This paper presents the building of a geocellular static model of El Furrial, giant oil field in Venezuela. El Furrial field, located in the north of Monagas state, was discovered in 1986. It originally contained about 7 billion STOIIP. The field is approximately 13 km along strike and 7 km wide. It produces from two reservoirs identified as the Naricual and Los Jabillos Formations. The gross thickness of the two reservoirs is about 2500 ft. The oil composition in the Furrial Field changes rapidly with depth from that of a conventional oil (28 °API) at the top of the formation to that of an immovable tar mat, principally as a result of an increasing alphaltene content of the crude. This full field model is set in highly structural complex reservoir. A new software's chain, RML (Reservoir Modelling Line) was used and has allowed to build an accurate 3D model respecting the most important geological constrains of the field data. Five separated but integrated applications allow to take into account complex structural setting as well as petrophysical data and a high diversity of sedimentological environments which composed the reservoir. Two first applications (GeoSurf and GeoSim) are used to build an accurate structural framework integrating complex surfaces and more than 60 main faults. A new simulation option (Pluri gaussian algorithm) of stochastic application (Heresim) provides a better solution to restore complex channel or bar architecture and to attribute properties parameters. The resulting very high resolution geocellular grid (about 350 million of cells), have been successful up scaled in term of rock type, porosity and permeability with the 2 last applications (SimGrid and SimUp) to obtain a coarse model of about 900 thousand cells to be used in dynamic simulations. Using such a line of applications had permitted to get a very integrated model and to be secure of the existence of a very close link between the resulting static and dynamic models. Introduction El Furrial field is set up in the external foothills of Oriental Basin of Venezuela at NW of Monagas province (Fig. 1). It is located in the state of Monagas, Venezuela, approximately 25 km West of Maturin city, and was discovered by the FUL-1 well in February 1986. This well was completed in the Upper Tertiary Naricual Formation. The initial oil in place (STOIIP) is estimated in the Naricual Formation to be about 7 billion STB. The API gravity for the FUL-1 oil was 28°API. The initial reservoir pressure was 11258 psi at 13800 feet subsea, and at the average reservoir temperature (approximately 300°F), this indicates the reservoir was initially over-pressured. Initially, the production mechanism was natural depletion under rock-fluids expansion. The field produced from two reservoirs identified as the Naricual (Tertiary age) and the Los Jabillos (Cretaceous age) Formations. The gross thickness of the two reservoirs is about 2500 ft. The average porosity is 13% and the average permeability is around 300 md. Today the field has 113 production wells (163 production strings), 44 water injection wells and 7 gas injection wells. Present production rate is about 400 MBOPD. The cumulative production is 1600 MMSTB. The average reservoir pressure is at 6500 psi. A new software solution, RML (Reservoir Modelling Line) is applied to build a full field geocellular model. Using this chain of applications allow to elaborate a very realistic 3D structural model which can be used as a guide to build an accurate high resolution grid. This high resolution grid can then be filled by results from the HERESIM's stochastic application. The two last applications are subsequentially used to define a coarser grid adapted to run dynamic field simulations and for up scaling different parameters of the model respectively.

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThis paper presents the building of a geocellular static model of El Furrial, giant oil field in Venezuela. El Furrial field, located in the north of Monagas state, was discovered in 1986. It originally contained about 7 billion STOIIP. The field is approximately 13 km along strike and 7 km wide. It produces from two reservoirs identified as the Naricual and Los Jabillos Formations. The gross thickness of the two reservoirs is about 2500 ft. The oil composition in the Furrial Field changes rapidly with depth from that of a conventional oil (28 °API) at the top of the formation to that of an immovable tar mat, principally as a result of an increasing alphaltene content of the crude.Using such a line of applications had permitted to get a very integrated model and to be secure of the existence of a very close link between the resulting static and dynamic models.