A method and apparatus for monitoring stress cage material concentrations in a circulating drilling fluid

摘要

An apparatus 1 for determining concentrations of stress cage materials in drilling fluid comprises wet sifting devices 2 dressed with one, two, three, four or five single-layered square mesh screen panels, positive displacement pumps 3 with a stroke counters for drawing a fluid sample into the apparatus and containment vessels 4 to collect discharged stress cage materials. The screen panels may comprise pre-tensioned mesh with an incorporated anti-blinding system. The wet sifting devices preferably generate a circular, horizontal and spiral pattern of travel to discharge any oversized fraction retained by the mesh screen. A method for the monitoring of stress cage materials in a circulating drilling fluid comprises pumping a representative sample of drilling fluid to the apparatus of the invention and weighing the stress cage particles discarded by the wet sifting devices.