Abstract: A method and apparatus for determining the effectiveness and reaction time of a breaker fluid in breaking a filter cake on the wall of a wellbore penetrating a subterranean formation is disclosed. The method comprises employing an apparatus, such as for example the apparatus of the invention with a filter medium and the capability of applying differential pressure or dynamic conditions to form a filter cake on the filter medium with drilling mud. Breaker fluid is then substituted for the drilling mud, preferably without damage to the filter cake. The quantity of breaker fluid passing across the filter medium under static conditions is monitored over time. An increase in the rate of fluid passing across or through the medium indicates break-up of the filter cake.

Abstract: A method of testing magnetorheological fluid comprises cycling the fluid at an elevated temperature, allowing the fluid to stand, performance testing the fluid, cycling the fluid at superimposed frequencies, and noting settling characteristics of the fluid.

Abstract: An in-line monitoring apparatus for monitoring particulate matter in a liquid stream includes an inlet and outlet for ingress and discharge of a liquid stream. An in-line particulate matter-sampling unit is arranged for accumulation of particulate matter suspending in the liquid flow between the inlet and outlet, including an apparatus for measuring particulate matter accumulation therein. Further, there is apparatus for separating particulate matter from the liquid stream and for providing the particulate matter to the in-line sampling unit and control apparatus for operating the in-line monitoring apparatus in a first and second operative mode.

Abstract: An improved method for measuring the chromatographic properties, such as excluded volume, of hydrophobic polymer substrates is disclosed. Use of 0.05-1 micron sized crosslinked ionically-charged polymer particles, especially emulsion-form or ground polymer particles, as a large-molecule probe, allows environmentally friendly aqueous-based solvent systems to be used as mobile phases to characterize hydrophobic polymer supports for use in analytical or preparative scale chromatographic applications. This method eliminates the use of non-polar organic solvents that is required when conventional non-polar large-molecule probes (such as polystyrene) are used to characterize chromatographic media.

Abstract: An apparatus for monitoring particulates in a liquid stream and the rate at which the particulates foul a filtering medium, generally a reverse osmosis membrane, to determine at what point in time the filtering medium should be cleaned or replaced. The apparatus includes a monitoring filter unit having a plurality of filter portions. The pressure drop across each filter portion, through which a sample of the feed stream is passed, is monitored. Fouling of a filter portion by accumulated particulate thereon causes an increase in the pressure drop across the filter unit. The increasing pressure drop is monitored as an indicator of the correlative or correspondent fouling of the main filtering medium to be protected. Different filter portions in the filter unit are successively used as each becomes fouled, allowing continuous monitoring for extended periods of time between filter media changes in monitoring filter unit.