WO2017023320A1

WO2017023320A1 - Electric submersible pump internal fluidics system

Info

Publication number: WO2017023320A1
Application number: PCT/US2015/043900
Authority: WO
Inventors: Alejandro CAMACHO CARDENAS
Original assignee: Schlumberger Canada Limited; Services Petroliers Schlumberger; Schlumberger Technology B.V.; Schlumberger Technology Corporation
Priority date: 2015-08-06
Filing date: 2015-08-06
Publication date: 2017-02-09

Abstract

An electric submersible pump (ESP) can include a shaft that includes an axis; a pump mechanism operatively coupled to the shaft; an electric motor that drives the shaft and that includes an electric motor housing that defines at least a portion of a dielectric oil chamber; and a fluidics system that controls flow of well fluid within the electric motor housing to reduce contamination of the dielectric oil.

Description

ELECTRIC SUBMERSIBLE PUMP INTERNAL FLUIDICS SYSTEM

BACKGROUND

[0001] As an example, an electric submersible pump (ESP) can include a stack of impeller and diffuser stages where the impellers are operatively coupled to a shaft driven by an electric motor. As an example, an electric submersible pump (ESP) can include a piston that is operatively coupled to a shaft driven by an electric motor, for example, where at least a portion of the shaft may include one or more magnets and form part of the electric motor.

SUMMARY

[0002] An electric submersible pump (ESP) can include a shaft that includes an axis; a pump mechanism operatively coupled to the shaft; an electric motor that drives the shaft and that includes an electric motor housing that defines at least a portion of a dielectric oil chamber; and a fluidics system that controls flow of well fluid within the electric motor housing to reduce contamination of the dielectric oil. A method can include operating an electric submersible pump (ESP); sensing internal well fluid within a portion of the electrical submersible pump (ESP) that includes dielectric oil; and actuating at least one component within the electrical submersible pump (ESP) to control flow of at least a portion of the internal well fluid. A fluidics system of an electric submersible pump can include a fluid sensor that senses leakage fluid; a controller that includes an interface operatively coupled to the fluid sensor; and a component actuatable by the controller based at least in part on leakage fluid sensed by the fluid sensor.

[0003] This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Features and advantages of the described implementations can be more readily understood by reference to the following description taken in conjunction with the accompanying drawings.

[0005] Fig. 1 illustrates examples of equipment in geologic environments; [0006] Fig. 2 illustrates an example of an electric submersible pump system;

[0007] Fig. 3 illustrates examples of equipment;

[0008] Fig. 4 illustrates an example of a system;

[0009] Fig. 5 illustrates an example of a portion of a system;

[0010] Fig. 6 illustrates an example of a system;

[0011] Fig. 7 illustrates an example of a system;

[0012] Fig. 8 illustrates an example of a portion of a system, an example of a micro-pump and an example of a micro-valve;

[0013] Fig. 9 illustrates examples of pumps;

[0014] Fig. 10 illustrates an example of a method;

[0015] Fig. 1 1 illustrates an example of a system; and

[0016] Fig. 12 illustrates example components of a system and a networked system.

DETAILED DESCRIPTION

[0017] The following description includes the best mode presently

contemplated for practicing the described implementations. This description is not to be taken in a limiting sense, but rather is made merely for the purpose of describing the general principles of the implementations. The scope of the described implementations should be ascertained with reference to the issued claims.

[0018] Fig. 1 shows examples of geologic environments 120 and 140. In Fig. 1 , the geologic environment 120 may be a sedimentary basin that includes layers (e.g., stratification) that include a reservoir 121 and that may be, for example, intersected by a fault 123 (e.g., or faults). As an example, the geologic environment 120 may be outfitted with any of a variety of sensors, detectors, actuators, etc. For example, equipment 122 may include communication circuitry to receive and to transmit information with respect to one or more networks 125. Such information may include information associated with downhole equipment 124, which may be equipment to acquire information, to assist with resource recovery, etc. Other equipment 126 may be located remote from a well site and include sensing, detecting, emitting or other circuitry. Such equipment may include storage and communication circuitry to store and to communicate data, instructions, etc. As an example, one or more satellites may be provided for purposes of communications, data acquisition, etc. For example, Fig. 1 shows a satellite in communication with the network 125 that may be configured for communications, noting that the satellite may additionally or alternatively include circuitry for imagery (e.g., spatial, spectral, temporal, radiometric, etc.).

[0019] Fig. 1 also shows the geologic environment 120 as optionally including equipment 127 and 128 associated with a well that includes a substantially horizontal portion that may intersect with one or more fractures 129. For example, consider a well in a shale formation that may include natural fractures, artificial fractures (e.g., hydraulic fractures) or a combination of natural and artificial fractures. As an example, a well may be drilled for a reservoir that is laterally extensive. In such an example, lateral variations in properties, stresses, etc. may exist where an

assessment of such variations may assist with planning, operations, etc. to develop the reservoir (e.g., via fracturing, injecting, extracting, etc.). As an example, the equipment 127 and/or 128 may include components, a system, systems, etc. for fracturing, seismic sensing, analysis of seismic data, assessment of one or more fractures, etc.

[0020] As to the geologic environment 140, as shown in Fig. 1 , it includes two wells 141 and 143 (e.g., bores), which may be, for example, disposed at least partially in a layer such as a sand layer disposed between caprock and shale. As an example, the geologic environment 140 may be outfitted with equipment 145, which may be, for example, steam assisted gravity drainage (SAGD) equipment for injecting steam for enhancing extraction of a resource from a reservoir. SAGD is a technique that involves subterranean delivery of steam to enhance flow of heavy oil, bitumen, etc. SAGD can be applied for Enhanced Oil Recovery (EOR), which is also known as tertiary recovery because it changes properties of oil in situ.

[0021] As an example, a SAGD operation in the geologic environment 140 may use the well 141 for steam-injection and the well 143 for resource production. In such an example, the equipment 145 may be a downhole steam generator and the equipment 147 may be an electric submersible pump (e.g., an ESP).

[0022] As illustrated in a cross-sectional view of Fig. 1 , steam injected via the well 141 may rise in a subterranean portion of the geologic environment and transfer heat to a desirable resource such as heavy oil. In turn, as the resource is heated, its viscosity decreases, allowing it to flow more readily to the well 143 (e.g., a resource production well). In such an example, equipment 147 (e.g., an ESP) may then assist with lifting the resource in the well 143 to, for example, a surface facility (e.g., via a wellhead, etc.). As an example, where a production well includes artificial lift equipment such as an ESP, operation of such equipment may be impacted by the presence of condensed steam (e.g., water in addition to a desired resource). In such an example, an ESP may experience conditions that may depend in part on operation of other equipment (e.g., steam injection, operation of another ESP, etc.).

[0023] Conditions in a geologic environment may be transient and/or persistent. Where equipment is placed within a geologic environment, longevity of the equipment can depend on characteristics of the environment and, for example, duration of use of the equipment as well as function of the equipment. Where equipment is to endure in an environment over an extended period of time, uncertainty may arise in one or more factors that could impact integrity or expected lifetime of the equipment. As an example, where a period of time may be of the order of decades, equipment that is intended to last for such a period of time may be constructed to endure conditions imposed thereon, whether imposed by an environment or environments and/or one or more functions of the equipment itself.

[0024] Fig. 2 shows an example of an ESP system 200 that includes an ESP 210 as an example of equipment that may be placed in a geologic environment. As an example, an ESP may be expected to function in an environment over an extended period of time (e.g., optionally of the order of years). As an example, commercially available ESPs (such as the REDA™ ESPs marketed by

Schlumberger Limited, Houston, Texas) may find use in applications that call for, for example, pump rates in excess of about 4,000 barrels per day and lift of about 12,000 feet or more.

[0025] In the example of Fig. 2, the ESP system 200 includes a network 201 , a well 203 disposed in a geologic environment (e.g., with surface equipment, etc.), a power supply 205, the ESP 210, a controller 230, a motor controller 250 and a VSD unit 270. The power supply 205 may receive power from a power grid, an onsite generator (e.g., natural gas driven turbine), or other source. The power supply 205 may supply a voltage, for example, of about 4.16 kV.

[0026] As shown, the well 203 includes a wellhead that can include a choke (e.g., a choke valve). For example, the well 203 can include a choke valve to control various operations such as to reduce pressure of a fluid from high pressure in a closed wellbore to atmospheric pressure. Adjustable choke valves can include valves constructed to resist wear due to high-velocity, solids-laden fluid flowing by restricting or sealing elements. A wellhead may include one or more sensors such as a temperature sensor, a pressure sensor, a solids sensor, etc.

[0027] As to the ESP 210, it is shown as including cables 21 1 (e.g., or a cable), a pump 212, gas handling features 213, a pump intake 214, a motor 215, one or more sensors 216 (e.g., temperature, pressure, strain, current leakage, vibration, etc.) and optionally a protector 217.

[0028] As an example, an ESP may include a REDA™ HOTLINE™ high- temperature ESP motor. Such a motor may be suitable for implementation in a thermal recovery heavy oil production system, such as, for example, SAGD system or other steam-flooding system.

[0029] As an example, an ESP motor can include a three-phase squirrel cage with two-pole induction. As an example, an ESP motor may include steel stator laminations that can help focus magnetic forces on rotors, for example, to help reduce energy loss. As an example, stator windings can include copper and insulation.

[0030] In the example of Fig. 2, the well 203 may include one or more well sensors 220, for example, such as the commercially available OPTICLINE™ sensors or WELLWATCHER BRITEBLUE™ sensors marketed by Schlumberger Limited (Houston, Texas). Such sensors are fiber-optic based and can provide for real time sensing of temperature, for example, in SAGD or other operations. As shown in the example of Fig. 1 , a well can include a relatively horizontal portion. Such a portion may collect heated heavy oil responsive to steam injection. Measurements of temperature along the length of the well can provide for feedback, for example, to understand conditions downhole of an ESP. Well sensors may extend thousands of feet into a well (e.g., 4,000 feet or more) and beyond a position of an ESP.

[0031] In the example of Fig. 2, the controller 230 can include one or more interfaces, for example, for receipt, transmission or receipt and transmission of information with the motor controller 250, a VSD unit 270, the power supply 205 (e.g., a gas fueled turbine generator, a power company, etc.), the network 201 , equipment in the well 203, equipment in another well, etc.

[0032] As shown in Fig. 2, the controller 230 may include or provide access to one or more modules or frameworks. Further, the controller 230 may include features of an ESP motor controller and optionally supplant the ESP motor controller 250. For example, the controller 230 may include the UN ICONN™ motor controller 282 marketed by Schlumberger Limited (Houston, Texas). In the example of Fig. 2, the controller 230 may access one or more of the PIPESIM™ framework 284, the ECLIPSE™ framework 286 marketed by Schlumberger Limited (Houston, Texas) and the PETREL™ framework 288 marketed by Schlumberger Limited (Houston, Texas) (e.g., and optionally the OCEAN™ framework marketed by Schlumberger Limited (Houston, Texas)).

[0033] In the example of Fig. 2, the motor controller 250 may be a

commercially available motor controller such as the UNICONN™ motor controller. The UN ICONN™ motor controller can connect to a SCADA system, the

ESPWATCHER™ surveillance system, etc. The UNICONN™ motor controller can perform some control and data acquisition tasks for ESPs, surface pumps or other monitored wells. The UNICONN™ motor controller can interface with the

PHOENIX™ monitoring system, for example, to access pressure, temperature and vibration data and various protection parameters as well as to provide direct current power to downhole sensors (e.g., sensors of a gauge, etc.). The UNICONN™ motor controller can interface with fixed speed drive (FSD) controllers or a VSD unit, for example, such as the VSD unit 270.

[0034] For FSD controllers, the UN ICONN™ motor controller can monitor ESP system three-phase currents, three-phase surface voltage, supply voltage and frequency, ESP spinning frequency and leg ground, power factor and motor load.

[0035] For VSD units, the UNICONN™ motor controller can monitor VSD output current, ESP running current, VSD output voltage, supply voltage, VSD input and VSD output power, VSD output frequency, drive loading, motor load, three- phase ESP running current, three-phase VSD input or output voltage, ESP spinning frequency, and leg-ground.

[0036] In the example of Fig. 2, the ESP motor controller 250 includes various modules to handle, for example, backspin of an ESP, sanding of an ESP, flux of an ESP and gas lock of an ESP. The motor controller 250 may include any of a variety of features, additionally, alternatively, etc.

[0037] In the example of Fig. 2, the VSD unit 270 may be a low voltage drive (LVD) unit, a medium voltage drive (MVD) unit or other type of unit (e.g., a high voltage drive, which may provide a voltage in excess of about 4.16 kV). As an example, the VSD unit 270 may receive power with a voltage of about 4.16 kV and control a motor as a load with a voltage from about 0 V to about 4.16 kV. The VSD unit 270 may include commercially available control circuitry such as the

SPEEDSTAR™ MVD control circuitry marketed by Schlumberger Limited (Houston, Texas).

[0038] Fig. 3 shows cut-away views of examples of equipment such as, for example, a portion of a pump 320, a protector 370 and a motor 350 of an ESP. The pump 320, the protector 370 and the motor 350 are shown with respect to cylindrical coordinate systems (e.g., r, z, Θ). Various features of equipment may be described, defined, etc. with respect to a cylindrical coordinate system. As an example, a lower end of the pump 320 may be coupled to an upper end of the protector 370 and a lower end of the protector 370 may be coupled to an upper end of the motor 350. As shown in Fig. 3, a shaft segment of the pump 320 may be coupled via a connector to a shaft segment of the protector 370 and the shaft segment of the protector 370 may be coupled via a connector to a shaft segment of the motor 350. As an example, an ESP may be oriented in a desired direction, which may be vertical, horizontal or other angle. Orientation of an ESP with respect to gravity may be considered as a factor, for example, to determine ESP features, operation, etc.

[0039] Fig. 4 shows an example of a system 400 that may be defined via a top end 402 and a bottom end 404 along a z-axis. As shown, the system 400 includes a shaft 405 that is disposed at least in part in a chamber 406 and a chamber 407. In such an example, dielectric oil may be in the chamber 407 where the chamber 407 is in fluid communication with a conduit 408 that may be in fluid communication with a source of dielectric oil 409. The chamber 407 may be referred to as a dielectric oil chamber and the conduit 408 may be referred to as a dielectric oil conduit. For example, the chamber 407 may be a chamber of a motor such as, for example, the motor 350 of Fig. 3. As an example, the source of the dielectric oil 409 may be a protector such as, for example, the protector 370 of Fig. 3. The source of dielectric oil 409 may help to protect a motor by providing a supply of dielectric oil.

[0040] As an example, a protector can help to avoid well fluid entry to a motor. A protector can include features that act as reservoirs for dielectric oil. For example, a protector can include a labyrinth section that uses the differential weight of fluids to create a barrier and a maze that well fluid would have to travel through before it enters a motor; a protector can include a positive seal protector, or elastomer bag, that provides a barrier between well fluid and dielectric oil; and/or a protector can include one or more bellows that act as a positive seal to well fluid. A protector can help to balance internal pressure of well fluid and, for example, can help to carry thrust load of a pump of an electric submersible pump.

[0041] Referring to Fig. 4, the system 400 is shown as including housing sections 410, 420 and 430 where welds 421 and 43 1 and seal elements 423 and 433 act to seal interfaces between the housing sections 410, 420 and 430. For example, the weld 421 and the seal element 423 act to seal the chamber 406 from intrusion of well fluid while the weld 431 and the seal element 433 act to seal the chamber 407 from intrusion of well fluid. In the example of Fig. 4, the housing section 410 may be coupled to a protector. For example, the shaft 405 may be fit with a coupling 41 1 that can couple the shaft 405 to another shaft that extends through a protector to a pump (see, e.g., the pump 320, the protector 370 and the motor 350 of Fig. 3).

[0042] Well fluid entry into sensitive locations such as those associated with a motor and/or a protector may affect performance and/or longevity of an electric submersible pump. Well fluid entry can be quite slow and, over time, it may accumulate in enough quantities to be detrimental. At times, well fluid entry can be quite rapid, for example, occurring over a relatively short period of time.

Accumulation of fluid within a system can depend on rate of entry, duration and frequency of entry. As an example, an electric submersible pump can include one or more internal fluidics systems that can act to handle fluid that may enter a protector and/or a motor. For example, an internal fluidics system may act to dispose (e.g., drain out to a wellbore) accumulated well fluid inside one or more portions of an ESP.

[0043] As an example, an internal fluidics system may include one or more valve mechanisms that can be actuated (e.g., automatically or on command) to drain at least a portion of well fluid accumulated inside an ESP.

[0044] As an example, a valve mechanism may be operatively coupled to circuitry that may include, for example, one or more water (e.g., or well fluid) sensors. Such an arrangement may act to control timing of opening and closing of one or more valves.

[0045] As an example, an internal fluidics system may include one or more pumps. For example, consider a diaphragm pump, a peristaltic pump, or other type of pump that can move fluid within a protector and/or a motor of an ESP. As an example, a pump or pumps may be operatively coupled to circuitry that may include one or more sensors and/or one or more interfaces that can receive signals that can control operation of a pump or pumps.

[0046] As an example, an internal fluidics system can include one or more internal fluid routing features. For example, well fluid may tend to accumulate in one or more locations where a channel or channels may be in fluid communication with such one or more locations to direct well fluid to a location or locations that may mitigate detrimental accumulation of such well fluid.

[0047] As an example, an internal fluidics system may operate to replenish dielectric oil to an ESP, for example, where an amount of well fluid is disposed, which may include some amount of dielectric oil.

[0048] As an example, an ESP can include one or more valve mechanisms that can be actuated (e.g., automatically and/or on command) to drain at least a portion of well fluid accumulated in one or more undesired places (e.g., one or more internal locations of the ESP).

[0049] As an example, a valve can be located where well fluid can accumulate and, for example, where it may be detrimental. Some example locations include those associated with a motor pothead, a motor thrust bearing, motor end turns, motor tandem connections, protector seal chambers, a protector thrust bearing, motor and protector internal instrumentation.

[0050] As an example, a valve mechanism may include circuitry, mechanics, etc., such that a valve can be actuated (e.g., closed, opened, positioned, etc.) via one or more of a pressure, chemical and/or electrical signature. As an example, an internal fluidics system of an ESP may be operatively coupled to one or more monitoring systems, which may be disposed downhole and/or at a surface location. As an example, a valve mechanism may be operatively coupled to a downhole ESP monitoring system that can transmit a signal to open/close a valve. As an example, a valve can be remotely actuated, for example, via input of a command by a user, etc.

[0051] As an example, a valve mechanism can be combined with one or more water (or well fluid) sensors to control timing of opening and closing of a valve. In such an example, if one or more of a well oil purity monitoring system, a dielectric oil purity monitoring system, and a water monitoring system, indicates that well fluid has entered a protector and/or a motor and/or accumulated to a certain amount in a protector and/or a motor, a signal may be transmitted that can cause a valve mechanism to actuate a valve or valves and/or one or more other components of an internal fluidics system.

[0052] As an example, consider one or more sensors that can perform one or more functions such as, for example, one or more of detecting presence and quantity of well fluid accumulated at a location where it can be drained, signaling a valve directly as to when to actuate, and signaling an ESP monitoring system (e.g., gauge, etc.) so that it can take one or more appropriate actions as to when to operate a valve. As an example, an ESP monitoring system can actuate a valve based on logic and/or prompt a surface controller and/or a user for action (e.g., optionally signaling a surface control/user directly).

[0053] As mentioned, an internal fluidics system may include one or more pumps (e.g., a local pump at a site and/or a remote pump in fluid communication with a site or site to assist with movement of fluid). As pressure inside an ESP might not readily allow for direct disposal of fluids by opening a valve, a pumping unit can be implemented to build pressure and discard unwanted fluid.

[0054] As mentioned, an ESP can include internal fluid routing features, for example, so that well fluid will tend to accumulate in particular locations that can favor disposal of the well fluid. Some examples of features that can favor internal fluid routing and accumulation in particular locations can include: channeling and routing next to potential well fluid entry points so that well fluid accumulation is driven by gravity and/or centrifugal/hydraulic forces; channeling and routing on locations that are not next to entry points but where the well fluid can pass through; well fluid receptacles that act to isolate well fluid (e.g., from various ESP internals); and well fluid receptacles with geometries that favor their drainage when a valve is actuated to dispose of well fluid.

[0055] As an example, an ESP can include an enhanced oil system that can act to replenish dielectric oil, for example, after disposal of well fluid (e.g., which may include some amount of entrained dielectric oil, may reduce volume, etc.).

[0056] As an example, an ESP oil system can be sized to offer barrier and compensating functions and to provide replenishing oil volume to refill volume reduced via drainage of well fluid. As an example, extra oil volume can be located at one or more locations associated with, for example, protector chambers, protector bodies, a motor compensator, a motor body, and an external tank outside an ESP and within a wellbore.

[0057] As an example, an ESP can include one or more features that can address well fluid entry via one or more of an accumulation approach, a routing approach, a control approach, a disposal approach and a dielectric oil replenishing approach.

[0058] Depending on environment, well fluid entry can be contribute to one or more ESP failure modes such as, for example, one or more of immediate electrical shorting, insulation material degradation and electrical failure, and bearing damage. Well fluid entry may be at times quite slow (e.g., sipping). Well fluid entry may take place at particular locations such as, for example, seal locations (e.g., via welds, O- rings, shaft seals, etc.).

[0059] Fig. 5 shows an example of a portion of a system 500 that includes an upper end 502, a lower end 504, a chamber 506, a chamber 507, a housing section 510, a housing section 520, a housing section 530, a weld 531 and a seal element 533. As shown, the weld 531 and the seal element 533 act to seal a joint formed by the housing sections 520 and 530 where the weld 531 is an exterior surface weld and where the seal element 533 seats in a groove formed in a surface of the housing section 520 and/or a surface of the housing section 530 to seal an internal interface. As an example, a weld and/or a seal element may act to seal one or more interfaces formed by the housing section 510 and the housing section 520.

[0060] In the example of Fig. 5, the housing section 520 includes a cylindrical exterior wall 522 and a cylindrical interior wall 528 where a transition between the walls 522 and 528 includes a recessed groove 526 that rises to a ridge 524. For example, the recessed groove 526 may be disposed between an inwardly facing surface of the cylindrical wall 522 and the ridge 524. As an example, a recessed groove may be a concave well fluid repository (see, e.g., dimension r_r) and, for example, located proximate to a potential an O-ring leakage site, etc. As an example, such a recessed groove may be located at or proximate to a housing joint, a flange joint, a pothead joint, etc.

[0061] In the example of Fig. 5, the housing section 530 includes a cylindrical exterior wall 532 and a cylindrical interior wall 538 where a transition between the walls 532 and 538 includes a recessed groove 536 that rises to a ridge 534. For example, the recessed groove 536 may be disposed between an inwardly facing surface of the cylindrical wall 532 and the ridge 534. As an example, a recessed groove may be a concave well fluid repository. As shown in the example of Fig. 5, the recessed groove 536 is positioned proximate to an interface between the housing section 520 and the housing section 530 where the weld 531 and the seal element 533 act to seal the interface. As an example, the interface may include one or more of threads, bayonets, etc., for example, to couple the housing sections 520 and 530 to each other. As an example, where well fluid enters the interface via a deteriorating weld 531 and via a deteriorating seal element 533, the well fluid may drain and collect in the recessed groove 536. Depending on orientation of the portion of the system 500, the well fluid may remain in the recessed groove 536 rather than flowing elsewhere where its presence may be more detrimental to operation, performance, longevity, etc. of an ESP.

[0062] In the example of Fig. 5, the recessed groove 536 is shown to be in fluid communication with the chamber 507, which can be a dielectric oil chamber of a motor of an ESP. As dielectric oil may be less dense than well fluid (e.g., water or water component of well fluid), the well fluid or a portion thereof may be retained in the recessed groove 536 until it accumulates to a level that rises above the ridge 534, where it may then pour over the ridge 534 to the chamber 507. Once in the chamber 507, such well fluid may travel downwardly (e.g., toward the bottom end 504). In such an example, the well fluid may contact insulation, etc., which may be detrimental to the integrity of the insulation (e.g., insulation of one or more electrical conductors, coils, etc., of an ESP motor).

[0063] Fig. 6 shows an example of a system 600 that includes an upper end 602, a lower end 604, a shaft 605, a chamber 606, a chamber 607, a housing section 610, a housing section 620, a housing section 630, a housing section 640 and a flange 650. In the example of Fig. 6, circles represent approximate example locations where well fluid may enter and a thick line represents a general direction of drainage of well fluid, for example, via one or more of gravity, capillary action, pump action, etc. An oval proximate to the lower end 604 represents a disposal location and/or a reservoir location that can collect well fluid as drained via one or more drainage pathways.

[0064] As an example, one or more concave well fluid repositories may be in fluid communication with one or more drainage pathways (e.g., passages, channels, conduits, etc.). As an example, such one or more pathways may act as a "lymphatic" system for one or more portions of an ESP. As an example, an internal fluidics system can include a network of lymphatic passages that carry well fluid directionally (e.g., lympha meaning water in Latin) to one or more regions to diminish detrimental effects of such well fluid. As an example, a network may act to transport well fluid to a pump, pumps, etc. As an example, a network may include one or more pumps. As an example, an internal fluidics system may include one or more separators (e.g., passive and/or active) that act to separate dielectric oil and water that may be in well fluid. In such an example, the dielectric oil or at least a portion thereof may be retained while the water or at least a portion thereof may be disposed of (e.g., externally and/or internally to a holding reservoir).

[0065] As an example, an internal fluidics system can include passages disposed in housing sections where such passages may optionally be coupled such that flow in one passage of one housing section may continue to flow in a passage of another housing section.

[0066] Fig. 7 shows an example of a system 700 that includes an upper end 702, a lower end 704, a shaft 705, a chamber 706, a chamber 707, a housing section 710, a housing section 720, a housing section 730, a housing section 740 and a flange 750. In the example of Fig. 7, circuitry 770 and sensors 772, 774, 776 and 778 are illustrated where the sensors 772, 774, 776 and 778 are shown at approximate example locations where well fluid may enter and/or flow.

[0067] As an example, one or more water sensors can be located at one or more repositories to monitor water entry levels (e.g., amount of water accumulated, flowing, etc.). As an example, a system may include outputting sensor data to control logic (e.g., surface and/or downhole) where the control logic may be implemented via circuitry (e.g., one or more processors, microprocessors, ARM processors, RISC processors, etc.).

[0068] Fig. 8 shows an example of a portion of a system 800 that includes an upper end 802, a lower end 804, a chamber 806, a chamber 807, a housing section 810, a housing section 820, a housing section 830, a weld 831 and a seal element 833. As shown, the housing section 820 includes wall portions 822 and 828 where a recessed groove 826 is disposed adjacent to a ridge 824. In the example of Fig. 8, the housing section 820 includes a passage 827-1 within the wall portion 828 where the passage 827-1 extends at least in part axially to a lower end 829 of the wall portion 828. [0069] As an example, one or more fluidic components may be mounted in and/or to one or more components of a system. For example, in Fig. 8, an electric micro-pump 880 is mounted in a recess of the housing section 820. As shown, a power source 881 (e.g., a battery or batteries) may be mounted in a recess of the housing section 820 to provide power to the electric micro-pump 880 (e.g., via a micro-pump interface 885). In the example of Fig. 8, the electric micro-pump 880 can receive fluid via an inlet 882 and pump fluid via an outlet 884. The inlet 882 may be in fluid communication with the passage 827-1 (e.g., an inlet passage for well fluid) and the outlet 884 may be in fluid communication with a passage 827-2 (e.g., an outlet passage for well fluid).

[0070] Fig. 8 also shows the housing section 830 as including wall portions 832 and 838 and a recessed groove 836 adjacent to a ridge 834 where a passage 837 extends at least in part axially from the recessed groove 836. As an example, a recessed groove may be annular in shape, for example, spanning about 360 degrees. As an example, a housing section may include a plurality of passages. As an example, a recessed groove may be a "gutter" and may be of an azimuthal span (e.g., in a cylindrical coordinate system) that is less than or equal to about 360 degrees. As an example, a housing section may include a plurality of recessed grooves.

[0071] As an example, the micro-pump 880 may be a piezoelectric micro- pump. As an example, the micro-pump 880 may be constructed of relatively chemically inert materials (e.g., one or more of PTFE, PEEK and perfluoroelastomer etc.). As an example, the micro-pump 880 may include a diaphragm that is operated via a piezoelectric circuit. As an example, the micro-pump 880 may be rated to pump fluid at a rate of the order of milliliters per minute. As an example, the micro- pump 880 may be rated with a pump pressure of the order of about tens of kPa or more.

[0072] Fig. 8 also shows an example of a micro-valve 890 that includes an inlet 892, an outlet 894 and an interface 895. As an example, the system 800 can include one or more valves, which can include one or more micro-valves. As an example, a valve may operate via one or more mechanisms that can be actuated via a control signal. For example, consider one or more of a shape memory alloy mechanism, a rotating element mechanism, a sliding element mechanism, a pinching element mechanism, etc. [0073] Fig. 9 shows examples of micro-pumps 901 and 902. The micro- pumps 901 and 902 may operate via an external and/or an internal power supply. As an example, the micro-pump 901 may be a peristaltic micro-pump that can be mounted within a protector and/or a motor of an ESP.

[0074] As an example, a drain valve may be configured within a system to discard well fluid to a wellbore. As an example, a valve may operate automatically and/or upon receipt of a command. As an example, a valve may operate

automatically according to a timer where the timer may include a selectable timing schedule for opening and/or closing a valve.

[0075] As an example, one or more components of a fluidics system may be powered via power available at a wye point of a multiphase motor. For example, DC power may be transmitted via a multiphase power cable to an ESP motor where the DC power is available via an electrical connection to a wye point of the ESP motor. Such DC power may be used to power a gauge such as, for example, the

gauge/sensor(s) 216 of the ESP 210 of Fig. 2. As an example, an ESP system may include circuitry that can derive power (e.g., DC power) via AC power, which may be, for example, available at a wye point of an ESP motor (e.g., due to an amount of unbalance, etc.). In such examples, one or more electrical conductors may provide power to one or more components of a fluidics system of an ESP (e.g., as may be included in a protector and/or a motor).

[0076] As an example, a gauge mounted to an ESP system may include circuitry that can control operation of one or more components of a fluidics system that can handle well fluid that may enter a housing or housings. As an example, a fluidics system may include one or more micro-pumps and/or micro-valves where dimensions of such micro-pumps and/or micro-valves may be of the order of about 50 mm or less. For example, consider a micro-pump of the order of about 35 mm by about 35 mm by about 10 mm and a micro-valve that may be smaller than such a micro-pump.

[0077] As an example, an ESP that includes an internal fluidics system can include an oversized protector chamber or chambers that can help to replenish volume of fluid as it may be discarded to rid a protector and/or a motor of well fluid. As an example, a protector may include one or more of longer bags and/or bellows, additional parallel bags and/or bellows, longer labyrinths, etc. [0078] Fig. 10 shows an example of a method 1000 that includes an operation block 1010 for operating an electric submersible pump (ESP), a sense block 1020 for sensing internal well fluid within a portion of the electrical submersible pump (ESP) that includes dielectric oil, and an actuation block 1030 for actuating at least one micro-component within the electrical submersible pump (ESP) to control flow of at least a portion of the internal well fluid.

[0079] As an example, the sense block 1020 may sense the internal well fluid, for example, as a type of leakage fluid. A leakage fluid can be a fluid that passes one or more seal elements, component interfaces, etc. such that it migrates from an environment into a space or spaces defined by a housing or housings of an electrical submersible pump (ESP). As an example, a leakage fluid may be water, which may be, for example, one or more of ground water, fresh water and sea water.

[0080] The method 1000 is shown in Fig. 10 in association with various computer-readable media (CRM) blocks 101 1 , 1021 and 1031. Such blocks generally include instructions suitable for execution by one or more processors (or cores) to instruct a computing device or system to perform one or more actions. While various blocks are shown, a single medium may be configured with

instructions to allow for, at least in part, performance of various actions of the method 1000. As an example, a computer-readable medium (CRM) may be a computer-readable storage medium that is non-transitory and not a carrier wave.

[0081] As an example, an electric submersible pump can include one or more pump units for pumping fluid, which may include hydrocarbons from a reservoir (e.g., oil, gas, etc.) in a production mode or, for example, another fluid such as injection fluid (e.g., to assist production, to assist hydraulic fracturing, etc.) in an injection mode.

[0082] An electric submersible pump can be sealed via one or more seal elements, welds, etc. prior to deployment in an environment. In such an example, one or more units of the electric submersible pump can include internal space or spaces that include dielectric oil where such internal space or spaces may optionally be hermetically sealed (e.g., in an effort to avoid intrusion of a leakage fluid). As an example, during deployment, an electric submersible pump may pass into an aqueous environment (e.g., consider deployment in a subsea surface environment). In such an example, a fluidics system may be operational to control flow of aqueous fluid that may leak into one or more internal spaces where contamination of dielectric oil may occur.

[0083] As an example, an electric submersible pump can include a protector (e.g., a protector unit) that acts to equalize pressure in a motor (e.g., a motor unit) and that provides a reservoir of dielectric oil (e.g., motor oil). A protector and a motor can include a housing or housings that define spaces therewithin in which dielectric oil may be disposed. In such an example, a protector space can be in fluid communication with a motor space, for example, for flow of dielectric oil, pressure balancing of dielectric oil, etc. A fluidics system may act to control flow of leakage fluid to reduce contamination of such dielectric oil.

[0084] As an example, a method can include measuring, calculating and installing a series of shims to establish appropriate spacing between interconnecting drive shafts of various units of an electric submersible pump, for example, such that components properly transmit thrust. In such an example, the method can include assembling components and units, splicing-in and sealing an electrical power cable (or cables), and filling a motor and protector with dielectric oil (e.g., to replenish dielectric fluid that may have been lost during assembly). In such an example, the connection and oil-filling of one or more protectors can involve a plurality of operations that may be relatively time-consuming (e.g., for an ESP technician and/or rig crew).

[0085] As an example, one or more units of an electric submersible pump may be configured prior to shipping to a site in a manner where risk is reduced as to having to perform filling or replenishing dielectric oil at the site (e.g., consider one or more particular types shipping caps such as compensating diaphragm caps, etc.). In such an example, one or more spaces may be filled (e.g., under factory conditions, etc.) with the appropriate amount of dielectric oil, the appropriate type of dielectric oil, etc.

[0086] As an example, during assembly, an inadvertent action or actions may cause one or more of dielectric oil to become contaminated, flange and/or housing sealing surfaces to be damaged or O-rings to be pinched or cut. Contamination of dielectric oil can, for example, reduce risk of electrical and/or bearing failure.

Performing assembly actions for a single pump system may take of the order of ten hours in the field. Where assembly and/or deployment may cause one or more issues, remediation can be costly in terms of time and expense (e.g., including possible down-time as to a production and/or an injection schedule). Established procedures aim to ensure proper operation over a system's intended life. As an example, a fluidics system may act to mitigate one or more issues that may arise during assembly, deployment and/or operation, which, in turn, may help to avoid failure, improper operation, a shortened system life, etc.

[0087] As an example, a dielectric oil can be substantially non-conductive, for example, to reduce risk of inappropriate conduction between various components within a motor unit. As an example, dielectric oil may be a relatively low viscosity oil. As an example, a dielectric oil may be silicone-based, include fluorinated

hydrocarbons, etc.

[0088] Some examples of dielectric oils include silicone oils (e.g., polymerized siloxanes) and transformer oils such as, for example, particular types of mineral oil. As an example, a mineral oil can be a by-product of distillation of petroleum to produce gasoline and other petroleum based products from crude oil. For example, a mineral oil may be a relatively transparent and relatively colorless oil that includes alkanes (e.g., about 15 to about 40 carbons) and cyclic paraffins. As an example, a mineral oil may have a density of the order of about 1 g/cm³ or less (e.g., about 0.9 g/cm³ or less). As such, a dielectric oil can be "lighter" than water. As an example, a dielectric oil can be natural ester based (NEB) (e.g., consider vegetable seed oils). As an example, a dielectric oil may be a polyalphaolefin (PAO) synthetic oil. As an example, dielectric oil may be a perfluoropolyether oil (PFPE) oil. As an example, a dielectric oil may be substantially hydrophobic (e.g., immiscible with water). As an example, dielectric oil can be of a relatively high dielectric strength, for example, of the order of about 25 kV. As an example, dielectric oil may act as a "secondary" electrical insulation, for example, dielectric oil may act to insulate one or more of motor windings, terminals and leads. As an example, dielectric oil can provide lubrication and act as insulation. As an example, dielectric oil may be a mixture of oils.

[0089] As an example, dielectric oil may be referred to as dielectric lubricant as it can provide lubrication to one or more components (e.g., one or more moving components). As an example, dielectric oil may act to reduce risk of moisture (e.g., water) contacting one or more polymeric or other materials that may be at risk of hydrolytic attack/degradation (e.g., consider a polyimide insulation, etc.). [0090] As an example, a motor unit can undergo one or more drying processes (e.g., electrical self-heating, application of a vacuum, etc.) to help ensure that water vapor is diminished before introducing dielectric oil. By diminishing water content, risk of corona formation and subsequent electrical breakdown under load can be reduced.

[0091] Fig. 1 1 shows an example of the ESP system 200 as including one or more features of a system 1 101 , which may be a fluidics system that can include one or more components or features internal to an ESP. As shown, the ESP system 200 may include the ESP 201 with a rotating shaft 219 driven by an electric motor 215 or an ESP 1 102 with a reciprocating shaft 1 104 driven by an electric motor (e.g., linear permanent magnet motor, etc.); noting that the shaft 1 104 may be part of the motor (e.g., include one or more permanent magnets). As shown, the system 1 101 may include one or more of circuitry 11 10, sensor(s) 1120, valve(s) 1 130, pump(s) 1 140 and one or more other features 1 150. As an example, a feature may be internal, external and/or internal and external to a housing of the ESP 201 or the ESP 1 102.

[0092] An electric submersible pump (ESP) can include a shaft that includes an axis; a pump mechanism operatively coupled to the shaft; an electric motor that drives the shaft and that includes an electric motor housing that defines at least a portion of a dielectric oil chamber; and a fluidics system that controls flow of well fluid within the electric motor housing to reduce contamination of the dielectric oil. In such an example, the fluidics system can include an interface and a recessed groove that receives well fluid that passes into the electric motor housing via the interface, for example, where a passage exists that is in fluid communication with the recessed groove.

[0093] As an example, a fluidics system can include one or more of a valve, a sensor and a pump. As an example, a sensor may be a water sensor.

[0094] As an example, an electric submersible pump can include a protector housing that defines at least a portion of a dielectric oil chamber, for example, where the dielectric oil chamber of the protector is in fluid communication with a dielectric oil chamber of an electric motor. As an example, a fluidics system can control flow of well fluid within a protector housing to reduce contamination of dielectric oil.

As an example, a method can include operating an electric submersible pump (ESP); sensing internal well fluid within a portion of the electrical submersible pump (ESP) that includes dielectric oil; and actuating at least one component within the electrical submersible pump (ESP) to control flow of at least a portion of the internal well fluid. In such an example, actuating can include one or more of actuating a valve, actuating a pump, actuating a valve and a pump. As an example, operating an ESP can include pumping well fluid.

[0095] A fluidics system of an electric submersible pump can include a fluid sensor that senses leakage fluid; a controller that includes an interface operatively coupled to the fluid sensor; and a component actuatable by the controller based at least in part on leakage fluid sensed by the fluid sensor. In such an example, a fluid sensor that senses leakage fluid may sense such fluid directly and/or indirectly. For example, a sensor that senses one or more properties of dielectric oil may sense a change in one or more properties of the dielectric oil, which can infer that leakage fluid is present (e.g., contaminating the dielectric oil). As an example, a property may be a dielectric property (e.g., conductivity, etc.). As an example, a property may be clarity (e.g., transmission of light, etc.). As an example, a leakage fluid can include well fluid, which may include water.

[0096] As an example, a fluidics system can include one or more of a valve and a pump as controllable components. As an example, a fluidics system can include one or more recesses, passages, etc. within a unit, a component, etc. of an ESP.

[0097] As an example, a fluidics system can include one or more supplies of power. As an example, a fluidics system can include an interface that is operatively coupled to a wye point of a multiphase electric motor. For example, consider a power supply interface that receives power via a wye point of a multiphase electric motor.

[0098] As an example, one or more methods described herein may include associated computer-readable storage media (CRM) blocks. Such blocks can include instructions suitable for execution by one or more processors (or cores) to instruct a computing device or system to perform one or more actions. As an example, a computer-readable storage medium may be a storage device that is not a carrier wave (e.g., a non-transitory storage medium that is not a carrier wave).

[0099] Fig. 12 shows components of a computing system 1200 and a networked system 1210. The system 1200 includes one or more processors 1202, memory and/or storage components 1204, one or more input and/or output devices 1206 and a bus 1208. According to an embodiment, instructions may be stored in one or more computer-readable media (e.g., memory/storage components 1204). Such instructions may be read by one or more processors (e.g., the processor(s) 1202) via a communication bus (e.g., the bus 1208), which may be wired or wireless. The one or more processors may execute such instructions to implement (wholly or in part) one or more attributes (e.g., as part of a method). A user may view output from and interact with a process via an I/O device (e.g., the device 1206). According to an embodiment, a computer-readable medium may be a storage component such as a physical memory storage device, for example, a chip, a chip on a package, a memory card, etc.

[00100] According to an embodiment, components may be distributed, such as in the network system 1210. The network system 1210 includes components 1222- 1 , 1222-2, 1222-3, . . ., 1222-N. For example, the components 1222-1 may include the processor(s) 1202 while the component(s) 1222-3 may include memory accessible by the processor(s) 1202. Further, the component(s) 1202-2 may include an I/O device for display and optionally interaction with a method. The network may be or include the Internet, an intranet, a cellular network, a satellite network, etc. Conclusion

[00101 ] Although only a few examples have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the examples. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims. In the claims, means- plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures. It is the express intention of the applicant not to invoke 35 U.S.C. § 112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the words "means for" together with an associated function.

Claims

CLAIMS What is claimed is:

1. An electric submersible pump (ESP) comprising:

a shaft that comprises an axis;

a pump mechanism operatively coupled to the shaft;

an electric motor that drives the shaft and that comprises an electric motor housing that defines at least a portion of a dielectric oil chamber; and

a fluidics system that controls flow of well fluid within the electric motor housing to reduce contamination of the dielectric oil.

2. The ESP of claim 1 wherein the fluidics system comprises an interface and a recessed groove that receives well fluid that passes into the electric motor housing via the interface.

3. The ESP of claim 2 comprising a passage that is in fluid communication with the recessed groove.

4. The ESP of claim 1 wherein the fluidics system comprises a valve.

5. The ESP of claim 1 wherein the fluidics system comprises a sensor.

6. The ESP of claim 5 wherein the sensor comprises a water sensor.

7. The ESP of claim 1 wherein the fluidics system comprises a pump.

8. The ESP of claim 1 comprising a protector that comprises a protector housing that defines at least a portion of a dielectric oil chamber.

9. The ESP of claim 8 wherein the dielectric oil chamber of the protector is in fluid communication with the dielectric oil chamber of the electric motor.

10. The ESP of claim 8 wherein the fluidics system controls flow of well fluid within the protector housing to reduce contamination of the dielectric oil.

1 1. A method comprising:

operating an electric submersible pump (ESP);

sensing internal well fluid within a portion of the electrical submersible pump (ESP) that comprises dielectric oil; and

actuating at least one component within the electrical submersible pump (ESP) to control flow of at least a portion of the internal well fluid.

12. The method of claim 1 1 wherein the actuating comprises actuating a valve.

13. The method of claim 1 1 wherein the actuating comprises actuating a pump.

14. The method of claim 1 1 wherein the actuating comprises actuating a valve and a pump.

15. The method of claim 1 1 wherein the operating comprises pumping well fluid.

16. A fluidics system of an electric submersible pump, the fluidics system comprising:

a fluid sensor that senses leakage fluid;

a controller that comprises an interface operatively coupled to the fluid sensor; and

a component actuatable by the controller based at least in part on leakage fluid sensed by the fluid sensor.

17. The fluidics system of claim 16 wherein the component comprises a valve.

18. The fluidics system of claim 16 wherein the component comprises a pump.

19. The fluidics system of claim 16 comprising a power supply interface that receives power via a wye point of a multiphase electric motor. The fluidics system of claim 16 wherein the leakage fluid comprises well fluid.