(1) Bottom slip connection
1. Use WD slips to connect the surface casing;
2. Adopt BT type secondary seal structure;
3. No need to accurately calculate the running depth of the casing;
4. Not affected by environmental and climatic conditions;
5. Easy to install, fast, safe and reliable.
(2) Threaded connection at the bottom
1. The bottom can be connected to the surface casing with various specifications of threads, such as: CSG, LCSG, BCSG, TM, etc .;
2. The installation is convenient, rapid, safe and reliable.
(3) Bottom welding connection
1. The bottom is connected to the surface casing by sleeve welding;
2. Welding annulus is designed with pressure test holes to verify the welding effect.