Abstract: A continuous multi-component slurrying process at an oil or gas well comprises flowing at least three separate streams of different essential materials directly into a predetermined mixing unit at the oil or gas well, wherein each of the essential materials is required to obtain a predetermined defining characteristic of the slurry.

Abstract: A continuous multi-component slurrying process at an oil or gas well comprises flowing at least three separate streams of different essential materials directly into a predetermined mixing unit at the oil or gas well, wherein each of the essential materials is required to obtain a predetermined defining characteristic of the slurry.

Abstract: A method of controlling a continuous multi-component slurrying process at an oil or gas well comprises continuously flowing substances for creating a slurry in response to a slurry flow rate factor and continuously flowing another substance for the slurry in response to a flow rate of at least a predetermined one of the other substances or the slurry itself. The method can include density control, slurry (tub) level control, and a combination of such controls. The method can operate in either closed loop or open loop manner, and control can be effected with either of two types of control signals depending on whether the controlled device is an integrating or non-integrating type. The method can also provide for bumpless transition between manual and automatic control.

Abstract: A process control system includes a remote control computer connected by two pairs of electrical conductors to a local control computer and a monitor computer. The remote control computer provides a set point from entered control information, the monitor computer provides real time information about an operating characteristic of the process, and the local control computer receives feedback information from a characteristic of the process which is controlled by a control signal provided by the local control computer in response to the set point, the real time information and the feedback information. The monitor computer also provides information about monitored characteristics to the remote control computer. The real time information provided by the monitor computer to the local control computer is transmitted separately from the two pairs of electrical conductors.

Abstract: A process control system includes a remote control computer located remotely from where the process is to be performed, and the system includes a monitor computer and a local control computer both located where the process is to be performed. The monitor computer and the local control computer are connected to the remote control computer by a common cable including at most two communication channels, each defined in a preferred embodiment by a respective pair of electrical conductors.

Abstract: A process control system for mixing a proppant with a fluid includes a remote control computer located remotely from where the process is to be performed, and a monitor computer and a local control computer both located where the process is to be performed. An LAN cable connects the remote control computer to the monitor and local control computers. The desired concentration value of the proppant in the fluid is entered into the remote control computer. The monitor computer sends measured values to the local control computer which generates a control signal to a sand screw to provide the desired concentration value.

Abstract: A data monitoring system includes a display unit for communicating with an operation that has characteristics which are to be monitored, a recording unit located remotely from the environment of the monitored operation, and a local area network interconnect circuit for connecting the display and recording units. The local area network circuit allows multiple display units to be connected to a single pair of electrical conductors. Each display unit has at least one dual microcomputer configuration interconnected by a shared dual port random access memory. A third microcomputer is located in the recording unit for communicating over the local area network circuit with one of the microcomputers in the display unit.

Abstract: A data acquisition apparatus includes two microcomputers interconnected by a shared dual access digital storage device. One microcomputer obtains the data related to the monitored condition, stores it in the digital storage device, and modifies a status word which is monitored by the other microcomputer. When the other microcomputer detects a change in the status word, it takes the data from the shared digital memory and moves it into its own memory for subsequent use or transfer. The data acquisition apparatus also includes, in a preferred embodiment, analog switches and a digital to analog converter by which external analog devices can be controlled to change the monitored operation.

Abstract: A self-contained portable unit for producing a mixture of substances in response to two separate flows includes a portable trailer upon which a holding tank is mounted. Various additive channels are maintained on the trailer for introducing additives, at selectable concentrations or rates, into a first flow which occurs through an inlet conduit connected to an input of the holding tank. Connected to an output of the holding tank is an outlet conduit to which an external blender device can be connected. The trailer has additional additive channels contained thereon for introducing further additives, at selectable concentrations or rates, into a second flow between the holding tank and the external device. Control of the additives is maintained by a microcomputer-based controller or a manual, back-up controller, whichever is switchably selected for each additive channel.

Abstract: A portable apparatus for controlling the production of a mixture of a fluid and a plurality of additives utilizes a unified control panel having all of the necessary controls compactly contained in a single housing for providing both automatic and manual control of each of the additive channels through which the additives are mixed with the primary fluid. The control of each additive channel is achieved through a software controlled algorithm by which errors are only incrementally, rather than totally, applied to prior drive signals at any one time.

Abstract: An apparatus for controlling the metering of additives which are to be blended with a primary substance includes an element which determines how much additive is being discharged from an additive storage container. This element includes a weight detecting device which detects a first portion of the additive contained in a metering container and includes another weight detecting device for detecting the weight of a second portion of the additive contained in an inventory container which feeds the additive into the metering container. This element also includes a volumetric flow rate monitoring device for monitoring the flow rate of a liquid additive. Each of these detecting and monitoring devices generates respective electrical signals proportional to the respective monitored conditions. The apparatus also includes an element for sensing how much of the primary substance is being discharged from a primary substance container.

Abstract: A transportable frame includes a plurality of liquid material storage tanks and dry material storage bins mounted thereon. There are smaller liquid material storage tanks and larger liquid material storage tanks. The metering system for the larger liquid material storage tanks has a flow rate range varying from a low end to a high end. The metering system for the smaller liquid material storage tanks has a second flow rate range varying from a low end to a high end. The low end of the second range is lower than the low end of the first range, and the high end of the second range is between the low and high ends of the first range. There are also larger and smaller dry material storage bins with similarly sized metering systems for the dry material storage bins. The dry material storage bins are partially supported from the transportable frame by load cells which are mounted on extendable hydraulic cylinders.