Well fracturing systems with electrical motors and methods of use
AssigneeStewart & Stevenson LLC
InventorsMark Payne, Haomin Lin, Tom Robertson
Life of this patent
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Abstract
A system for stimulating oil or gas production from a wellbore includes a hydraulic fracturing pump unit having one or more hydraulic fracturing pumps driven by one or more electrical fracturing motors, a variable frequency drive (VFD) controlling the electrical fracturing motors, a fracturing pump blower unit driven by a blower motor, and a fracturing pump lubrication unit having a lubrication pump driven by a lubrication motor and a cooling fan driven by a cooling motor. The system may further include a blender unit and a hydration unit. A system control unit may control the operational parameters of the system.
Claims9
A method for stimulating oil or gas production from a wellbore using an electrically powered fracturing system, the method comprising:
- a) establishing a fluid connection between a hydraulic fracturing system and the wellbore, wherein the hydraulic fracturing system comprises at least one hydraulic fracturing pump unit, an electrical fracturing blender unit, and a control unit connected to the least one hydraulic fracturing pump unit and the electrical fracturing blender unit via a data channel, wherein the at least one hydraulic fracturing pump unit includes two or more fluid pumps and wherein each fluid pump is driven by an electric pump motor;
- b) using at least one fluid pump to pump a blended fracturing fluid down the wellbore;
- c) using the control unit to:
- i) initialize and maintain operating parameters of the fluid pumps based on information about the flow rate of each fluid pump;
- ii) control the electric pump motors so to drive the fluid pumps, wherein controlling the electric pump motors includes the steps of:
- A) receiving a target injection pressure and a target injection rate limit;
- B) using an algorithm to adjust the electric pump motors speed set points so as to collectively reach the target injection pressure while not collectively exceeding the injection rate limit using predicted values for κ - intrinsic permeability;
- u - viscosity, and Vp- pressure gradient vector to calculate a discharge rate per unit area, q, and using q to computationally predict at least one of the change in injection pressure which will result from a proposed change in speed of any combination of the electric pump motors and the change in injection rate required to reach a desired injection pressure, and wherein q is calculated using κ, u, and Vp in the following equation:
- q
- =
- -
- κ
- μ
- ·
- ∇
- p
- ;
- and
- iii) control at least one electrical blending motor to produce a fracturing fluid from the electrical fracturing blender unit.
A system control unit for use with a system for stimulating oil or gas production from a wellbore, the system control unit comprising:
- (a) a hydraulicfracturing pump unit controllerconfigured to control a hydraulic fracturing pump unit having one or more electric pump motors and one or more fluid pumps, wherein each fluid pump is driven by an electric pump motor, wherein the hydraulic fracturing pump unit controllercontrols the electric pump motors, and wherein controlling of the electric pump motors includes:
- A) receiving a target injection pressure and a target injection rate limit;
- B) using an algorithm to adjust the electric pump motors speed set points so as to collectively reach the target injection pressure while not collectively exceeding the injection rate limit;
- (b) a hydraulic blender unit controller configured to control a hydraulic blender pump unit having one or more hydraulic blenderelectrical motors;
- wherein the hydraulic fracturing pump unit controller uses predicted values for ϰ- intrinsic permeability;
- u - viscosity, and Vp- pressure gradient vector to calculate a discharge rate per unit area, q, and using q to computationally predict at least one of the change in injection pressure which will result from a proposed change in speed of any combination of the electric pump motors and the change in injection rate required to reach a desired injection pressure, and wherein q is calculated using ϰ, u, and Vp in the following equation:
- q
- =
- -
- κ
- μ
- ·
- ∇
- p
- .
Dependencies are inferred from the claim text.