Application | Failed PDHG Replacement



Permanent downhole monitoring of pressure and temperature greatly improves our understanding of reservoir performance and production enhancement opportunities. Traditionally this has been achieved with a cabled permanent downhole gauge (PDHG), which provides real-time data at a specific depth.

The loss of a cabled permanent downhole gauge (PDHG), due to issues such as splicing errors, broken cabled connectors, grounding out, sensor failure or during well service activities, can seriously impede a well operator’s ability to monitor and optimise a well’s performance. Traditional remediation methods require a potentially costly well intervention program which is often un-economic or impractical when considering both service costs and loss of production.

Acoustic Data’s SonicGauge™ Wireless Monitoring System can be retrofitted into a well where a cabled PDHG has failed or into new or brownfield developments where no monitoring was previously installed. The system has been designed to minimise installation costs with the Barracuda™ HEX-Hanger™ (high expansion gauge hanger) being installed via conventional slickline methods. The HEX-Hanger does not require a nipple profile, so the SonicGauge can be set virtually anywhere in the completion by the battery-powered Electro-SET™ (electro-mechanical setting tool).

Unlike a cabled PDHG that measures pressure and temperature at a single point in the tubing, SonicRepeater stations have onboard pressure transducers that allow the well’s flowing and static pressure gradients to be measured in real-time, an invaluable tool for real-time production optimisation.



  • Short- and long-term real-time reservoir monitoring solution
  • Replacement of a failed cabled gauge system (PDHG)
  • Real-time retrofit solution via slickline – no rig required
  • Brownfield optimisation programs


  • Real-time reservoir evaluation and production optimisation
  • Reduced risk and cost associated with memory gauge surveys
  • Real-time monitoring of Inflow Performance Relationship (IPR)
  • Real-time monitoring of flowing and static gradients in tubing


    The client has estimated that the installation of the SonicGauge™ Wireless Monitoring System will save millions of dollars across a 5-year installation period by removing the requirement to perform memory gauge surveys and shut in the well, leading to lost production.


  • SonicGauge™ Wireless Monitoring System
  • Barracuda™ HEX-Hanger™ (Gauge Hanger)
  • Barracuda™ Electro-SET™ (Setting Tool)


    The client is managing an ageing oilfield in which only 50% of active wells are equipped with Permanent Downhole Monitoring Systems (PDHMS). The Reservoir Team formulated a reservoir surveillance plan for the remaining production wells from which they required frequent downhole P&T data. They required a cost-effective real-time solution that would work over a multi-year duration and could be retrofitted to their existing well stock.


    Acoustic Data retrofitted a turnkey SonicGauge™ Wireless monitoring system in three slickline runs during a 12-hour period. The SonicGauge™ sensor and SonicRepeater stations were set in 4-1/2” tubing at depths of 800m (2,643ft), 500m (1,640ft) and 200m (656ft).

    The Barracuda™ HEX-Hanger™ technology is not reliant on nipple profiles for installation and allowed the gauges to be located at the exact depths required by the client. When the Barracuda™ Electro-SET™ (electro-mechanical setting tool) was recovered to surface after each run, the on-board data logs showed that the HEX-Hangers were optimally set.

    The SonicGauge™ System provides one data point every 6 hours with an expected system life of five years. Real-time downhole pressure and temperature data was immediately available at surface and viewed at Acoustic Data headquarters via the 4G-WiFi communication module located in the SonicGauge™ Data Logger, which was also patched into the customer's distributed control system (DCS) via a Modbus communication port.


  • Multi-year downhole-to-desktop data acquisition solution replaces failed PDHG and frequent memory gauge surveys
  • Real-time data was acquired during both high production rates (20mmscf) and during shut-in periods (pressure build-ups)
  • Considerable decrease in well intervention activity and the associated loss of production due to shut-in
  • Savings related to decreased lost production is estimated into the millions of dollars across a five-year installation period
  • Operational and personnel exposure at wellsite reduced, positively impacting Health, Safety and Environment (HSE)