Build gross rock thickness grid
1. Open the Surface calculator (right click on a surface and select calculator) 2. Type in: GROSS ROCK = TOP HYDROCARBON BASE HYDROCARBON 3. This will produce a new GROSS ROCK grid 4. Clip negatives to a small negative number (reduces total Z-range)
B.Go to Operations Tab, Calculations folder, and select 2D and 3D area of surface.
C.(Multiply the resulting units squared number by the desired conversion factor).
Calculate volume between surfaces Areal calculations
– Inside polygon – For defined nodes in a grid
Surface operations
Surface Operations
Contains tools for manipulating on existing surfaces Rotate and smooth Extrapolate Expand and shrink Flip values Shift values Merge surfaces
Well
A
Volume processing (2D Grids)
Incorporate Fluid Contacts
1. Use grid or constant
2. Merge with a structure grid 3. Merging process
A. Copy structure to be merged
Remember: Only ONE undo!
Surface operatFra bibliotekons2D Volume processing; General procedure
A. Given top and base structure grids
B. Incorporate fluid contacts into top and/or base grids C. Build gross rock thickness grid D. Discount gross rock thickness by N:G, Phi, and (1-Sw)
A 3
+ 4
2
Volume processing (2D Grids)
Petrophysical parameters
Common petrophysical parameters are: – Net-to-gross – – Porosity Water saturation (used as 1-Sw)
Surface operations (2D grids)
Surface operations
Lecture and exercise purpose Purpose: Learn how to perform operations on surfaces and between
surfaces.
C
Volume processing (2D Grids)
Changing project units
Often Petrel’s default units are meters when the project units are feet. To change units: A.Click on projects in the Menu bar and select Settings B.Go to the Units Tab and make appropriate adjustments.
A B C
Gross
Net
Pore
Hydrocarbon
Volume processing (2D Grids)
Calculate volumes
There are three methods for calculating volumes
Between two surfaces
Between a surface and a plane
Volume processing (2D Grids)
Calculate Volumes – Volume/area versus depth
A. Double-click on the top horizon
B. Go to Operations tab, Calculations folder, and select Volume/area versus depth C. Specify min and max Z values (the depth interval to calculate volumes) and the increment to report the results D. Execute and inspect the result in the Petrel Message log. The result is also given as volume/area vs depth functions in the input tab. Volume/area versus depth
E. Calculate volume for positive thickness
F. Calculate area for positive thickness
D
C
A B
E F
Volume processing (2D Grids)
Top and base structure grids
A. Should define the zone of interest B. Should not contain missing node values over area of interest No volumes for missing nodes Fault gaps should be filled with nodes C. Should be tied to the top picks B C
Volume processing (2D Grids)
Calculate areas
There are two methods for calculating areas for an isochore grid.
Un-blanked grid cells Inside a polygon
Approximate area
Parameters represent average value for zone May be either constant or grid Z-range between 0.0 and 1.0 (ratio) – – If percent then divide by 100 If outside 0-1 range then clip
C. Pore thickness * (1 – Water saturation) = hydrocarbon pore thickness Note: For each step, copy the input thickness grid, rename it to the output thickness, and then perform the calculation.
A
Volume processing (2D Grids)
Calculate areas – inside a polygon
A.Go to Operations Tab->Convert Points/Polygons/Surfaces folder, and select Create Intersection with plane. Inside a polygon
Between two surfaces
Volume processing (2D Grids)
Calculate Volumes - between surface and a plane
A. Double-click on the top horizon B. Go to Operations tab, Calculations folder, and select Volume below surface (constant) C. Specify base level D. Execute and inspect the result in the Petrel Message log Between a surface and a plane
B.Display the polygons in a 2D or 3D window
Make sure they close Make sure they encompass the correct area C.In the Select/pick mode (arrow) touch a polygon to see its area, or Execute for Area and Length in Calculations for the Polygon.
Precise area (requires closed polygons)
Volume processing (2D Grids)
Calculate areas – un-blanked grid cells