Semi-Submersible is one of the drilling rig design concepts for offshore shallow water environments.

1. Water depth range: 30 – 1000m

2. Environmental Impact low

3. Not suitable for ice

4. Suitable for exploration and development. Easily moved between locations. Rig up time, essentially zero. Wells will be sub-sea completions – more costly and may still need local installation for process etc.

5. Extensively used in the southern Caspian sea. Not recommended to refurbish and existing rig. Will probably need to be manufactured outside and imported.

6. Flexibility with rig specifications.

 86-semi sub

Other drilling rig design concepts for shallow water depth environments will include:

1. Land rig on artificial island

2. Land rig on barge (with optional submerged caissons)

3. Swamp Barge (With Optional Submerged Caissons)

4. Standard Jack-Up

5. Shallow Draft Jack-Up

6.Semi-Submersible

7. Cantilever Drilling Barge

8. Steel Caisson with Drilling Rig

9. Modularised and Pile Elevated Drilling Rig

10. Drilling Rig on Pre-Installed Piles and Modules

11. Jacket Supported Offshore Rig

12. Posted Barge With Land Or Modular Rig

13. Heli-Rig

14. Submersible