�?�?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 consequences of lost circulation can be as small as being the loss of some bucks of drilling fluid, or as disastrous being a blowout and loss of lifetime, so shut checking of tanks, pits, and stream with the nicely, to