Patent ID: 7947628

Claim:
A method to control drilling fluid properties, the method comprising; circulating a drilling fluid through a wellbore to form a suspension of drilled solids in the drilling fluid; passing the suspension through one shale shaker to form a particulate fraction comprising at least a portion of the drilled solids and an effluent fraction that comprises the drilling fluid; said shale shaker comprising screens; each of said screens having a minimum particle cut screen size between about 10 microns and about 100 microns; wherein the particulate fraction comprises particulates having a particle size of 100 microns or greater; wherein the effluent comprises a micronized weighting agent having a particle size d 90 of 10 microns or less; and wherein said screens having a minimum particle cut screen size between about 10 microns and about 100 microns are the only screens used in the method.