�?�?t ε l ρ l v l + �?�?ε l ρ l v l v l = ε l �?�?τ l + ε l ρ l g �?ε l �?p �?β v l �?v s The paper will include the following principal matters: Deep nicely drilling technologies are of crucial relevance while in the drilling marketplace. In this method, the drilling fluid (drilling mud) is made use of to take