Most of the global energy requirements are met by the natural oil and gas reserves present deep inside the earth. Over a period of several decades, man has made significant advances in the discovery, drilling and extraction of oil. It is very interesting to study and understand the process of drilling oil wells, extracting oil from underground reserves, and refine oil for various industrial and commercial purposes. This article is helpful for those job aspirants looking for offshore oil rigging jobs as it throws light on the process of drilling oil wells.

Locating Oil Reserves

The first step is for specialized geologist to identify the locations of oil reserves.  The geologists take seismic surveys using a seismograph.  They plant and explode underground charges in a controlled environment. These explosions create sound waves that are mapped by the seismograph.  By studying these waves, the geologists can draw a map of geological structures in the surrounding areas. These maps help spot oil reserves present far beneath the earth’s surface. 


After the detection of oil reserves, the next step is to erect a drilling rig on the earth’s surface that will eventually drill to the oil reserves below. A 5 and 36-inch wide hole is made through the earth’s surface to reach the oil reservoir. The drilling of the ground is aided by the weight of the drill piping over it. This drill piping is also used to pump in a drilling fluid, also termed as "mud",  to get rid of the rock debris that accumulates due to the drilling mechanism. The “mud” consist of plain water, water with air bubbles or polymers. When mud is pumped into the hole, it gets mixed up with the rock debris making it easy to suck this out of the oil rig. 


After the drilling process, the next step is the casing. A casing has to be set up  the length of the bored hole to prevent any leakage or wastage of precious oil reserves. Knowledge of the role of casing in drilling of oil wells is necessary for people looking for jobs in oil rigs. Casing can be done simply by installing a metal pipe down to the bottom of the hole. Oil rigs make use of concrete casing along with metal pipes for the interior lining to maintain and secure the flow of oil. Unstable oil wells or those with pressure problems use complicated casings that include multiple widths of concrete and metal pipe casings. These casings are designed to become narrower as the well gets deeper.

Perforations At The Bottom Of Bore Hole 

The final step in the process of drilling oil wells is to make holes or perforations around the base of the bore hole. Making these perforations will make way for the oil to ooze out of the surrounding rock formations and be directed into the oil well. When tapping into a newly discovered oil well, the underground pressure will be sufficient to bring the oil to the surface. This is largely due to the pile up of high pressure in the oil reserves below. 

This article will be helpful for job aspirants who wish to land jobs in oil rigs to understand the process of drilling oil wells. The article outlines the various steps involved in the process of drilling oil wells.