WELL ABANDONMENT & BARRIER VERIFICATION
When conducting well suspension operations, ensuring the long-term pressure integrity of the barrier is critical. Typically, the barrier is leak tested by pressurising from above shortly after installation. However, these tests do not allow monitoring of the differential pressure across the barrier or any means of monitoring medium- or long-term hydraulic integrity.
Acoustic Data’s SonicGauge™ Plug Verification System can be deployed with mechanical plugs or metal barriers to instrument both the initial pressure testing and provide ongoing pressure measurement from both above and below the plug. The system can be configured to provide data over several years due to the technology operating on an ultra-low energy budget.
The SonicGauge can be deployed fixed to a third-party plug or independently on the Barracuda™ HEX-Hanger™ (high expansion gauge hanger). A corresponding SonicRepeater station with an onboard pressure transducer is often deployed on a HEX-Hanger above the plug to record pressure above the barrier. It also records the pressure data transmitted by the SonicGauge from under the barrier. Both sets of data are sent to surface in real time. If real-time reporting is not required, the SonicRepeater station can be retrieved by slickline from time to time to analyse the historical data saved to onboard memory.
The Barracuda™ product line also includes a HEX-Retainer™; a high expansion basket retainer that can be deployed by slickline through 2-7/8” tubing and set in up to 7” casing size. It is used to retain cement, frac sand, metal alloy, such as bismuth-tin (BiSn), and other plug materials.
CASE STUDY | REAL-TIME PLUG VERIFICATION
A SonicGauge™ Plug Verification System (PVS) was deployed in a well in by Multiline GmbH & Co. KG in Germany to monitor the integrity of a 7-5/8" Wireline Retrievable Bridge Plug (RBP) during a wellhead changeout. The wireless monitoring system provided under plug pressure data at surface in real time throughout the deployment.
The client requested the temporary installation of the SonicGauge PVS during wellhead replacement operations to provide real-time barrier integrity assurance at surface to ensure the safety of the maintenance crew and the environment.
A backup SonicGauge PVS system was installed via slickline on a Barracuda HEX-Hanger at 48 meters, and a primary SonicGauge PVS was attached directly to the bottom of the RBP which was installed at 21 meters. The primary and backup systems operated faultlessly over a 21-day operation, providing the client with a continuous stream of 10-minute pressure data confirming RBP pressure integrity.
CASE STUDY | INTER-BARRIER MONITORING
In a landmark first for the SonicGauge™ Plug Verification System, a SonicGauge sensor was deployed as part of a Retrievable Bridge Plug (RBP) assembly in order to demonstrate the ability to transmit across a barrier and monitor pressure between a lower and upper set plug during operations on the wellhead.
The client required a real-time wireless downhole gauge with surface read-out (SRO) of pressure below the upper plug, located at a depth of 70m. The goal was to provide this data directly to surface to allow the early identification of any pressure integrity issues while work was carried out on the wellhead.
Acoustic Data deployed the SonicGauge PVS directly to the bottom of the RBP. After deployment, real-time pressure data from underneath the plug was immediately received at surface from a depth of 70m, traversing the plug and the wellhead in a single hop. This demonstration proved the suitability of the wireless telemetry system for this application and its value in assuring safe operations.