Our Most Advanced System Ever Created

The Airlock® G casing buoyancy sub offers the same functionality as our original NCS Airlock® system, which recently surpassed 10,000 runs. The AirLock® G buoyancy sub contains a pressure barrier that allows the vertical casing section to be filled with fluid, while the lateral section remains air-filled and buoyant, reducing friction by as much as 50%.

Airlock® G operation is simple and passive. The buoyancy sub is installed in the casing string at a location calculated to provide the optimum balance of lateral buoyancy and the weight of the vertical fluid.

  • Calibrated shear ring ensures predictable operation

  • Unrestricted ID after operation

  • Sub can be torqued through

Our Most Advanced System Ever Created

The sub houses a high-strength, glass disk supported by a calibrated shear ring. After casing lands, increased surface pressure causes the disk to shatter and diffuse into the well fluid, leaving a full-drift ID. Circulation and cementing operations proceed as normal.

AirLock® G Specifications

Nominal size, in. / mm

5.5 / 139.7

Casing weight, lb/ft / kg/m

20-23 / 29.76-34.23

OD, in. / mm

6.500 / 165.10

Full API Drift ID in. / mm

4.775 / 121.3

Service end threads

Per customer spec

Minimum shear pressure, psi / MPa

5,500 / 37.9

Maximum shear pressure, psi / MPa

9,500 / 65.5.6

Shear increments, psi / MPa

500 / 3.45

Disk pressure rating (static), psi / MPa

10,000 / 68.95

Temperature rating, °F / °C

302 / 150

Average debris particle size, in. / mm

0.0625 / 1.588

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