Abstract: A method for servicing a well bore comprises connecting a mixing system to the well bore, controlling the mixing system to produce a material mixture with approximately a desired density, and controlling the mixing system to provide the material mixture to the well bore at approximately a desired volumetric flow rate to service the well bore, wherein the controlling to produce approximately a desired density is independent from the controlling to provide approximately a desired volumetric flow rate.

Abstract: A control system for mixing at least two materials in a physical system having two or more tanks comprises at least two actuators, each actuator being operable to introduce a material into a first tank to form a first mixture, the first mixture flowing into a second tank to form a second mixture and a controller operable, based on a commanded input, to control the at least two actuators to obtain a density of either the first mixture or the second mixture and a volume flow rate of the second mixture out of the second tank, wherein the density is controlled independently from the volume flow rate.

Abstract: Methods, control systems, and information handling systems for controlling at least two actuators are provided. An internal control system sends an input received from the main control system to a first actuator and diverts a portion of the input to a second actuator when an input constraint of the first actuator is reached. The actuators may be throttle valves for heating a hydraulic line. The internal control system includes a cutoff rerouter for implementing the sending and the diverting of the input and an adaptive cutoff controller, e.g., an integral controller, for determining the input constraint of the first actuator. The information handling systems include a determination logic for determining if an input received from the main control system is greater than an input constraint of the first actuator and a diverting logic for diverting a portion of the input to a second actuator when the input is greater.

Abstract: Methods for controlling at least two actuators are provided. An internal control system sends an input received from the main control system to a first actuator and diverts a portion of the input to a second actuator when an input constraint of the first actuator is reached. The actuators may be throttle valves for heating a hydraulic line. The internal control system includes a cutoff rerouter for implementing the sending and the diverting of the input and an adaptive cutoff controller, e.g., an integral controller, for determining the input constraint of the first actuator.

Abstract: Systems and methods are provided for estimating the height of a fluid contained in a mixing tank. A dynamic control device which operates as an external observer is used for controlling and monitoring the estimation. This estimate of the height is then compared to the measured fluid height in the mixing tank to obtain an estimation of the height error. The mixing tank has one or more input volumetric rates which are known along with the output volumetric rates. This height error is used to drive the estimation to the nominal height of the mixing tank through the use of a Proportional Integral PI type controller. By setting the PI gains, the noise and oscillations of the mixing tank can be removed from the height estimation while tracking the nominal value of the height. The methods and the systems can also be implemented for estimating the volume or quantity of fluid contained in a mixing tank.

Abstract: Systems and methods are disclosed for controlling a viscosity of a fluid. The control system includes a controller controlling an input to an actuator and an observer estimating the viscosity of the fluid. The controller includes an input, and the actuator is capable of controlling a viscosity of a fluid by delivering a gelling agent to the fluid. The observer and the controller are coupled together. The observer may be used to determine the viscosity at the current time from a sensor and filter combination that lags the actual viscosity value. The estimated sensor and filter output may be then compared to the sensor and filter output to make corrections to the estimate of the viscosity of the current time.

Abstract: Systems, methods and devices are disclosed for controlling fluids parameters in a heat exchanger. In one embodiment, an apparatus for controlling a heat exchanger system may include a first controller and a second controller. Each controller may control an actuator associated with a parameter of the heat exchanger system. Each controller may include a feedback gain and a cross coupling gain. The cross coupling gain may cross couple the system inputs to the actuators. The parameters are the temperature and the mass flow rate. The heat exchanges fluids are the heat transfer fluid and the controlled fluid.