A-PRO Maximizing Production on SAP Well

A remote location well, capable of producing approx. 1500 stb/d, was suffering unplanned SAP. Consequently, there were a number of locations on the wellhead annulus side outlets (and their associated gate valves / pressure gauges) where only a single barrier existed, to the escape of the pressurized annulus fluid. This breached the OPCO’s well integrity policy. Concerns also existed that the SAP could, in time, approach the Maximum Allowable Annulus Surface Pressure (MAASP). The well was not connected to SCADA and regular OPCO staff visits were impractical. So, the well was to be shut in awaiting workover at a significant production deficit. 

Middle East’s first fully autonomous SAP management system – PTC’s A-PRO™A-PRO™ was installed on the well. The highly customizable A-PRO™, utilizes PTC’s VR Sense™ Annulus Pressure and Temperature (P&T) sensor and HSAS™ Annulus Safety Valve, to restore double barrier integrity in the well. 

In cases where SCADA and power is available at the wellsite, the VR Sense™ and HSAS™ can be integrated with existing facilities. However, in this case, the A-PRO™ system, with solar power, HPU system and GSM communication was required. 

The A-PRO™ data logger and control system continuously monitors  the P&T data measured by the VR Sense™. It also automatically manages the SAP between pre-set limits by opening / closing the HSAS™ Annulus Safety Valve, to facilitate annulus pressure blow down to the production flowline. The system also sends reports, warnings and alerts, via SMS and e mail to the control room and selected operations staff. 

• The A-PRO™ System was commissioned in June 2019, at which time the double barrier the VR Sense™ and HSAS™ created, vs the escape of pressurized fluid from the annulus was verified.
• The well has continued to be produced at ca. 1500 stb/d, instead of being closed in awaiting workover.
• The system continues to operate reliably, logging data locally every 5 minutes (and at blow down events), then sending compiled data in report format every 12 hours to the field central control room and to selected operations staff, by email and SMS. 
• The system has provided real time, annulus pressure and temperature data along with system status data ‘on demand’ via SMS, when prompted to do so by SMS message.
• After 15 months in operation, the SAP reached the blow down trigger pressure (700 psi) and the A-PRO™ system performed as per its design. The system opened the HSAS™, allowing the annulus pressure to be automatically blow down to 100 psi above the flowline pressure, before re-closing the HSAS™. 
• Having coincident Annulus Temperature data, along with the Annulus Pressure data, has proved to be very useful. An annulus pressure / temperature relationship ‘signature’ has been established. In this case:
  • There is a consistent shape to the pressure / temperature changes, every time the well starts flowing or is closed in. This indicates the communication causing the SAP is stable.
  • The Annulus Pressure increase is primarily due to the average temperature increase in the well , when the well is flowing.
  • The fluid driving the SAP, can only enter the annulus during periods when the well is closed in (when the average temperature in the annulus is lower and the SAP is relatively low).
  • When the well is flowing, the annulus heats up and the annulus pressure increases to a level, then stabilizes. This indicates that a balance point is reached where the source of the SAP is no longer leaking into the annulus when the well is flowing.
  • Annulus Temperature data gives a very clear indication when the well has unexpectedly stopped flowing (usually due to an unrelated downstream issue). This data has been used on 18 separate occasions in the first 15 months alone, to alert the Operations staff that for some reason the well was no longer flowing. This also contributed to optimizing the production uptime of the well.