Slim hole well
For a slim hole casing design all the design loads, inclusive burst, collapse, and tensile load requirements, should be determined as for all other wells. For a fixed influx volume and assuming a single bubble of gas, the smaller annular cross section causes a greater influx height than in conventional holes. This might influence the casing setting depth and indicates the need for more sensitive kick detection techniques.
It is important, especially where non-standard casing sizes are introduced, that geometrical clearances, drilling hydraulics, and cementing hydraulics are closely examined:
Geometrical clearances