Drilling mud additives and types of drilling mud (drilling mud or drilling fluid) – Reservoir drilling operations cover about 80% of the total cost of a well and can be called the main operation. Drilling oil and gas wells is a difficult, accurate operation, requires a lot of costly studies, among which drilling fluid is a very important material due to its multiple applications. Drilling mud is a fluid that is sent into the well with a drill by a pump and leaves the well after performing the expected work, but this operation is done in rotation. A typical drilling fluid can be a mixture of water and soil. It is a clay that is used to lift chips from drilling operations. But as mentioned, due to the different functions that this fluid must have, other additives are added to it.