Process control system using remote computer and local site control computers for mixing a proppant with a fluid

Claim 1

A system for controlling at a well site an apparatus, including at least one sand crew, for moving a proppant into a mixing container into which a fluid is flowed for obtaining a blend having a desired concentration of said proppant in said fluid, which blend is to be pumped into the well and which apparatus and mixing container are mounted on a trailer, said system comprising: a remote control computer spaced from the trailer, said remote control computer including means for entering information defining a desired concentration value of said proppant in said fluid; a monitor computer mounted on the trailer, for monitoring a flow rate of said fluid and for monitoring a density of said blend, said monitor computer being electrically connected to said remote computer such that said fluid flow rate and said blend density are received by said remote computer; at least one transducer disposed on said sand screw, said transducer for providing a feedback control signal based upon a quantity of proppant moved; a local control computer mounted on the trailer and electrically connected to said monitor computer, said remote control computer, and said transducer so that said local control computer receives said desired concentration value, said fluid flow rate, and said feedback control signal, said local control computer for providing a control signal to said sand screw based upon, and varying in accordance with, said fluid flow rate, said desired concentration value and said feedback control signal; interface means, mounted on the trailer, for connecting said local control computer to said transducer, for connecting said monitor computer to a flow meter which provides said fluid flow rate, and for connecting said monitor computer to a densimeter which provides said blend density; and a local area network cable connected between said remote control computer and both said monitor computer and said local control computer so that said fluid flow rate and said blend density are communicated therethrough from said monitor computer to said remote control computer and so that said desired concentration value is communicated therethrough from said remote control computer to said local control computer.

Claim 2

A system for controlling at a well site an apparatus, including at least one sand crew, for moving a proppant into a mixing container into which a fluid is flowed for obtaining a blend having a desired concentration of said proppant in said fluid, which blend is to be pumped into the well and which apparatus and mixing container are mounted on a trailer, said system comprising: a remote control computer spaced from the trailer, said remote control computer including means for entering information defining a desired concentration value of said proppant in said fluid; a monitor computer mounted on the trailer, for monitoring a flow rate of said fluid and for monitoring a density of said blend, said monitor computer being electrically connected to said remote computer such that said fluid flow rate and said blend density are received by said remote computer; at least one transducer disposed on said sand screw, said transducer for providing a feedback control signal based upon a quantity of proppant moved; a local control computer mounted on the trailer and electrically connected to said monitor computer, said remote control computer, and said transducer so that said local control computer receives said desired concentration value, said fluid flow rate, and said feedback control signal, said local control computer for providing a control signal to said sand screw based upon, and varying in accordance with, said fluid flow rate, said desired concentration value and said feedback control signal; interface means, mounted on the trailer, for connecting said local control computer to said transducer, for connecting said monitor computer to a flow meter which provides said fluid flow rate, and for connecting said monitor computer to a densimeter which provides said blend density; and a local area network cable connected between said remote control computer and both said monitor computer and said local control computer so that said fluid flow rate and said blend density are communicated therethrough from said monitor computer to said remote control computer and so that said desired concentration value is communicated therethrough from said remote control computer to said local control computer.