Saturday, May 3, 2008
Basic Drilling Concepts: Bit and Mud
Drill Bit: Drilling Engineer optimizes design by picking the best bit for the work. Different formation requires different type of bit usage. The most important parameter is cost per meter, a DE must be able to minimize cost per meter to maximize the cost effectiveness.
Once cuttings (chipped formation from bit cutting action) are produced, it is necessary to 'clean the hole' (transport cuttings to surface). The use of 'mud' (drilling fluid) is essential to: transport cuttings, keep the bit cool (the deeper it is, the higher the temperature. heat is also generated from rotation and vibration), softens the formation to make drilling easier and lubricates the well to ease 'casing running' (installing tubulars in drilled well).
The circulation system starts from 'mud pits' where mud is mixed (mud has different ingredients and chemicals to behave according to a DE's design in terms of viscosity, weight, gel strength and others). Mud is pumped using big pumps called mud pumps (wow what a technical term) and circulated up the derrick (in the stand pipe), down the top drive, into the ID (inner diameter) of the drill pipe, out the bit, up the annulus, back to the pits.
KMC or Kota Mineral Chemicals is one of the best local companies providing this product. The company is owned by Scomi and is now known as Scomi OilTools. The other big mud company is MI Swaco. MI is partly owned by Schlumberger and Smith International.