The weight of drilling mud is one of its important features. In general, drilling mud has a variety of properties and making changes in each of them can lead to changes in flower properties and applications. In the drilling industry, especially the drilling of gas and oil wells, the issue of drilling mud weight is of great importance. This feature can play an important role in the control of underground pressure and drilling transmitters. In this article we will go into more details on the role of mud weight in drilling operations.
Control of underground pressures
One of the important tasks of drilling mud is to control underground pressures. This pressure control is also directly related to the weight of drilling mud. In fact, the mud controls these pressures with the help of its weight. The weight of the mud inside the drilling well creates hydrostatic pressure.
Therefore, by lowering or increasing its weight, it is possible to have precise control over ground pressures. Adjusting underground pressures prevents the mud from flowing into the structure of the well.
what is the Formation pressure ?
Formation pressure is the pressure that tries to return to the initial state (before drilling). In scientific terms, the resultant force is zero at equilibrium. That is to say, the amount of force applied is equal to each dimension and has made the equilibrium. Now if this equilibrium is disturbed in any way; at points of equilibrium there is a tendency to return to the original state and create a zero result. In the drilling industry, this tendency is called “ordinary pressure gradient.” And this slope is the pressure that causes the walls of the well to crumble.
Another type of pressure inside the well is fluid pressure. Any fluid in the well can produce pressure. Water, oil and gas are internal pressures in this regard. This model of pressure applied to the well is called Abnormal Pressure (Abnormal).
Finally, in these situations, three scenarios may occur:
- The mud pressure is higher than the formation pressure.
- The mud pressure is lower than the formation pressure.
- The mud pressure is equal to the formation pressure.
Transferring drilling chips to ground level
One of the most important tasks of drilling mud is to transfer drill chips to the ground and the weight of drilling mud plays an important role in this regard. In simple terms, when the chips are pulled out of the well against the gravity pull, it creates a gravity that can be offset by changing the weight of the drilling mud and adjusting the chip’s outflow velocity.
In this context, in order to move the drill chips out, it is important that the speed of the mud rise must be greater than its rate of fall. There is a rule in the science of physics called the Law of Submerged Substances which causes anybody submerged in any fluid to receive a force known as a floating force. This force enters from the bottom upwards in the opposite direction of the Earth’s gravity. As a result, controlling the amount of this force to counteract the gravity will force the chip out of the well in a controlled manner.
As the weight of the flower increases, the ratio of solid to liquid particles increases. This feature increases the buoyancy of the drilling mud and increases its carrying capacity.
If you want to know more about the drilling mud and its features, read the article “Investigation of types of drilling mud and their properties” in Nikan West Gilsonite blog.