• Special Connection designed for high bending and axial compression resistance. This is the only special clearance (aka semi or super flush) connection that is 100% joint efficient on heavy wall casing (i.e. wall thickness > 0.625" wall). The GB 2TT is used where downhole load conditions dictate casing with D/t between 10 and 12. Under severe axial compression loads associated with formation consolidation, casing so designed will accordion rather than buckle allowing servicing of the well. These types of strings are typically run as liners in critical sections of sub-salt wells.

Features

• Twin cantilever design reinforces the coupling limiting expansion and distortion from make-up, reducing assembly pre-stresses, and minimizing thread galling.

• Uses standard API and MRP gauges and procedures for inspection.

• Makes up to an internal torque shoulder and has API triangle stamp for secondary make-up verification on the rig. 

• 100% joint efficient under all load combinations. Will not jump out (or in) in high angle build sections common in directional drilling. 
• Maintains pressure integrity when special clearance.

Options

• Special Clearance OD (SC): Specify GB 2TT SC when ordering. See Data Sheets for minimum special clearance OD and associated properties.

• Modified (MOD): Specify GB 2TT MOD when ordering. Includes grooved couplings with seal rings.

• GB 2TT Couplings are available in the following casing sizes:
  7 5/8" OD, 47.10#, P-110
  7 5/8" OD, 53.20#, P-110
  9 5/8" OD, 70.30#, P-110
  Other sizes, weights and grades available on request. Minimum casing wall thickness is 0.625".