| CPC E21B 43/2607 (2020.05) [F04B 23/04 (2013.01)] | 26 Claims |
|
1. A method of operating a plurality of hydraulic fracturing units, each of the hydraulic fracturing units including a hydraulic fracturing pump to pump fracturing fluid into a wellhead and an internal combustion engine to drive the hydraulic fracturing pump, the method comprising:
receiving, via a supervisory controller one or more rate ramp signals indicative of a rate ramp operational mode to control a flow rate associated with pumping fracturing fluid into a wellhead;
receiving, via the supervisory controller, one or more operational parameters associated with pumping fracturing fluid into the wellhead, the one or more operational parameters including one or more of a target flow rate, a maximum flow rate, a target pressure, or a pressure range for fracturing fluid supplied to the wellhead;
determining, via the supervisory controller, whether the plurality of hydraulic fracturing units have a capacity sufficient to achieve the one or more of the target flow rate or the target pressure;
initiating operation of at least some of the plurality of hydraulic fracturing units;
increasing a flow rate from the at least some of the hydraulic fracturing units according to a controlled increasing flow rate schedule toward the one or more of the target flow rate or the target pressure, the controlled increasing flow rate schedule including two or more different rates of change of flow rate corresponding to two or more wellhead pressure ranges and causing operation of the hydraulic fracturing units such that a flow rate of fracturing fluid does not exceed the maximum flow rate and a fracturing fluid pressure substantially remains within the pressure range;
determining whether the at least some of the hydraulic fracturing units have achieved the one or more of the target flow rate or the target pressure;
receiving one or more signals indicative of a blender output upstream of the plurality of hydraulic fracturing units;
controlling operation of each of the at least some hydraulic fracturing units based at least in part on the one or more signals indicative of the blender output;
one or more of:
when it has been determined that the one or more of the target flow rate or the target pressure has been achieved, operating the at least some hydraulic fracturing units to maintain one or more of the target flow rate or the target pressure;
when it has been determined that the target flow rate has not been achieved, generating one or more signals indicative of a failure to achieve the target flow rate; or
when it has been determined that the target pressure has not been achieved, operating the at least some hydraulic fracturing units to maintain a maximum flow rate;
receiving, via the supervisory controller, one or more signals indicative of a maximum fluid pressure at the wellhead;
monitoring fluid pressure at the wellhead; and
when the fluid pressure at the wellhead increases to within an upper range of the maximum fluid pressure, causing two or more of:
generating one or more signals indicative of the fluid pressure being within the upper range of the maximum fluid pressure;
reducing a rate of change of the flow rate provided by the at least some of the hydraulic fracturing units; or
reducing the target flow rate.
|