Abstract: An improved rotational viscometer for testing drilling muds is disclosed. In a preferred and illustrated embodiment, a rotatable tubular sleeve is driven by a pulsed stepper motor. The drilling mud couples to a bob of cylindrical shape supported on a shaft. The sleeve is rotated or torqued, applying rotation to the shaft which is monitored by an optical encoder. The stepper motor is driven for a programmable sequence of specific intervals at specific speeds, and the mud coupled rotation at the encoder shaft is observed. The data obtained is scaled to provide an indication of viscosity and other measurements of the drilling mud indicated by an output LED display or other display type as desired. The mud is tested by a specified sequence of test procedures sanctioned by the American Petroleum Institute.

Abstract: An improved rotational viscometer is provided, having a base, a housing, and one and only one adjustable support leg supporting the housing from the base. The support leg provides for adjustment of the length of the leg and provides for alignment of the housing relative to the base. A rotatable tubular sleeve extends downwardly from the housing, and an electric motor is provided in the housing for driving the rotatable sleeve. The electric motor is connected to the rotatable sleeve by a toothed pulley and belt assembly. A cylindrical non-metallic bob is concentrically positioned within the tubular sleeve and is attached to the lower end of a bob shaft. The upper end of the bob shaft has an indicator dial attached thereto and is connected to the housing by a torsional string.

Abstract: An apparatus is presented which simulates the circulation system through which a fluid is circulated in an oil well. The apparatus includes manually adjustable control means which simulate the circulation system controls used in the circulation of fluid through the oil well. The controls are interfaced with, and drive a digital programmable calculator which calculates the pressure and volume of fluid at a plurality of points in the oil well. The calculator in turn is interfaced with display means which simulate the circulation system instrumentation during the simulated circulation process. The apparatus additionally includes means for calculating a formation pressure which is randomly higher than the fluid pressure at the depth of the formation. Responsive to this increased formation pressure, the apparatus simulates the invasion of formation fluid into the well bore and simulates the reaction of the circulation system as the formation fluid is circulated to the surface.