Real Time Monitoring of Plug Barriers during Long Time Suspension for Temporary P&A

Challenge

The client needed to perform Temporary P&A of a well located in the Norwegian continental shelf. In addition the operator will remove the Xmas tree for it to be refurbished and used on another location. The operator planned to set two barrier plugs to temporarily abandon the well; one shallow- and one deep-set plug. The planned suspension time for the well were estimated to be 3-5 years.  Monitoring of the barrier integrity was required in order to comply with industry regulations and to execute this operation in a safe manner.

It was a necessity to place one barrier plug above the Down Hole Safety Valve (DHSV) and one additional deep set barrier plug close to the reservoir. The shallow plug was planned to be run on e-line and set with an electromechanical setting tool.

The well is located on an unmanned platform. The operational plan required to monitor pressure data from below the shallow set plug and to be able to visualize it in real time onshore for a minimum period of 5 years.

Solution

Monitoring would be provided by connecting a 3.60in OD Iconic Digital Transponder (iDT) to the shallow e-line set plug, where the iDT would capture live well pressure data and deliver that wirelessly to surface recording at the wellhead. In addition, the wellhead transponder communication was integrated into the installation’s SAS/control facilities enabling live data access from facilities onshore.

Operation

First, the deep set plug was set and leak tested from above. The shallow set plug was run and set at 93m below the wellhead and top and leak tested from above.

During the leak test of the newly installed shallow barrier, the iDT continuously transmitted pressure and temperature data to surface connected to the wellhead with a sampling rate of 2 minutes. The signals were picked up and displayed on the ICONIC surface logging system.

After the xmas tree was removed, an interface between the ICONIC surface transponder, connected to the Wellhead, and the operators control system was established . At this point, the sampling rate from the iDT was coded at 12 hours intervals in order to guarantee data sampling across the duration of the planned suspension period . The iDT performed at a high level of accuracy during installation and continues to perform real time barrier integrity monitoring.

Value Created

Installing below barrier monitoring using iDT needed no additional runs. The iDT provides data with no material increase in operational complexity. Barrier status can be monitored continuously, and remotely, due to the interface between the wellhead transponder and the operators control system and ultimately live data access from onshore. iDT was installed in a well in an unmanned platform so live barrier data improves operator decision making and reduces overall operational burden on the asset.

Case information

Overview

The client needed to perform Temporary P&A of a well located in the Norwegian continental shelf. In addition the operator will remove the Xmas tree for it to be refurbished and used on another location. The operator planned to set two barrier plugs to temporarily abandon the well; one shallow- and one deep-set plug. The planned suspension time for the well were estimated to be 3-5 years. Monitoring of the barrier integrity was required in order to comply with industry regulations and to execute this operation in a safe manner.

Product

Iconic Digital Transponder - iDT

Purpose

Completed

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