Drilling Fluids have been used ever since the search for oil began and are in use even today as drilling operations go deeper searching for different resources. One must note though, that not all drilling operations today are conducted for finding energy resources deep within the earth’s crust. Drilling operations have also been widely conducted around the world for environmental investigations as well.
Drilling fluids play a dual role in drilling rigs especially for the bigger ones that have to dig deeper for resources (such as oil). They get two jobs done; depending on the equipment used, drilling fluids help in carrying the excavated rock to the surface and also if in a liquid state help cool the drill increasing its lifespan.
Another very important function of drilling fluids is that they help maintain pressure within wellbores preventing them from collapsing. This is why they come in different densities and need to be selected carefully depending on the depth and the material that the drill will be encountering at various depths.
There are different types of drilling fluids available and are used depending on the drill, depth and the hardness of the bed rock.
Air: Depending on the mechanism and drill used, air systems channel air through the drill or the drill string driving the drill and delivering dust back to the surface.
Air/Polymer: This system is similar to the previous system but with the addition of a specially formulated polymer such as a foaming agent. The agent is added to the mixture of water and air, helping deliver the excavated material to the surface.
Water: Sometimes in smaller operations or depending on the resources and area being drilled, water is also used to deliver the sludge to the surface. This apart from delivering the sludge also helps cool down the drill.
Mud systems: Water based mud or oil based mud systems are often used if the excavated materials also have value. In this process complex equipment is used to filter and process the sludge that emerges as a by-product of the drilling process.