Annular pressure
APWD
Downhole pressure through drilling and pumps-off periods.
A calibrated, temperature-compensated pressure instrument records average, peak and resting annular pressure alongside temperature and drilling dynamics. Sampling and measurement start times are programmable, with memory recording and real-time transmission.
- pressure accuracy
- 0.1% FS
- temperature rating
- 175°C
- module diameter
- 1.875 in
Measurements & capabilities
- Average, peak and resting annular pressure
- Pumps-off measurements and FIT support
- Annular temperature
- Axial and lateral shock/vibration measurements
- Programmable sampling and memory recording
Applications
- Equivalent circulating density evaluation
- Hole-cleaning and barite-sag analysis
- Leak-off and formation integrity testing
- Connection and pumps-off pressure review
MEASUREMENT IN CONTEXT
Measure the pressure inside the operating window.
APWD records annular pressure through drilling and pumps-off periods. Use measured pressure with the applicable drilling and geomechanical program; the operating window shown is conceptual, and pressure range must be confirmed for the selected configuration.
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Published technical parameters
System specifications
Module specifications
| Parameter | Published value |
|---|---|
| Module diameter | 1.875 in |
| Module length | 34.9 in |
| End connection | 10-pin Kintec |
| Maximum temperature | 175°C / 347°F |
| Accuracy | 0.1% full scale |
| Repeatability | 1 psi |
| Supported collar size range | 4.75–9.5 in |
| Pressure limit / transducer range | Confirm selected configuration |
The source lists 20,000 psi and 15,000–29,000 psi in a misaligned table. Neither is presented as a verified universal operating limit.
Measurement channels
| Group | Measurements |
|---|---|
| Pressure | Average, peak and resting |
| Temperature | Annular temperature |
| Vibration | Peak Z; peak X-Y; Z; X-Y |
| Event flags | Z/X-Y vibration; Z/X-Y shock |
| Counts | Z shock counts |
| Data availability | Eight real-time variables on legacy tools; source lists 14 total data points |
Calibration process
| Step | Source description |
|---|---|
| Calibration matrix | Seven pressures and eight temperatures |
| Thermal compensation | Two temperature sensors |
| Assembly calibration | Circuit board and transducer calibrated together |
| Conditioning | Pressure sensor and board burned in |
Calibration process does not replace the published 0.1% FS accuracy rating.
Technical documentation
APWD technical sheet
Reformatted specifications and application notes, with source qualifications retained. Technical-review edition; confirm the current assembly rating with MWD Solutions before use.