Shale Shaker Selection
Shaker screen or you can say shale shaker screen too, is a type of mechanical screen, aim for take solids out or separate solids from drilling fluid (mud). Usually it’s made by stainless steel, polyurethane or composite frame. It’s a spare part of shale shaker and combined shaker frame by stainless screw and wedge block.
This exercise involves the cost benefit of increasing solids removal equipment efficiency to 80% for the 4%vol drilled-solids concentration: With 80% removal efficiency and 1143 bbl of drilled solids reporting to the surface, 914 bbl would be discarded and 229 bbl returned to the pits. The drilling fluid needed to dilute the 229 bbl to 4%vol would require adding (229 bbl / 0.04), or 5725 bbl of new drilling fluid. This 5725 bbl would consist of 229 bbl of drilled solids and 5496 bbl of clean drilling fluid.
Drilling fluids normally contain two categories of solids: (1) commercial clays and drilled solids, both low gravity, with specific gravities (SGs) of about 2.6, and (2) weighting agents, usually barite, with an assumed SG of 4.2. If all of the solids particles were of the same size, decanter centrifuges could be used to separate the weighting agent from the low-gravity solids, because the barite particles, due to their higher SG, would be heavier. Drilling fluids, of course, are not slurries of particles of equal size. Weighted drilling fluids always contain solids of both categories, ranging from colloidal particles too fine to settle, even in pure water, to particles 70 microns () in size and larger. Consequently, the centrifuge cannot separate barite from low-gravity solids. What it does, when operated properly, is separate larger barite particles from smaller ones and larger low-gravity-solids particles from smaller ones. Failure to recognize this very important fact frequently leads to the misuse of centrifuges.