To dig through the Earth's crust, rotary drilling uses a rotating drill bit. The rotary drill bit works in a similar way to a hand-held drill. It can penetrate even the hardest rocks. According to archeological evidence, the Egyptians used a similar technique as far back as 3000 B.C. Leonardo Di Vinci developed a rotary drilling system that resembles the technology of today in 1500. Despite these predecessors, rotary drills did not become popular or widespread until the early 1900s.
Although the basic concept of rotary drilling is simple, modern rigs have complex mechanics. The rotary drilling rig's primary movers are the pieces of equipment that supply the power for the whole rig. The power for the first drill rigs was provided by steam engines. After World War II, diesel and gas engines were the norm. While diesel engines are still the most common power source for rotary rigs today, there have been other engines in use. This is more true in the oil and natural gas sector than in the water-well sector. Commonly, natural gas and gasoline engines are used. Natural gas- or gas-powered reciprocating turbines are also used to generate electricity on-site. The electricity generated is used to power a rig. These prime movers provide energy for the rotary equipment, hoisting equipment, and the circulating gear. Larger rigs may also use the energy to supply water, lighting, and compression needs that are not directly related to drilling.
Hoisting Equipment. The hoisting equipment is the equipment that raises and lowers any other equipment in or out of the well. The derrick is the most prominent part of hoisting equipment. It supports the cables (drilling line) and pulleys(drawworks), which are used to lower or raise equipment in the well. In rotary drilling, for example, wells are constructed with long strings made of drill pipe that extend from the surface to the drill bit. The whole drill bit must be lifted to the surface if it needs to be replaced due to wear or damage to the subsurface rocks. To raise all this equipment to the surface, the hoisting equipment can be used. The drill bit can then be replaced and the entire drill pipe chain is then lowered into the well. A drill bit's height can often be used to determine the depth of the well.