�?�?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 Considering that more than one variety of drilling fluid loss can current occasionally, it is necessary to ascertain the loss varieties and evaluate proportion of each and every loss form In order to find out the major and