Abstract
Future exploitation strategies sensibilities were based on accelerated natural depletion or different schemes for pressure maintenance by gas injection.
Since there were not PVT's analysis available for the gas condensate region of the S3M/SG-44 reservoir, a flash was estimated for the equilibrium liquid composition in order to reproduce the gas zone properties. Daily oil production rates were input data for the COMPSIM production rates were input data for the COMPSIM simulator, and daily gas production, GOR and reservoir pressure were history latched. Sensibility studies were similar to those conducted for the M3U/MVR-52 reservoir.
GEOLOGICAL DESCRIPTION
Reservoir M3U/MVR-52 in the MATA-R/Zapatos field and S3M/SG-44 in the Mapiri field are located, as shown in Figure 1, in the Greater Oficina Area of the eastern Venezuela sedimentary basin. Geologically, they fore part of a regionally identified monocline, with a smooth dip to the north.
The M3U sand, MVR-52 reservoir belongs to the lower section of the Oficina formation. In the fluvial deltaic depositional environment of the area, sand bars are present towards the north, and distributary channels towards the south-east.
The sand shows good development towards the eastern part of the reservoir, thinning in the center, and good development, with poor sand quality toward the western pert of the reservoir.
The reservoir is bounded to the south by a normal east to west striking fault, lateral pinchouts to the east and to the west, and by a pinchouts to the east and to the west, and by a water-gas condensate contact to the north, Fig.2
Abstract
The effects of gas injection into two gas condensate reservoirs in eastern Venezuela were analyzed in order to establish optimum exploitation schemes. One of the reservoirs, the M3U sand, MVR-52, in the Zapatos field, is actually subjected to a pressure maintenance process. The other reservoir, the S3M sand, process. The other reservoir, the S3M sand, SG-44, in the Mapiri field, is a dual gas condensate, black oil reservoir, currently at a primary depletion stage. primary depletion stage. Sensibility studies were made for both accelerated natural depletion and pressure maintenance through the injection of lean gas. These simulation studies were made utilizing a phase behavior simulator and a compositional phase behavior simulator and a compositional simulator (COMPSIM). The first was used to calculate equilibrium constants at different pressure. In order to achieve this, it was pressure. In order to achieve this, it was necessary to characterize the fluids in function of six (6) pseudocomponents, which represent the mixture of the pure components as given by PVT analysis.
COMPSIM is a three-dimensional, three-phase, compositional simulator, which allows to compute pressure and saturation distributions, as well pressure and saturation distributions, as well as the distribution of the fluid components in the oil gas-condensate phases. Mass exchange of each component between oil and gas phases is ruled by the equilibrium constants under conditions of thermodynamic equilibrium.
In the case of the M3U/MVR-52, after introducing pseudocomponents for the characterization of pseudocomponents for the characterization of initial fluid compositions, the dew point pressure, liquids deposition and relative pressure, liquids deposition and relative vol-es were latched using the compositional phase simulator. Production and pressure history phase simulator. Production and pressure history matching were attained through the COMPSIM.