Volumetric control for proppant concentration in hydraulic fracturing
AssigneeHalliburton Energy Services, Inc.
InventorsMehdi Mazrooee, Michael Linley Fripp
Life of this patent
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Abstract
Methods and systems for controlling proppant concentration in a hydraulic fracturing slurry include measuring volumetric flow rates of fracturing fluid input to a blender and hydraulic fracturing slurry output from the blender, using these measured values to calculate a volumetric flow rate of proppant input, a slurry density and/or a slurry volume fraction, adjusting first and second valves to control rates of fluid and proppant delivery to the blender and re-measuring the volumetric flow rates and recalculating until target values of volumetric flow rate of proppant input, slurry density and/or slurry volume fraction are achieved.
Claims20
A method of controlling proppant concentration in a hydraulic fracturing slurry, comprising:
- a) transmitting to a non-transient computer readable memory of a blender control unit, target input values of a slurry density (ρsl-target), a slurry volumetric flow rate ({dot over (V)}sl-target), and inputs of a known density of a fracturing fluid (ρfl) and known density of a proppant (ρpr);
- b) sending from a transmitter of the blender control unit, a command signal to actuate a first valve to deliver the fracturing fluid to a blender;
- c) sending from the transmitter of the blender control unit, a second command signal to actuate a second valve to deliver the proppant to the blender at a non-zero proppant mass flow rate ({dot over (m)}pr);
- d) measuring, using a first volume flow rate sensor, a volumetric flow rate ({dot over (V)}fl) of the fracturing fluid input to the blender and transmitting a signal corresponding to the measured {dot over (V)}fl to a signal receiver of the blender control unit;
- e) measuring, using a second volume flow rate sensor, a volumetric flow rate ({dot over (V)}sl) of the hydraulic fracturing slurry output from the blender and transmitting a signal corresponding to the measured Vsl to the signal receiver of the blender control unit;
- f) executing computer readable instructions, stored in the memory of the blender control unit to calculate, in a central processing unit of the blender control unit:
- a volumetric flow rate of proppant input ({dot over (V)}pr) to the blender according to the formula:
- {dot over (V)}pr=({dot over (V)}sl−{dot over (V)}fl), and,
- a slurry density (ρsl) according to the formula:
- ρsl=(({dot over (V)}fl⋅ρfl)+({dot over (V)}pr⋅ρpr))/{dot over (V)}sl;
- g) determining, in the central processing unit, a difference (Δρsl) between the ρsl-target and the ρsl, and, a difference (Δ{dot over (V)}sl) between the {dot over (V)}sl-target and the {dot over (V)}sl;
- and then
- h) if the Δρsl is not less than an acceptable slurry density margin of error (ER-ρsl) or the Δ{dot over (V)}sl is not less than an acceptable slurry volumetric flow rate margin of error (ER-{dot over (V)}sl), the central processing unit sends instructions to cause the command signal to further actuate the first valve to incrementally change the {dot over (V)}fl or sends instructions to cause the second command signal to further actuate the second valve to incrementally change the {dot over (m)}pr, and then the central processing unit send instructions to cause steps (d)-(h) to be repeated, and
- i) if the Δρsl is less than ER-ρsl and the Δ{dot over (V)}sl is less than ER-{dot over (V)}sl, then the central processing unit sends an output signal to a display unit of the blender control unit to indicate that the target input values have been achieved.
A method of controlling proppant concentration in a hydraulic fracturing slurry, comprising:
- a) transmitting to a non-transient computer readable memory of a blender control unit, a target slurry volumetric flow rate ({dot over (V)}sl-target), a target input value of a slurry volume fraction (Cs-target), and inputs of a known density of a fracturing fluid (ρfl) and known density of a proppant (ρpr);
- b) sending from a transmitter of the blender control unit, a command signal to actuate a first valve to deliver the fracturing fluid to a blender;
- c) sending from the transmitter of the blender control unit, a second command signal to actuate a second valve to deliver the proppant to the blender at a non-zero proppant mass flow rate ({dot over (m)}pr);
- d) measuring, using a first volume flow rate sensor, a volumetric flow rate ({dot over (V)}fl) of the fracturing fluid input to the blender and transmitting a signal corresponding to the measured {dot over (V)}fl to a signal receiver of the blender control unit;
- e) measuring, using a second volume flow rate sensor, a volumetric flow rate ({dot over (V)}sl) of the hydraulic fracturing slurry output from the blender and transmitting a signal corresponding to the measured {dot over (V)}sl to the signal receiver of the blender control unit;
- f) executing computer readable instructions, stored in the memory of the blender control unit to calculate, in a central processing unit of the blender control unit a volumetric flow rate of proppant input ({dot over (V)}pr) to the blender according to the formula:
- {dot over (V)}pr=({dot over (V)}sl−{dot over (V)}fl), and, a slurry volume fraction according to the formula:
- Cs=({dot over (V)}sl−{dot over (V)}fl)/{dot over (V)}sl;
- g) determining, in the central processing unit, a difference (Δ{dot over (V)}sl) between the {dot over (V)}sl-target and the {dot over (V)}sl, and, a difference (ΔCs) between the Cs-target and the Cs;
- and then
- h) if the Δ{dot over (V)}sl is not less than an acceptable slurry volumetric flow rate margin of error (ER-{dot over (V)}sl) or the ΔCs is not less than an acceptable slurry volume fraction margin of error (ER-Cs), then the central processing unit sends instructions to cause the command signal to further actuate the first valve to incrementally change the {dot over (V)}fl or to cause the second command signal to further actuate the second valve to incrementally change the {dot over (m)}pr, and then the central processing unit repeats steps (d)-(h), and
- i) if the Δ{dot over (V)}sl is less than ER-{dot over (V)}sl and the ΔCs is less than the ER-Cs, then the central processing unit sends an output signal to a display unit of the blender control unit to indicate that the target input values have been achieved.
A blending system for controlling proppant concentration of a hydraulic fracturing slurry, comprising:
- blender control unit, the blender control unit including:
- an input device configured accept target input values of a slurry density (ρsl-target) a slurry volumetric flow rate ({dot over (V)}sl-target), or, a slurry volume fraction (Cs-target), and inputs of a known density of a fracturing fluid (ρfl) and known density of a proppant (ρpr);
- a command signal transmitter configured to send a command signal to actuate a first valve to deliver the fracturing fluid to a blender and send a second command signal to actuate a second valve to deliver the proppant to the blender at a non-zero proppant mass flow rate ({dot over (m)}pr);
- a signal receiver configured to a receive a signal corresponding to a measured volumetric flow rate ({dot over (V)}fl) of the fracturing fluid input to the blender and receive a signal corresponding to a measured volumetric flow rate ({dot over (V)}sl) of the hydraulic fracturing slurry output from the blender;
- a non-transient computer readable memory configured to store the target values of ρsl-target, {dot over (V)}sl-target, or Cs-target and the inputs of the ρfl and the ρpr and to store computer readable instructions to calculate a volumetric flow rate of proppant input ({dot over (V)}pr) to the blender according to the formula:
- {dot over (V)}pr=({dot over (V)}sl−{dot over (V)}fl), to calculate a slurry density (ρsl) according to the formula:
- ρsl=(({dot over (V)}fl⋅ρfl)+({dot over (V)}pr⋅ρpr))/{dot over (V)}sl, and to calculate a slurry volume fraction according to the formula:
- Cs=({dot over (V)}sl−{dot over (V)}fl)/{dot over (V)}sl;
- and
- a central processing unit configured to:
- read the computer readable instructions and to calculate:
- the {dot over (V)}pr and the ρsl, and to determine a difference (Δ{dot over (V)}sl) between the {dot over (V)}sl-target and the {dot over (V)}sl and a difference (Δρsl) between the ρsl-target and the ρsl, or, to calculate:
- the {dot over (V)}pr and the Cs and to determine a difference (Δ{dot over (V)}sl) between the {dot over (V)}sl-target and the {dot over (V)}sl and a difference (ΔCs) between the Cs-target and the Cs, and then:
- if the Δρsl is not less than an acceptable slurry density margin of error (ER-ρsl) or the Δ{dot over (V)}sl is not less than an acceptable slurry volumetric flow rate margin of error (ER-{dot over (V)}sl), then send instructions to cause the command signal to further actuate the first valve to incrementally change the {dot over (V)}fl or to cause the second command signal to further actuate the second valve to incrementally change the {dot over (m)}pr and if the Δρsl is less than ER-ρsl and the Δ{dot over (V)}sl is less than ER-{dot over (V)}sl, then send an output signal to a display unit of the blender control unit to indicate that the target input values have been achieved, or,
- if the Δ{dot over (V)}sl is not less than an acceptable slurry volumetric flow rate margin of error (ER-{dot over (V)}sl) or the ΔCs is not less than an acceptable slurry density margin of error (ER-Cs), then send instructions to cause the command signal to further actuate the first valve to incrementally change the {dot over (V)}fl or to cause the second command signal to further actuate the second valve to incrementally change the {dot over (m)}pr and if the Δ{dot over (V)}sl is less than ER-{dot over (V)}sl and the ΔCs is less than the ER-Cs, then the central processing unit sends an output signal to a display unit of the blender control unit to indicate that the target input values have been achieved.
Dependencies are inferred from the claim text.