�?�?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 decrease in annular return circulation will lead to the movement velocity of drilling https://lukaspfrky.ageeksblog.com/40033040/the-fact-about-loss-circulation-control-that-no-one-is-suggesting