Borehole drilling rigs are of different type, we have swap/sedimentary drilling rig and basement / rocky drilling rigs.
Swap /sedimentary drilling rig- this rig is majorly used in swap /sedimentary areas, it can also be used in rocky /basement area,
Basement /rocky areas drilling rig- they are the very popular ones you see around majorly used by most water drilling companies in nigeria and west africa because of our topographical formations, this type of rigs can penetrate any type of rock from the starting to more than 450meters depth, this rig can also drill in swap /sedimentary areas but it will consume more time.
The price of new ones range from N70m-N180m