�?�?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 If the amount of fluid in the wellbore drops on account of lost circulation https://vertechs21.weebly.com/blog/revolutionizing-the-depths-how-vertechs-is-redefining-drilling-fluids-for-safer-smarter-oilfield-operations