To enable and verify an installed barrier in any well with wireline intervention only. Removing the need for large pressure testing volumes or equipment to test installed barriers from surface. Especially when there potentially are structural issues in well barrier envelope that can limit the pressure test, inefficiencies or weak spots in the subsea structure or Xmas tree / well barrier envelope.
The wireline toolstring includes a setting tool with a monitoring system to log the setting signature of the plug.
A verification plug installed above the barrier with a verification module alters the pressure/forces below and sends the measured values to the setting tool above. The bespoke product setup provides a verified, documented barrier. Case history from a pilot job included to illustrate the principle.
The plug installation depth in the well is a compromise between requirements and verified structural integrity of the tubing, especially if installing a bridge plug as the primary barrier. The setting forces, anchoring and sealing signature of the plug is monitored and recorded. This individual signature will be verified against a library of ISO approved barrier installation profiles. Anomalies can be identified and trigger the need for a decision to release and relocate the plug. A verification plug may be installed near the primary plug. The verification plug installation signature will be surveyed in the same way as the primary plug to determine its proper installation. Verification is then achieved using the verification module between the installed plugs and logged by the setting tool above.
Pressure manipulation in the volume between two installed plugs will cause a load in the direction of flow on the lower primary plug and a (an industry standard) test from above by the verification plug. Upon completion, this operation produces the necessary documentation to leave the plug(s) as an approved barrier in the wellbore. Equipment is re-usable after re-setting at surface.
By documenting this sequence, we now have a lower plug verified as a barrier and can remove the verification plug above or leave it as a secondary tested and verified barrier if needed. All performed without needing to use large volumes of test medium from surface and waiting for thermal adaptation and fluid segregating to get a stable test readout at surface.
Number of Pages
Volume change calculation. J. Kopácek, J.. Šubert, Strojírenská výroba (1980)
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