TMK EXD is a connection suitable for extreme conditions.
The innovative high-torque double-shoulder connection TMK EXD has been developed using new modern technologies. Application of TMK EXD tool joints is reasonable for pipes of high strength groups for optimal use of drilling pipe capabilities.
The pin shoulder receiving the incoming torque provides the primary seal and tightening of threads to full recommended torque, and the box shoulder receiving the additional torque ensures the high torsional strength.
This connection has a modified thread profile in comparison with the standard structure, which makes the line-up of the pipe easier and allows for significant reduction of thread wear while the pin comes into engagement with the box during a drilling string assembly and subsequent make-up.
- The thread root is ellipsis-shaped, which reduces stress concentration and increases fatigue resistance.
- Increased stab flank angle
- Increased thread pitch
Optimal design of the tool joint helps to minimize the risk of thread seizure during multiple make-up and break-out operations, hence it minimizes the necessity of frequent rethreading.
The design of TMK EXD tool joints enables for use of enlarged inner passage without change of outer diameter and torsional strength of the drilling tool joint.
The reduction of tool joint outer diameter helps to improve operations efficiency, and the increase of tool joint inner diameter contributes to the reduction of pressure losses and retention of high performance parameters. These modifications of the tool joint allow for changing the inner and outer diameters to improve the hydraulic parameters of the pipe.
Below you can see the example of the tool joint connections optimization** for a pipe of Ø88,9 mm
** These parameters apply only to the API and TMK connections indicated in the table.
Application of TMK EXD high-torque tool joints provides for the required uniform strength of the structure of high-strength drilling pipes structure indicated in the API standard.
(the relation of tool joint and pipe torques must exceed 0.8).