Slug Weight Calculator

Usually the slug pit will determine the volume of slug that will be used so it comes in handy to know the weight required of the slug to keep the pipe above the bell nipple dry.

To determine the weight of the slug we first need to determine the length of pipe we need to keep dry. This is essentially the length of one stand of drill pipe. Once you have determined the length to keep dry, we can calculate the hydrostatic pressure necessary to "push" the mud below that length of pipe and thus the mud weight required in the slug.

We first need to calculate the drill pipe capacity, then the length of the slug in the pipe, then we calculate the hydrostatic pressure required to push the mud down the stand of drill pipe, and finally we calculate the weight of the slug.

Note that the general rule of thumb is to weight up the slug to 2ppg (0.24sg) above the mud weight in the hole.