Technical Bulletin 3
Latest Version of Blaise – Version 1.23
The latest version of the program, v1.23, has a few fundamental changes and also some underlying
cosmetic changes which will not be noticeable to the user. The main updates are:
Validation of TVD data and curve/grid scales
Increased choice of pressure gradient units. Choose from g/cc EMW, ppg EMW, psi/ft,
psi/1000ft, kPa/m, MPa/m, Mpa/Km and bar/km
Increased choice of pressure units - kPa, psi, MPa, Bar or atmospheres
User definable normal pressure gradient (or equivalent mudweight)
Tidying up of background processes
All these changes are in response to user feedback and suggestions.
Blaise Validation Checks
What is the process? Each time the validation process is run the following checks are made:
TVD always greater than 0
TVD always less than or equal to measured depth
TVD always increasing
DXC is in track 2
DXC matches the grid
Sonic is in track 3
Sonic matches the grid
Resistivity is in track 4
Resistivity matches the grid
Pressure Points are in range
OBG in range
OBG in track 6
OBG matches Pressure Points
FPG in range
FPG in track 6
OBG matches Pressure Points
PPG in range
PPG in track 6
OBG matches Pressure Points
These checks are automatically made when you open an existing well or can be manually done by
using the ‘Validate’ button bar object in the Master Module. The process does not run when a well
is first created as there is obviously no data to validate.
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Each time the process is run the following dialog box is presented.
It consists of three sections. The upper text box lists all the checks performed. The results of these
tests are found in the lower two text boxes named ‘Warnings’ and ‘Errors’.
Warnings indicate that there are some minor validation errors which should be corrected but are
not critical to operation. They usually involve changing either data or grid ranges and mean that
data are correct but will probably not be displayed correctly.
Errors, however, need to be addressed straightaway as the problem will directly affect the correct
running of the program or will lead to inaccurate data if not corrected.
Errors and warnings are generally easily corrected and can be re-checked by clicking on the
Validate button in the Master Module.
Further TVD Validation
TVD calculation is vital in pressure calculations and is a key part of the Blaise program. Virtually
all parts of the programme depend on an accurate TVD curve or correct data. Any problems with
data that are entered will seriously affect the correct functioning of the programme.
To minimise any problems that may occur we have included further TVD validation checks
whenever data are entered into the Well Data, True Vertical Depth option. The check will occur
as soon as the user clicks on the OK or Create TVD Curve buttons. Any problems will be reported
and should be corrected by editing the data.
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Pressure and Pressure Gradient Units
The vast majority of users tend to use equivalent mud weights as ‘pressure gradients’ (not strictly
technically correct but generally accepted) – these being ppg EMW and g/cc EMW. However, some
still like to use pressure gradients per se, such as psi/ft. kPa/m etc. We have thus changed the
program to cater for this requirement.
We have also changed the terminology slightly. The default ‘Primary’ units of the program are
metric and are metres, kilopascals, degrees centigrade and g/cc. This would be the case if all the
buttons were depressed or ‘on’ as shown in the figure below.
Button For Button ‘On’ – Button ‘Off’ –
Primary Units Secondary Units
M Depth Metres Feet
KPa Pressure KPa Psi
°C Temperature °C °F
g/cc Equivalent mud weight g/cc EMW ppg EMW
However, not everybody wants to use these defaults and we have now made it possible to choose
from lists of alternate pressure gradient and pressure units – called ‘Secondary’ units. By default the
‘standard’ secondary units are psi for pressure and ppg EMW for pressure gradient.
To change the secondary units for pressure gradient then click on Edit, Secondary Units, Pressure
Gradient and the following dialog box will be presented:
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Clicking on the appropriate ‘gradient’ button will change the currently used secondary unit. The
default settings will be displayed in the various boxes:
Units The currently selected secondary units
Units per g/cc The conversion factor from base unit of g/cc EMW
First trend line The value for the first EMW trend line after normal line when
EMW lines are displayed in Evaluation module
Trend Line Spacing The trend line spacing to be used if EMW lines are chosen for
display in Evaluation Module.
Note that these are default values but you can change them manually if you want.
You can also click on the ‘Save as Default for all wells’ to make your selection the default for all
subsequent wells you create.
Things to remember:
When you have set your secondary units the program should automatically convert the
appropriate pressure gradient curves whenever you click on the g/cc button.
You must make sure that all these curves are given the $PG ‘unit’ definition in the
appropriate PWD curve parameter set-up box.
You will need re-set the curve limits appropriately for the track for all the curves and for any
pressure point data
The new validation routine will indicate any problems with curves.
Secondary pressure units are handled in a similar way but are much simpler in their usage as there
are no equivalent EMW lines. Click on Edit, Secondary Units, Pressure and the following dialog
box will be presented:
Default secondary units are psi but you can choose another pressure unit by clicking on the
appropriate button. The default conversion factor from kPa is displayed in the second text box.
Again, you can choose to make this unit the default for all wells by clicking on the ‘Save as Default
for all wells’ button.
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Normal Pressure Gradient
Previously the program has assumed an average pore pressure gradient of 1.02 g/cc EMW. This is
still the default but, of course, there are regional variations from this value. Hence we have
introduced a dialog box where you can enter your particular regional gradient that will be used in all
subsequent calculations. The value can be changed by using the Edit, Regional Normal Pressure
You must enter the value in the units of currently used pressure gradient. For example if you are
currently using ppg EMW for your pressure gradient then you must enter the value here as ppg
EMW. This value will change whenever you click on the g/cc button. There is the option to save
this value as a default.
We have also taken the opportunity to tidy up some of the background routines. Many of these will
not be noticeable to the user. For example we found that an error occurred if a well that was the
currently used default well was deleted outside of the programme.
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