Hydraulic fracturing with modulating injection flow rate
A system for hydraulic fracturing includes a pump system fluidly coupled to a wellbore; and a controller configured to estimate a natural frequency of the wellbore based on a pressure wave response from the wellbore, and control the pump system to pump fluid into the wellbore at an oscillating flow rate based on the estimated natural frequency of the wellbore.
1 . A system for hydraulic fracturing, comprising:
a pump system fluidly coupled to a wellbore; and
a controller configured to:
estimate a natural frequency of the wellbore based on a pressure wave response from the wellbore;
generate a treatment schedule based on the estimated natural frequency of the wellbore, wherein the treatment schedule comprises a period of an oscillating flow rate, an amplitude of the oscillating flow rate and a duration of the oscillating flow rate, and
control the pump system to pump fluid into the wellbore at the oscillating flow rate according to the treatment schedule.
2 . The system of claim 1 , wherein the pump system comprises one or more electric pumps.
3 . The system of claim 1 , wherein the pump system comprises one or more diesel pumps.
4 . The system of claim 1 , wherein the controller is further configured to control the pump system to generate a pressure disturbance that reflects off of the wellbore to cause the pressure wave response from the wellbore.
5 . The system of claim 1 , wherein the treatment schedule further comprises a waveshape of the oscillating flow rate.
6 . The system of claim 1 , further comprising a power supply system electrically coupled to the pump system, wherein the controller is further configured to generate the treatment schedule based on a limitation of the power supply system.
7 . The system of claim 1 , further comprising a fluid supply system fluidly coupled to the pump system, wherein the controller is further configured to generate the treatment schedule based on a limitation of the fluid supply system.
8 . The system of claim 1 , wherein the controller is further configured to modulate the oscillating flow rate to sweep across the estimated natural frequency of the wellbore.
9 . The system of claim 1 , wherein the controller is further configured to re-estimate the natural frequency of the wellbore, and adjust a frequency of the oscillating flow rate based on the re-estimated natural frequency.
10 . The system of claim 1 , wherein the period is set such that a frequency of the oscillating flow rate is within 10% of the natural frequency of the wellbore or a harmonic of the natural frequency of the wellbore.
11 . A method for hydraulic fracturing, comprising:
estimating a natural frequency of a wellbore based on a pressure wave response from the wellbore;
controlling a pump system to pump fluid into the wellbore at an oscillating flow rate based on the estimated natural frequency of the wellbore,
re-estimating the natural frequency of the wellbore; and
adjusting a frequency of the oscillating flow rate based on the re-estimated natural frequency.
12 . The method of claim 11 , wherein the pressure wave response is caused by sweeping a frequency of the oscillating flow rate across the natural frequency of the wellbore.
13 . The method of claim 11 , wherein the controlling of the pump system further comprises setting the frequency of the oscillating flow rate within 10% of the natural frequency of the wellbore or a harmonic of the natural frequency of the wellbore.
14 . A system for hydraulic fracturing, comprising:
a first pump system fluidly coupled to a first wellbore;
a second pump system fluidly coupled to a second wellbore; and
a controller configured to estimate a natural frequency of the first wellbore based on a pressure wave response from the first wellbore or a pressure wave response from the second wellbore, control the first pump system to pump fluid into the first wellbore at a first oscillating flow rate based on the estimated natural frequency of the first wellbore, and control the second pump system to pump fluid into the second wellbore at a second oscillating flow rate based on the first oscillating flow rate or the pressure wave response from the second wellbore.
15 . The system of claim 14 , wherein the controller is further configured to control the second pump system to pump fluid into the second wellbore at the second oscillating flow rate based on an estimated natural frequency of the second wellbore.
16 . The system of claim 14 , wherein a frequency of the first oscillating flow rate is the same as a frequency of the second oscillating flow rate, the frequency of the first oscillating flow rate is a multiple of the frequency of the second oscillating flow rate, or the frequency of the second oscillating flow rate is a multiple of the frequency of the first oscillating flow rate.
17 . The system of claim 14 , wherein the first oscillating flow rate is in sync with the second oscillating flow rate.
18 . The system of claim 14 , wherein the first oscillating flow rate is phase shifted with respect to the second oscillating flow rate.
19 . A method for hydraulic fracturing, comprising:
estimating a natural frequency of a first wellbore based on a pressure wave response from the first wellbore or a pressure wave response from a second wellbore;
controlling a first pump system to pump fluid into the first wellbore at a first oscillating flow rate based on the estimated natural frequency of the first wellbore; and
controlling a second pump system to pump fluid into the second wellbore at a second oscillating flow rate based on the first oscillating flow rate or the pressure wave response from the second wellbore.
20 . The method of claim 19 , wherein the first pump system is on a pad, and the second pump system is on the pad.
21 . The method of claim 19 , wherein the first pump system is on a first pad, and the second pump system is on a second pad spaced apart from the first pad.
22 . A method for hydraulic fracturing, comprising:
estimating a natural frequency of a wellbore based on a pressure wave response from the wellbore; and
controlling a pump system to pump fluid into the wellbore at an oscillating flow rate having a frequency within 10% of the natural frequency of the wellbore or a harmonic of the natural frequency of the wellbore.
23 . The method of claim 22 , further comprising re-estimating the natural frequency of the wellbore, and adjusting the frequency of the oscillating flow rate based on the re-estimated natural frequency.