) button to add a row to the spreadsheet.Geothermal Gradient Section
Well Planning Report
The Geothermal Gradient section is used to define the geothermal gradient as a function of depth. This temperature profile is used as the default initial temperature state for all casing strings and is used to model circulation temperature profiles down the drillstring and up the annulus.
The Current Wellbore/Design picklist identifies the active wellbore/design for the data displayed in this section.
This section displays information for the wellbore/sidetrack selected in the Current Wellbore/Design picklist. Changing the selected wellbore/sidetrack updates the information displayed in the section.
Note: This section is read-only when the associated Design is locked or another application has the Design open.
This section contains the following tabs:
Note: This section is read-only when the associated Design is locked or another application has the Design open.
Use this section to record the temperature profile.
Surface Ambient Temp
For land wells, the surface ambient temperature is the temperature at MGL. For offshore wells, the surface ambient temperature represents the air temperature above MSL. The default surface ambient temperature is 80ºF.
Mudline Temp
The mudline temperature is displayed if the Offshore check box is activated on the Well Properties dialog. The water temperature profile will be linear between the surface ambient temperature at MSL and the specified temperature at the mudline. The default mudline temperature is 40ºF.
Entering data in the Temp at Well TD: <depth> TVD Area
The Temperature and Gradient options are mutually exclusive. Selecting the Temperature option disables the Gradient option, and vice versa.
The default temperature value at the well TD is computed using a 1.5º F/100 ft geothermal gradient.
Temperature Option Button
The temperature at the well TD can be explicitly specified or calculated using a specific gradient. To enter the value explicitly, select the Temperature option and enter the temperature at the TVD corresponding to the well TD.
Note: If the Temperature option is selected, the calculated gradient changes with variation in temperature at the surface for an onshore well or mudline for an offshore well, a change in TVD at the mudline or well TD, or a change in wellbore deviation.
Gradient Option Button
The temperature at the well TD can be calculated using a geothermal gradient. To calculate the value from a gradient, select the Gradient option and enter the geothermal gradient value appropriate for the area. The temperature at the well TD is then calculated based on the gradient and the surface ambient temperature at MGL for an onshore well, or the mudline temperature at the mudline depth for an offshore well.
The default geothermal gradient is 1.5º F/100 ft.
Note: If the Gradient option is selected, the calculated temperature changes with variation of temperature at the surface for an onshore well or mudline for an offshore well, a change in TVD at the mudline or well TD, or a change in wellbore deviation.
Use the spreadsheet to specify additional formation temperature data. These additional temperatures can be used to characterize a more complex formation or seawater temperature profile.
These temperatures must be entered against of TVD and must be entered in order of increasing depth. Intermediate temperatures are linearly interpolated between the nearest adjacent temperature specifications on the Standard tab.
Click the Add Row () button to add a row to the spreadsheet.
TVD
Specify a TVD corresponding to an additional temperature.
Temp
Specify an additional well temperature corresponding to a specified true vertical depth.
Locked check box
The Locked check box appears at the bottom of the Geothermal Gradient section. This check box indicates whether the associated Design has been locked. If activated, the Design is locked and the fields in the section can no longer be modified. A Design can be locked or unlocked through the Design Properties dialog accessed through the Engineer's Desktop™ applications, such as PROFILE™, COMPASS™, CasingSeat™ and StressCheck™.
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