Initialization view in GEM™
Initialization data is composed of one or more initialization regions for which pressure and depth, contact depth, water saturation, and other data is defined. Each initialization region may be associated with a different area of the simulation grid by adding initialization regions in this tab.
The master table for the Initialization view (located in the left panel of the view) contains a list of initialization regions:
Active Determines whether initialization region is active. Inactive regions are not written to the deck.
Name Name of the region.
Region ID ID of region used in the deck.
1. The Region ID must have a value greater than or equal to 1.
2. The active Region ID numbers must start with 1 and have values increasing by 1.
3. Active models must not have unique Region ID numbers.
Parameters tab
The Parameters tab of the Initialization view contains parameters that describe the selected initialization region.
Calculation method
VERTICAL (Vertical Equilibrium Selection) Controls the type of reservoir initialization calculation. Indicates that pressures are determined from the hydrostatic equation and saturations from the capillary pressure tables.Click on the button to open the Edits view to change your selections.
User specified input Specify pressure, composition and saturation of each grid block. Use this sub keyword only when the pressure and composition of each grid block need to be defined individually. This keyword replaces, and is exactly equivalent to the *VERTICAL *OFF option of earlier versions, which is still accepted by the GEM™ simulator.
Advanced parameters
Select the USER_INPUT option at the top of the view to access the advanced parameters.
Gas-Oil capillary pressure at the gas-oil contact (GOC_PC) Introduces the value of the oil-gas capillary pressure at the gas-oil contact. This value is used in the *VERTICAL *DEPTH_AVE initialization options.
Water-oil capillary pressure at the water-oil contact (WOC_PC) Introduces the value of water-oil capillary pressure at the oil-water contact. This value is used in the *VERTICAL *DEPTH_AVE initialization options.
Gas cap initialization (GASZONE) Specifies whether residual oil saturation is to be set initially in the uppermost part of the reservoir where the difference in the oil and gas phase pressures exceeds the largest tabulated value the oil-gas capillary pressure.
Initialization Region Parameters
The Initialization Region Parameters section contains two tables used to the initialization regions. The parameters are composed of one or more initialization regions. Each initialization region may be associated with a different area of the simulation grid and different depths of contact, reference pressures, etc, may be specified in each region.
Each row in the left hand table defines a region.
Region ID Region ID used internally, this is not generated in the deck.
Each cell in the right view defines the values for the initialization region.
Reference Pressure Indicates input of reference pressure. The reference pressure at the reference depth are used in the vertical equilibrium option, along with the capillary pressures, fluid densities, water-oil contact and the gas-oil contact depths, to calculate the block pressures and saturations.
Reference Depth Indicates input of reference depth.
Water-Oil contact (DWOC) Defines the depth to the water-oil plane.
Gas-Oil contact (DGOC) Defines the depth to the gas-oil contact plane.
Water-Gas contact (DWGC) Defines the depth to the water-gas contact in a reservoir in which no oil is present.
Water Saturation below Water-Oil Contact (SWOC) Indicates input of water saturation below the water-oil contact.
Gas capillary pressure at the gas-oil contact (GOC_PC) Value of the oil-gas capillary pressure at the gas-oil contact in the given initialization region.
Water-oil capillary pressure at the water-oil contact (WOC_PC) The value of the water-oil capillary pressure at the water-oil contact in the given initialization region.
Oil Zone Composition (ZOIL) Introduces input of oil zone compositions (one composition vector for each initialization region in the reservoir). Clicking the ellipsis button will open the tuple editor.
Gas Cap Composition (ZGAS) Introduces input of gas cap compositions. Clicking the ellipsis button will open the tuple editor.
Variation of Composition with Depth (ZDEPTH) Indicates the variation of composition with depth. Clicking the ellipsis button will open the tuple editor.