The table slides up and down to accomodate the material you are drilling.

Drilling capacity in steel

Tapping in steel

Taper in spindle nose

Spindle speed range

Number of spindle

Spindle feed range

No of feeds

Distance of spindle axis from column surface with spindle

Distance between spindle face & floor level

Rotation of arm around column

Angle of drill head swivel from horizontal

Power of spindle motor

Distance between drilling spindle axis in horizontal

Column traverse along bed

Speed of column traverse along bed

Total weight of the machine

a core sample

In Drilling terminology, hydrostatic pressure is "The pressure exerted on a column of fluid at rest". This said, an oil well is just a column of fluid. Hydrostatic pressure is used to control the formation pressure in a well in order to prevent a "kick" (an influx of fluid into the well bore) or a blow-out (an uncontrolled influx of fluid into the well bore). Hydrostatic Pressure is calculated by a simple calculation = depth in meters x weight of drilling fluid in kg/m3 x gravity constant of 0.00981. IE. drilling at a depth of 3459m with drilling fluid that weighs 1120 kg/m3 would give you a Hydrostatic pressure of 38005 kpa. This is the amount of pressure that is being exerted on the formation at 3459m

Semi-submersibles are preferred for drilling to drillships because of their stability. They are only lowered in the water during drilling. Their ability to float on water makes transportation of rigs easier. The two types of semi-submersibles are bottle-type semisubs and column-stabilized semisubs.