Click to see subtopics:The Production editor can be used to perform pressure calculations along a wellbore. Another term for this is sandface pressure calculations, since the wellbore is used to calculate the pressure at the sandface from some reference pressure (for example, wellhead pressure or a gauge pressure). There are three main types of calculations that can be performed:
1. Production calculations
2. Injection calculations
3. Static calculations
For detailed information on pressure calculations, see calculations and correlations.
Triggering pressure calculations
To trigger pressure calculations manually, click the Calculate Sandface Pressure icon in the toolbar.
You can also calculate pressure automatically by importing production data (see get well data into Harmony Enterprise). For more information, see autocalc settings.
Starting pressure
All calculations use Active Pressure as the starting value. The active pressure is defined by your Pressure Source selection.
Production calculations
Production is defined as flow from the sandface (or reservoir) to the wellhead (surface). Consequently, if any of the gas, oil, condensate, or water production rates are positive, then the Production editor takes into account that the wellbore is producing.
Supported wellbore flow paths
All of the wellbore flow paths are supported for pressure calculations in the Production editor.
Injection calculations
Injection is defined as flow from the wellhead (surface) to the sandface (reservoir).
For the Production editor to account for injection:
- The production gas, oil, condensate, and water rates must all be zero (or blank).
- The injection gas or water rates must be positive.
In addition, in the Options dialog box, the Use Injection values in Sandface Calculations checkbox must be selected.
Supported wellbore flow paths
For injection, only these flow paths are supported for pressure calculations in the Production editor: tubing, annulus, both, and casing.
Note: Quiet-side calculations are not supported.
Static calculations
A static (or shut-in) wellbore is defined when no flow exists in the wellbore.
For the Production editor to take into account that the well is static:
- The production gas, oil, condensate, and water rates must all be zero (or blank).
- The injection gas or water rates must all be zero (or blank).
- And if a gas-lift flow path is selected, then the gas lift rate must be zero (or blank).
Supported wellbore flow paths
All of the wellbore flow paths are supported for static calculations in the Production editor.
- For the pumping flow path, the liquid level and gradient(s) are used to calculate the sandface pressure.
- For other flow paths, the wellbore is assumed to be filled with gas.
Note: Static calculations in the Production editor are different from calculations in the Static Pressure editor.