

 

The Carito field is located in the northern part of Monagas State between Furrialand Santa Barbara fields. Its production started in 1988 by well MUC-1E. The fieldis defined as an asymmetrical anticlinal. The reservoirs present a considerablelevel of heterogeneity as a result of a combination of geological events, includingcomplex compressional faulting and a diversity of sedimentary environments.

Available data for this study include lithology and petrophysical well logs, 3Dseismic, core analysis and production history for both Oligocene and Cretaceousreservoirs.

A high resolution modeling grid was built using corner-point geometry. Reservoirproperties were distributed using stochastic 3D non-stationary modeling for both­facies and petrophysics.

Facies modeling was performed for each one of the ten genetic units, combiningTruncated gaussian simulation and Sequential Indicator Simulation tools to describesub-environments (large-scale heterogeneity), and sand/shale distributions insid-esub-environments (finer scale). The resulting realizations reproduced the conceptualsedi­mentologic model.

For petrophysical modeling, a Sequential Gaussian Simulation algorithm with trendswas used. Blocked well log data was inspected to check the distribution and spatialvariation of the petrophysical properties within each facies.

Fifteen realizations were produced and re-scaled in order to measure uncertainty.After flow simulation, the one with the best match to historical data was selectedas the most rep­resentative.

This is the first full-field geostatistical model to honor reservoir heterogeneity.It will be used in the dynamic modeling stage to plan the further development ofthe field and to max­imize oil recovery through water and gas injection processes.