Eccentric casing drilling system is today’s preferred method for drilling in difficult ground conditions, for example, where there are boulders or loose formations.EDS is the most economical solutions because its ingenious reaming wing the bit is retrievable can be used at the next hole. This is particularly design for shallow holes, as is often the case in water well drilling, geothermal wells and for shallow micro-piling work. EDS is ideal for short holes in consolidated overburden. The component of Eccentric system consists of Pilot bits, Reamer bits, Guide device and casing shoe.

When drilling, the reamer bit will rotate out to enlarge the hole which enough for the casing tube slide down behind the reamer. When reached required depth, the drill pipe will drill to the reverse direction and the reamer bit will retract, it is allowing the whole drilling system to pass through the casing.