Abstract
A well system includes an electrical submersible pumping (ESP) assembly, a variable speed drive, and a ride through system. The ESP assembly includes a pump for lifting liquid from inside the well and an electric motor for powering the pump. The variable speed drive is outside the well and controls delivery of electricity from a power source to the motor. The ride through system provides backup electricity if there is an interruption of electricity from the power source. The ride through system includes a bank of power modules having stored electrical power. The modules are connected in series and have a combined electrical potential adequate for powering the motor. By selectively disconnecting adjacent modules from one another, the electrical potential from the bank of power modules is reduced to a magnitude that is not hazardous for personnel.
Claims
1. A ride through system for use with an electrical submersible pump (ESP) assembly, the ride through system comprising: a bank of power modules, each power module having an electrical potential connector lines that each have opposing ends connected between sequential power modules; switches in each of the connectors lines that are changeable between an open position and a closed position, when the switches are in the closed position the power modules are arranged in series so that a maximum electrical potential transmissible from the bank of power modules is substantially equal to a sum of the electrical potentials of each of the power modules, and when in the open position the maximum electrical potential transmissible from the bank of power modules is equal to an electrical potential of a one of the power modules; and a controller configured to cause the switches to move between the open and closed positions and to provide electrical communication from the bank of power modules to the ESP.
2. The ride through system of claim 1, wherein when the switches are in the open position the ride through system is in a deactivated mode and when each switch is in a closed position the ride through system is in a standby mode.
3. The ride through system of claim 2, further comprising an interlock coupled to the switches, that selectively moves the switches between the open and closed positions, and wherein the interlock is in communication with the controller and is responsive to commands from the controller.
4. The ride through system of claim 1, wherein the maximum electrical potential from each of the power modules is 50 V and wherein the electrical potential from the bank of power modules to the ESP is 100 V.
5. The ride through system of claim 1, wherein the power modules are selected from the group consisting of a battery, a capacitor, a super capacitor, and combinations.
6. The ride through system of claim 1, wherein a variable speed drive for controlling electricity to the ESP assembly is in selective electrical communication with the bank of power modules.
7. The ride through system of claim 1, further comprising a recharging power source for recharging the power modules.
8. The ride through system of claim 7, wherein the recharging power source is the same as a power source for providing electrical power to the ESP assembly.
9. The ride through system of claim 1, wherein the magnitude of electrical potential in each of the power modules are at values selected from the group consisting of values that are substantially equal to one another, values that are different from one another, values that are substantially the same as others and different from others, and combinations.
10. The ride through system of claim 5, wherein the power modules are comprised of an arrangement of series and parallel configurations.
Description
BRIEF DESCRIPTION OF DRAWINGS
(1) Some of the features and benefits of the present invention having been stated, others will become apparent as the description proceeds when taken in conjunction with the accompanying drawings, in which:
(2) FIG. 1 is a side partial sectional view of an example of a well system that includes an electrical submersible pumping system and a variable speed drive.
(3) FIG. 2A is a schematic example of a ride through system for use with the variable speed drive of FIG. 1, the ride through system being in a standby mode.
(4) FIG. 2B is a schematic example of the ride through system of FIG. 2A in a deactivated mode.
(5) While subject matter is described in connection with embodiments disclosed herein, it will be understood that the scope of the present disclosure is not limited to any particular embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents thereof.
DETAILED DESCRIPTION OF INVENTION
(6) The method and system of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings in which embodiments are shown. The method and system of the present disclosure may be in many different forms and should not be construed as limited to the illustrated embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey its scope to those skilled in the art. Like numbers refer to like elements throughout. In an embodiment, usage of the term about includes +/5% of a cited magnitude. In an embodiment, the term substantially includes +/5% of a cited magnitude, comparison, or description. In an embodiment, usage of the term generally includes +/10% of a cited magnitude.
(7) It is to be further understood that the scope of the present disclosure is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. In the drawings and specification, there have been disclosed illustrative embodiments and, although specific terms are employed, they are used in a generic and descriptive sense only and not for the purpose of limitation.
(8) In FIG. 1 is a side partial sectional view of an example of a well system 10 that includes an electrical submersible pumping (ESP) assembly 12 for artificially lifting liquid from within a well 14, which intersects a formation 16. ESP assembly 12 includes a pump 17 having impellers 18 and diffusers 19 stacked alternatingly between the impellers 18. Rotating impellers 18 within the stationary diffusers 19 lifts liquid from within the well 14 upwards through production tubing 20 to surface. An inlet 21 is formed through a sidewall of the housing of pump 17, which provides a path for the liquid to enter into pump 17 and into contact with the impellers 18 and diffusers 19. The upper end of production tubing 20 terminates within a wellhead assembly 22 shown on surface. Inside wellhead assembly 22 liquid in production tubing 20 is transferred into a production line 24 shown extending laterally from wellhead assembly 22. In alternatives, production line 24 transports fluid distally from wellsite. ESP assembly 12 also includes an electrical motor 26, a connected shaft 27 shown in dashed outline having an end rotationally affixed to motor 26, and an opposing end coupled with the impellers 18. A seal section 28 for equalizing pressure within motor 26 is included with assembly 12, which is shown between motor 26 and pump 17 and intersected by shaft 27.
(9) Well system 10 includes an electrical supply system 30 for is providing electricity to the motor 26. For the purposes of discussion herein, in an example electricity means a flow of electrons and measurable in terms of electrical current, and having a potential energy measurable in terms of voltage. Supply system 30 includes a power source 32, which in examples includes alternating current and optionally provides three-phase power for driving motor 26. Examples of power source 32 include an electrical utility, a generator, and a renewable source. In the example of FIG. 1, line 34 connects power source 32 to a motor controller 36, such as a variable speed drive or other similar device. Examples of variable speed drive 36 include a pulse with modulated variable frequency drive, or other known controllers for varying current or voltage within the electricity being delivered from power source 32 which is used for varying the rotational speed of motor 26. In the example shown, power source 32 and variable speed drive 36 are on surface and outside of wellbore 14. A controller 38 is shown included with variable speed drive 36 and which in examples monitors characteristics of the electricity provided from power source 32 and includes means for adjusting operation of variable speed drive 36 in response to changes in characteristics of the electricity provided through power source 32. Shown in dashed outline within variable speed drive 36 is a ride-through system 40, which as explained in more detail below, includes stored electrical energy for providing power to motor 26 in instances when electricity from power source 32 is temporarily suspended or otherwise unavailable. A line 42 is shown electrically connecting variable speed drive 36 to a transformer 44. A power cable 46 extends from an output of transformer 46, through wellhead assembly 22 and into wellbore 14. An end of power cable 46 opposite transformer 44 connects to a splice 48, which provides connection to a motor lead extension 50 (which is optionally part of the power cable 46). Motor lead extension 50 terminates at a pothead connector 52 shown mounted onto motor 26 and provides electrical connection from the motor lead extension 50 to the motor 26. Further shown in FIG. 1 is that wellbore 14 is lined with casing 54, perforations 56 extend radially through the sidewalls of casing 54 that permit the flow of fluid F from within formation 16 and to within inside of casing 54.
(10) Shown in FIG. 2A is a schematic example of ride-through system 40. Electrically conducting leads 58, 60 are on opposing ends of ride-through system 40, and provide electrical communication between ride-through system 40 and variable speed drive 36. The ride-through system 40 of FIG. 2A includes power modules 62.sub.1-n. Examples of the power modules 62.sub.1-n include batteries, capacitors, super capacitors, or any device capable of retaining a designated amount of stored electrical energy for a particular period of time. The modules 62.sub.1-n each have a positive lead (+) and a negative lead (), and during the particular period of time when the electrical energy is stored in the modules 62.sub.1-n, an electrical potential exists between the positive and negative leads. In a non-limiting example, the electrical energy stored in the modules 62.sub.1-n, which is alternatively referred to as power capacity and is expressed in terms of Watt-hours. In the illustrated embodiment the modules 62.sub.1-n are arranged in series so that the electrical potential difference between lead 58 and lead 60 is substantially equal to the combined electrical potentials across each one of the modules 62.sub.1-n (i.e., across their respective positive and negative leads), and which defines the electrical potential of the ride-through system 40. Further illustrated in FIG. 2A is that a bank of modules 63 is defined by the power modules 62.sub.1-n connected in series. In alternatives (not shown), the power modules 62.sub.1-n are arranged in a combination of parallel and series configurations.
(11) Connector lines 64.sub.1-n extend between sequential ones of the power modules 62.sub.1-n and within each of lines 64.sub.1-n are switches 66.sub.1-n that are shown in a closed configuration in FIG. 2A. For the purposes of discussion herein, sequential or arranged sequentially defines an arrangement in which the power modules 62.sub.1-n are connected in an electrical circuit, e.g., end to end, such that terminals on the modules 62.sub.1-n connect to terminals having a different polarity. Charging power sources 68.sub.1-n are shown connected across each of the power modules 62.sub.1-n via connector lines 70.sub.1-n, 72.sub.1-n that provide electrical communication to the positive and negative terminals respectively of each of the power modules 62.sub.1-n. Optionally, recharging power sources 68.sub.1-n are made up of a single power source (not shown) that connects to the power modules 62.sub.1-n along connector lines 70.sub.1-n, 72.sub.1-n; optionally, the single power source is the power source 32. In the example of FIG. 2A, the switches 66.sub.1-n being in the closed configuration is referred to as a standby mode. When in the standby mode and a loss of power or drop of power from power source 32 is sensed by controller 38, internal switching (not shown) provides electrical communication between ride-through module 40 and line 42, so that electricity flows from the modules 62.sub.1-n in the ride-through module 40 to the ESP assembly 12 (FIG. 1) via line 42. Further in this example, the electrical energy stored in modules 62.sub.1-n provides a threshold magnitude of electrical potential and current to motor 26 and causing motor 26 to exert a rotational torque to the shaft 27 and attached impellers 18. In an embodiment, the rotational torque is applied to the impellers 18 in the same rotational direction for lifting liquid by operation of the pump 17 (pumping direction), which is opposite to the rotational direction of the impellers 18 occurring during backspin (backspin direction), and the magnitude of the rotational torque is at least that of a rotational torque applied to the impellers 18 from a static head of liquid in and above the pump 17. Exerting a rotational torque against the impellers 18 in this direction and magnitude opposes and/or prevents backspin as the impellers 18 are either maintained in a rotationally stationary position or are rotated in the pumping direction. Further embodiments exist in which the rotational torque from the motor 26 while being energized by the ride through module 40, rotates the impellers 18 at a rate that prevents backflow.
(12) Still referring to FIG. 2A, an interlock 74 is shown having legs coupled with each of the switches 66.sub.1-n, as described in more detail below interlock 74 provides a means for reconfiguring switches 66.sub.1-n from the closed position shown in FIG. 2A and into an open configuration. Communication means 76, which in examples is wireless, hard-wired, or fiber optics, provides signal communication between controller 38 and interlock 74. Referring now to FIG. 2B, a schematic example of the ride-through system 40 is shown in a deactivated mode. In the deactivated mode the switches 66.sub.1-n are in an open configuration so that each of the power modules 62.sub.1-n are disconnected and electrically isolated from one another. In a non-limiting example, the switches 66.sub.1-n are moved into the open position by operation of the interlock 74. In alternatives, the interlock 74 operates in response to receiving an activation signal from controller 38 via communication means 76. In the deactivated mode, and with sequential power modules 62.sub.1-n electrically isolated from one another, the maximum electrical potential transmittable from the ride-through system 40 is no greater than the maximum electrical potential available from any one of the power modules 62.sub.1-n, that as across their respective positive and negative terminals. In examples, electricity that is transmittable is that which is conducted, or able to be conducted. In embodiments, the maximum electrical potential in any one of the power modules 62.sub.1-n is at or below a threshold magnitude that is hazardous to personnel, which in one example is about 50 V. In examples when the ride-through module 40 is in the deactivated configuration, operations personnel freely handle the ride-through module 40 without personal protection equipment and without draining electrical energy from the power modules 62.sub.1-n.
(13) In a non-limiting example of operation, electricity from power source 32 (FIG. 1) is received by variable speed drive 36, where it in combination with commands from controller 38, condition the electricity for use by motor 26 to power the pump 17 so that liquid inside well 14 is lifted to wellhead assembly 22. When the supply of electricity from power source 32 is interrupted, which in examples occurs for a period measured in milli-seconds to in excess of many minutes, ride-through system 40 of FIG. 2A is put into electrical communication with ESP assembly 12 for temporarily providing electricity to motor 26. Upon resumption of the supply of electricity from power source 32, ride-through system 40 is disconnected from ESP assembly 12 and one or more of power modules 62.sub.1-n are recharged using recharging power source(s) 68.sub.1-n. While power modules 62.sub.1-n have a substantially full charge, the interlock 74 is operated to reconfigure the ride-through system 40 from the standby mode of FIG. 2A to the deactivated mode shown in FIG. 2B. When in the deactivated mode, maintenance, service, repair, or replacement of all or a part of the ride-through system 40 is performed. Further in this example, upon completion of service, maintenance, or other handling by operations personnel of the ride-through module 40 when in the deactivated mode, a signal is generated from controller via communication means to interlock 74 to reconfigure. switches 66.sub.1-n into the standby mode of FIG. 2A, which in a loss of power, as monitored through controller 38, motor 26 is optionally powered from electricity from the ride-through system 40. In alternatives, the interlock 74 moves switches 66.sub.1-n between the open and closed position simultaneously, or at different times, such as in a particular sequence.
(14) In embodiments, controller 38 includes a processor and a non-transitory computer-readable memory accessible by the processor and having executable code stored thereon. The executable code includes a set of instructions that causes a processor to perform operations that include operating the interlock 74, adjusting operation of the variable speed drive 36, and connecting rid-through system 40 with the ESP assembly 12. Examples of processor include a multicore processor with nodes such as those from Intel Corporation or Advanced Micro Devices (AMD), or an HPC Linux cluster computer. Process optionally is a mainframe computer of any conventional type of suitable processing capacity such as those available from International Business Machines (IBM) of Armonk, N.Y. or other source; or alternatively is a computer of any conventional type of suitable processing capacity, such as a personal computer, laptop computer, or any other suitable processing apparatus. It should thus be understood that a number of commercially available data processing systems and types of computers may be used for this purpose.
(15) The present invention described herein, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned, as well as others inherent therein. While a presently preferred embodiment of the invention has been given for purposes of disclosure, numerous changes exist in the details of procedures for accomplishing the desired results. These and other similar modifications will readily suggest themselves to those skilled in the art, and are intended to be encompassed within the spirit of the present invention disclosed herein and the scope of the appended claims.
