1. n. [Drilling Fluids]
A mud sample taken after it has passed from the flowline and through the shale shaker screens to remove large cuttings. The out sample is also called the shale shaker sample. This mud has experienced the downhole pressures, temperatures and contamination that cause degradation. It is evaluated for needed treatments and compared, on a lagged time basis, with the corresponding "in" or mud-in sample.