The oil industry has come a long way since the Drake Well was drilled in the United States in 1859. In the early days of the industry, exploration could focus on areas where oil simply bubbled to the grounds, and producers could rely on the pressure in fields to propel oil through a well.
While conventional oil is certainly not dead, the oil industry has developed innovations to improve efficiency, extend the life of depleted fields and access reserves that were previously uneconomical. Here are two innovations that have changed the nature of well drilling:
1. Measurement-while-drilling (MWD) technology
Prior to the 1980s and the development of MWD, it was difficult for drill operators to gain information about what was happening as a hole was being drilled. MWD changed this by providing the operator with real-time information about the drilling status, as well as data about temperature, pressure, gamma rays, and rock formation density and magnetic resonance. All this helps operators to improve efficiency and minimise tool failures. It also offers the option to steer the well in a different direction.
A particular challenge to this technology was how to transmit the data to the surface, seeing as stringing a cable from the surface to the drill bit is simply not practical. An innovative solution to this problem was found in the form of mud pulse telemetry, where the mud slurry that is used to carry debris to the surface is implemented as an acoustic channel over which to transmit binary data.
2. Horizontal drilling
As mentioned above, MWD technology enabled operators to steer the direction of the well. Combined with the development of steerable motor assemblies, this opened up the possibility of drilling horizontal wells in an affordable manner.
This primarily comes into play when a reservoir is spread out horizontally, enough so that drilling a vertical well would not provide efficient oil extraction. Horizontal drilling, of course starts by drilling vertically down until it reaches what’s known as the kick-off point before the reservoir. The drill then changes direction and proceeds horizontally into and through the reservoir.
Horizontal drilling is not just about well efficiency, though. It also enables reservoirs below environmentally sensitive land to be exploited from a safe location. ExxonMobil, which makes hydraulic oils like Mobil DTE 24, has taken this concept further by drilling up to 12km under the Sea of Okhotsk, making some offshore fields accessible from dry land.