Oil and gas exploration makes use of several types of drilling methods and platforms based on the type of formations, geographic location, soil type and the like. Here are five of the most common drilling methods used in extracting oil and gas from beneath the earth:
Percussion drilling is an oft-used manual drilling technique in which a hammering bit is attached to a long cable that is then lowered into a wide open hole. The technique is also known as cable drilling, wherein the driller uses a tripod to support the tools. By going back and forth with the bit, the action loosens the soil in the borehole, which is then extracted with the help of a bailer. At intervals, the bit is removed while the cuttings are suspended in water, which is then removed by pumping to the surface. A steel casing helps prevent the hole from collapsing down temporarily and also to protect the hole against contamination of groundwater. The temporary setting is to be removed after a permanent screen and casing are installed.