�?�?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 protect the following major subject areas: Deep well drilling technologies are of significant value inside the drilling field. In this process, the drilling fluid (drilling mud) is made use of to take care of