�?�?t ρ l k + �?�?x i ρ l k v l = �?�?x j μ + μ t σ k �?k �?x j + G k �?ρ l ε �?Y M Although desired, stopping lost circulation completely is just not always doable or needed. Controlled losses allow drilling to carry on when retaining the wellbore whole, blocking an influx of gas or fluid in to the wellbore, often