Oil drilling not just meets the fuel demands of the country but also is a profitable business. Many techniques are used to bring out the oil to the earth's surface. You can also know more about oil well abandonment online.
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The conventional method was the percussion method where the earth is penetrated using a heavy tool and the oil is pumped out through the hole. The disadvantage of this method is that it is a slow process that has to be stopped periodically.
However, modern directional drilling technologies allow horizontal drilling or sub-horizontal wells. These wells have more surface area than vertical wells and hence ensure higher productivity.
The latest oil drilling techniques have made it possible to reach out to oil pockets that are many miles away from the drilling site. This also helps to tap most of the oil reserves from even those locations that are populated or environmentally sensitive.
In most of the wells, the natural pressure of the subsurface reservoir is more than enough for the oil to flow out to the surface. However, in the case of low permeability oil reservoirs, very often artificial lift methods including downhole pumps and gas lifts are also used to drive up the oil or the natural gas.
The production stage is the most crucial phase in oil drilling. In this phase, the rigs used to drill the well are moved to the wellbore and fitted with valves that control pressure and regulate flow. The outlet valve is connected to a distribution network of pipelines and tanks that ferry the crude oil to refineries or oil export terminals.