History Until the 1900's, most oil wells were created using percussion drills - technology already in use by the Chinese in 1100 BC and still a very popular method of drilling for water. A percussion drill is a pole with a heavy piece of metal on the bottom. It is lifted and dropped repeatedly into a hole, gradually making it deeper. Many men working together often took many years to make a single well this way. The work is now usually done with engines. Throughout the 19th and 20th centuries, improvements in steel technology provided rotating drill bits that could quickly cut through soft rocks. Even in soft rocks, steel can be worn down very rapidly, so it is often covered with inserts, or a complete outside layer, of tungsten carbide, which is more brittle than steel, but has greater resistance to erosion. If this is not enough, synthetic diamonds are added, but the hardest rocks can only be drilled with the help of real diamonds. Geologist first used natural diamond for drilling in around 1910, Diamonds were first introduced to full-hole bits for oil wells in the early 1920s and are widely used today. Before the early 1900s, drilling equipment was spun using livestock and a wooden wheel, but now, the rotating equipment is put in motion by a rotary table, which is connected to a square-shaped hollow stem, called a Kelly. In percussion method the drilling method involved repeatedly dropping a heavy weight to crush the rocks and make a well, this method rather than being very old and inefficient it takes more time and more men power and also it’s not capable of reaching the deep layers, so without any question the rotary method is better and much faster.
The end of the drill string is attached to a body called the Bit which responsible of crushing and breaking the rock formations as it penetrates the different layers of earth’s crust. It’s designed in such way that enables it to works efficiently through the soft and hard formations of...