Integrity cap and method of integrity testing

Abstract

An integrity cap (116) is disclosed. The integrity cap (116) is configured for integrity testing of at least one of a powering cable, a motor of an electric submersible pump (ESP) (112) and a downhole sensor. The integrity cap (116) is attachable to at least a part of a wellhead penetrator (114) electrically connected via at least one electrically conductive cable (118) to the ESP (112). The integrity cap (116) comprises at least one connector element (122) for electrically connecting to at least one phase of the electrically conductive cable (118) of the wellhead penetrator (114); and at least one electronics unit (124) for monitoring the integrity of one or more of the powering cable, the motor and the downhole sensor of the ESP (112) by performing at least one integrity measurement via the at least one connector element (122). Further disclosed are a method of integrity testing and a wellhead penetrator kit (110).

Description

[0001] Integrity Cap and Method of Integrity Testing

[0002] Technical Field

[0003] The invention relates to an integrity cap for integrity testing of at least one of a powering cable, a motor of an electric submersible pump (ESP) and a downhole sensor. Further, the invention relates to a method of integrity testing of one or more of a powering cable, a motor of an ESP and a downhole sensor. The invention further relates to a wellhead penetrator kit. The devices and methods according to the present invention may be applied in the general field of earth fluid extraction, when one or more ESPs are used, e.g. to increase fluid production. Specifically, the invention may be used in ESP supported oil and / or water production from oil or water wells. Other applications, however, are also feasible.

[0004] Background art

[0005] The use of ESPs, typically also referred to as submersible centrifugal pumps, is common in earth fluid extraction processes, such as in the oil industry, to produce or increase production from oil or water wells. These pumps typically consist of various electrical components prone to be damaged during installation of the pump in the underground well, i.e. during downhole installation. Thus, regular monitoring of the condition of the pump’s electrical components is generally performed manually by specially trained personnel, e.g. by an onsite technician, during the installation process. However, specially trained personnel is typically expensive and availability is generally short due to hard and taxing working conditions. Furthermore, during the installation of the pump, once the upper end of the pump’s electrical cable, e.g. the part of the downhole electrical cable arranged on the penetrator end, is connected to the tubing hanger, typically, a special operation called the landing operation of the pump installation starts during which the tubing hanger to which the ESP is connected is placed in the wellhead, inside a Blowout Preventer (BOP). During this landing operation, typically, the on-site technician has no access to monitor the condition of the pump’s electrical components, e.g. by performing electrical insulation checks, due to difficult physical accessibility as well as potential security risks. Thus, typically, the condition of the pump’s electrical components is not monitored during this final landing operation. However, in case damages occur during the landing operation, these damages usually are not detected before completion of the landing operation. Thus, typically dismantling of the BOP is required before the technician may have access for monitoring the condition of the pump’s electrical components. Then, in case a downhole electrical cable damage is confirmed, usually the BOP requires re-assembly, and to investigate the damage location, the hanger typically must be pulled out. All in all, this situation usually results in a significant loss of time and money.

[0006] Problem to be solved

[0007] It is therefore desirable to provide devices and methods, which address the above mentioned shortcomings. Specifically, an integrity cap and a method for integrity testing shall be proposed, as well as a wellhead penetrator kit, which allows for safe, economic and regular ESP integrity testing, specifically during at least one wellhead landing operation, e.g. during landing of a tubing hanger of a wellhead.

[0008] Summary

[0009] This problem is addressed by an integrity cap for integrity testing of at least one of a powering cable, a motor of an electric submersible pump (ESP) and a downhole sensor, by a method of integrity testing of one or more of a powering cable, a motor of an electric submersible pump (ESP) and a downhole sensor, as well as by a wellhead penetrator kit with the features of the independent claims. Advantageous embodiments which might be realized in an isolated fashion or in any arbitrary combinations are listed in the dependent claims as well as throughout the specification.

[0010] As used in the following, the terms “have”, “comprise” or “include” or any arbitrary grammatical variations thereof are used in a non-exclusive way. Thus, these terms may both refer to a situation in which, besides the feature introduced by these terms, no further features are present in the entity described in this context and to a situation in which one or more further features are present. As an example, the expressions “A has B”, “A comprises B” and “A includes B” may both refer to a situation in which, besides B, no other element is present in A (i.e. a situation in which A solely and exclusively consists of B) and to a situation in which, besides B, one or more further elements are present in entity A, such as element C, elements C and D or even further elements.

[0011] Further, it shall be noted that the terms “at least one”, “one or more” or similar expressions indicating that a feature or element may be present once or more than once typically will be used only once when introducing the respective feature or element. In the following, in most cases, when referring to the respective feature or element, the expressions “at least one” or “one or more” will not be repeated, non-withstanding the fact that the respective feature or element may be present once or more than once.

[0012] Further, as used in the following, the terms "preferably", "more preferably", "particularly", "more particularly", "specifically", "more specifically" or similar terms are used in conjunction with optional features, without restricting alternative possibilities. Thus, features introduced by these terms are optional features and are not intended to restrict the scope of the claims in any way. The invention may, as the skilled person will recognize, be performed by using alternative features. Similarly, features introduced by "in an embodiment of the invention" or similar expressions are intended to be optional features, without any restriction regarding alternative embodiments of the invention, without any restrictions regarding the scope of the invention and without any restriction regarding the possibility of combining the features introduced in such way with other optional or non-optional features of the invention.

[0013] In a first aspect of the present invention, an integrity cap for integrity testing of at least one of a powering cable, a motor of an electric submersible pump (ESP) and a downhole sensor, such as a sensor of the ESP, is disclosed. The integrity cap may specifically be configured for integrity testing of at least one of a powering cable of the ESP, a motor of the ESP and a downhole sensor, such as a sensor of the ESP, during at least one wellhead landing operation, e.g. during landing of a tubing hanger of a wellhead. The integrity cap is attachable to at least a part of a wellhead penetrator, which is electrically connected via at least one electrically conductive cable to the ESP.

[0014] The term “integrity testing” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a procedure of monitoring and / or checking functionality and / or faultlessness of an arbitrary device and / or system. Specifically, the integrity testing of a system may be or may comprise an examination of the system’s functional health, such as a check-up and / or investigation of predefined vital and / or relevant functions of the system.

[0015] The term “electric submersible pump” or “ESP” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a system comprising at least one pump and configured for extracting, e.g. by pumping, one or more fluids from at least one well. In particular, the ESP may be a system comprising an electrically driven pump for pumping oil and / or water from an underground oil and / or water well towards a surface, e.g. from below earth surface towards the earth surface.

[0016] The integrity cap comprises at least one connector element for electrically connecting to at least one phase of the electrically conductive cable of the wellhead penetrator. Further, the integrity cap comprises at least one electronics unit for monitoring the integrity of one or more of the powering cable, specifically the powering cable of the ESP, the motor, specifically the motor of the ESP, and the downhole sensor of the ESP by performing at least one integrity measurement via the at least one connector element.

[0017] The term “connector element” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an arbitrary object and / or element configured for establishing an electrical connection with at least one other object and / or element. In particular, the connector element may have a shape such as to physically contact one phase of the electrically conductive cable of the wellhead, thereby establishing an electrical connection to the phase, such as a connection via which electrical energy is transmittable.

[0018] The term “phase” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to a wire of an electric cable. In particular, the phase may be or may comprise a live conductor of the cable, such as a current-carrying conductor. Specifically, the phase may refer to one of three line conductors in a cable used for transmitting three-phase electric power. The term “electronics unit” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an arbitrary functional element configured for performing and / or controlling at least one measurement as well as analyzing and / or processing the generated measurement data. The electronics unit may specifically comprise at least one processor. The processor may in particular be configured for controlling the integrity measurement and for analyzing the measurement data, such as the measurement results.

[0019] The term “integrity measurement” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an electrical measurement, generating at least one measurement signal, such as at least one electronic signal, e.g. at least one voltage and / or current signal, from which the desired information on a status and / or functionality of the entity whose integrity is to be monitored is determined and / or determinable, i.e. by the electronics unit. In particular, the integrity measurement may be or may comprise a process of monitoring a condition, status and / or functionality of one or more of the ESP’s electrical cable, the ESP’s motor and the at least one ESP sensor. As an example, integrity measurements may be or may comprise one or more of an electrical insulation measurement and a phase resistance balance measurement. Other measurements suitable for evaluating the ESP’s integrity may also be possible and may also be referred to as integrity measurements.

[0020] As an example, the downhole sensor, specifically the ESP sensor, may be one or more of a pressure sensor, a temperature sensor, and a vibration sensor.

[0021] The integrity cap may comprise at least one evaluation device, preferably as part of the electronics unit, for evaluating the integrity of one or more of the powering cable, the motor and the sensor of the ESP. In particular, the evaluation device may be configured for deriving at least one item of integrity information from at least one measurement result provided by the electronics unit.

[0022] Furthermore, the integrity cap may comprise at least one reporting device configured for reporting on at least one measurement result provided by the electronics unit, specifically on the item of integrity information derived by the evaluation device. In particular, the measurement result may be one or both of quantifying or qualifying the integrity of one or more of the powering cable, the motor and the sensor of the ESP. As an example, the reporting device for reporting the measurement result may comprise one or more of a loud speaker, a light element, a data transmitter, such as for transmitting the measurement result, e.g. via Bluetooth and / or Wi-Fi, to an operator and / or controller device. Such an operator and / or controller device may be a separate device from the integrity cap, but may be part of a wellhead penetrator kit as outlined in further detail below.

[0023] The integrity cap may further comprise at least one mounting element. In particular, the integrity cap, by the mounting element, may be attachable to the wellhead penetrator. Specifically, the integrity cap may be attachable to the wellhead penetrator by the mounting element via and / or through at least one form fit connection. Thus, at least one form fit connection may be established between the mounting element and the wellhead penetrator, thereby for example attaching the integrity cap to the wellhead penetrator. The form fit connection may specifically be at least one connection selected from the group consisting of a screw connection and a snap fit connection.

[0024] The integrity cap may further comprise at least one housing, such as an explosion proof housing. Specifically, the explosion proof housing may be rated “Ex ia” and / or “Ex ib” according to EU Directive 2014 / 34ZEU.

[0025] As an example, the housing may configured for, when the integrity cap is attached to the wellhead penetrator, shielding the surface side of the wellhead penetrator from environmental debris, e.g. from one or more of moisture, dirt, dust and the like. In particular, the connector element and the electronics unit, and preferably the evaluation device, may be arranged within the housing. Specifically, the connector element and the electronics unit, and preferably the evaluation device, may be fully enclosed within the housing. Thus, the housing, besides shielding the surface side of the wellhead penetrator from environmental debris may also shield the connector element and the electronics unit and optionally also the evaluation device from environmental debris.

[0026] The integrity cap may further comprise at least one electric power source, such as a battery, for powering the electronics unit. In particular, the electric power source, e.g. the battery, may be arranged within the housing. Specifically, the battery may be fully enclosed within the housing.

[0027] The housing may, for example, be at least partially made of at least one material selected from the group consisting of plastic, such as thermoplastic, thermosetting resin plastic or rubber, and metal, such as aluminum or steel. Specifically, the material may be one or more of a plastic material and a metal material. Thus, the housing may at least partially be made of one or more of thermoplastic, thermosetting resin plastic, rubber, aluminum and steel.

[0028] The integrity cap may further comprise at least one magnetically activatable switch, wherein the switch may be arranged within the housing. In particular, the magnetically activatable switch may be turned on by using a magnet, such as a permanent magnet or an electromagnet. Additionally, the switch may further be magnetically deactivatable. Thus, the magnet besides being activatable by using the magnet may also be deactivatable by using the magnet. For example, the magnetically activatable switch may be switchable, i.e. turned on and / or off, by using the permanent magnet and / or the electromagnet. Furthermore, the switch may be fully enclosed within the housing. Thus, the switch, while being enclosed within the housing, may be switchable from outside the housing by using magnetic force, e.g. exerted by the magnet, such as by the permanent magnet and / or the electromagnet.

[0029] The switch may control a power connection of the integrity cap. Thus, specifically in case the switch is in a deactivated state, an electric connection to the electric power source may be interrupted. When the switch is in an activated however, the electric connection to the electric power source may be established. Thus, as an example, the integrity cap may be turned on and / or off by the at least one magnetic force. Specifically a power supply to the integrity cap’s parts may be activated and / or turned off by the magnetic force, e.g. by using an external magnet, such as a permanent magnet and / or an electromagnet.

[0030] The switch may be configured for only functioning when the housing is in a closed state. Thus, as an example, only when the housing is closed, the magnetic switch may establish a power connection when activated by the magnetic force.

[0031] The integrity cap may comprise at least two, specifically three, connector elements, wherein each connector element may be configured for connecting to a different phase of the electrically conductive cable of the wellhead penetrator. The at least one connector element may specifically comprise at least one of a male or female mating element configured for being plugged into or onto the phase of the electrically conductive cable of the wellhead penetrator. As an example, the at least one connector element may at least partially be made of at least one metal selected from the group consisting of copper, aluminum, and steel.

[0032] Specifically, the integrity cap may comprise at least one ground connector, connected to a ground. As an example, the housing may function as the ground. Thus, for example, the electronics unit may be configured for performing the at least one integrity measurement by using the connector elements’ connection to one or more of the different phases and / or, specifically additionally, by using the ground connector, such as a connection to the housing.

[0033] The electronics unit may be configured for one or both of continuously performing the integrity measurement and performing the integrity measurement within predefined intervals. Thus, as an example, the electronics unit may be configured for performing the integrity measurement continuously, i.e. throughout at least the duration of the landing operation. Additionally or alternatively, the electronics unit may be configured for performing the integrity measurement within a distance interval depending on a distance the wellhead pene- trator is lowered, e.g. depending on a progress of the landing operation. Further, additionally or alternatively, the electronics unit may be configured for performing the integrity measurement within a predefined time interval, such as depending on a time interval, on a time that has passed since the last measurement or since an initial start of the measurement. Thus, for example, the electronics unit may be configured for performing the integrity measurement every 30 seconds. As an example, the initial start of the measurement may be one or more of the switch activating the power connection of the integrity cap, the press of a start button, the integrity cap being mounted to the wellhead penetrator by form fitting the mounting element to the wellhead penetrator, or a similar predefined event.

[0034] The integrity measurement may be one or more of a resistance measurement and a signal measurement. As an example, the integrity measurement may be a resistance measurement between the at least one phase of the electrically conductive cable and the ground. Additionally or alternatively, the integrity measurement may be a resistance measurement between at least two phases of the electrically conductive cable. Further, additionally or alternatively, the integrity measurement may be a signal measurement measuring whether or not a downhole sensor signal is received. Thus, for example the integrity measurement may be or may comprise measuring whether or not one or more of a pressure signal is received from the pressure sensor, a temperature signal is received from the temperature sensor, and a vibration signal is received from the vibration sensor.

[0035] For example, the electronics unit may be configured for measuring an insulation, e.g. the insulation of the powering cable, during the landing operation of the hanger and optionally even longer, for example as long as completion of the ESP installation takes, i.e. until the ESP is ready for use. Specifically, the insulation measurement may comprise measuring a phase to ground, particularly a phase to earth, status. As a further example, the electronics unit may, additionally or alternatively, be configured for measuring a functionality of the powering cable, i.e. fortransporting current, and / or a continuity of the motor, e.g. of the ESP motor, e.g. by measuring a phase to phase status, i.e. a status between at least two different phases of the electrically conductive cable of the ESP. As yet a further example, the electronics unit may, additionally or alternatively, be configured for measuring a functionality of the downhole sensors, e.g. by measuring the availability of sensor signals from one or more of the downhole sensors.

[0036] As an example, the integrity cap may have to be attached to the wellhead penetrator before the wellhead landing operation is started. In particular, the process of attaching of the integrity cap to the wellhead penetrator may also be referred to as a process of installing the integrity cap. Specifically, the installation of the integrity cap may have to be completed, e.g. on the rig floor, such as on an oil or water rig platform, before landing of the tubing hanger of the wellhead.

[0037] The integrity cap may specifically be a single use, disposable system. Thus, the integrity cap may be disposed of after use.

[0038] When removing the integrity cap, the power may have to be turned off, e.g. by the switch, before disconnecting, i.e. detaching, the integrity cap from the wellhead penetrator. As an example, in case the form fit connection of the mounting element is a screw connection, the disconnecting may be performed by unscrewing and / or unthreading the integrity cap from the wellhead penetrator.

[0039] In a further aspect of the present invention, a method of integrity testing of one or more of a powering cable, a motor of an electric submersible pump (ESP) and a downhole sensor, such as a sensor of the ESP, specifically during at least one wellhead landing operation, e.g. during landing of a tubing hanger of a wellhead, is disclosed. The method comprises the following steps, which may be performed in the given order. Still, a different order is possible. The method may comprise additional steps, which are not mentioned. It is further possible to perform one or more or all of the method steps repeatedly. Further, two or more of the method steps may be performed simultaneously or in a timely overlapping fashion.

[0040] The method comprises the following steps: a) providing at least one integrity cap comprising: at least one connector element, and at least one electronics unit; b) providing at least one ESP and at least one wellhead penetrator electrically connected to the ESP via at least one electrically conductive cable; c) attaching the integrity cap to at least a part of the wellhead penetrator, such that the connector element is connected to at least one phase of the electrically conductive cable of the wellhead penetrator; d) monitoring the integrity of one or more of the powering cable, the motor and the downhole sensor of the ESP by performing at least one integrity measurement, by the electronics unit, via the at least one connector element.

[0041] The method may further comprise the following step: e) deriving, by at least one evaluation device of the integrity cap, at least one item of integrity information from at least one measurement result provided by the electronics unit.

[0042] Further, the method may comprise the following step: f) reporting on the at least one measurement result, specifically on the item of integrity information, by at least one reporting device of the integrity cap, wherein the measurement result is one or both of quantifying or qualifying the integrity of one or more of the powering cable, the motor and the sensor of the ESP.

[0043] As an example, step f) may further comprise providing a warning, if the item of integrity information indicates that the integrity of one or more of the powering cable, the motor of the ESP, and the downhole sensor, e.g. the sensor of the ESP, is compromised, for example not functioning the way it should be. Specifically, the warning may be provided by one or more of the following: sounding an alarm via at least one loud speaker of the reporting device, turning a light element of the reporting device on or off, e.g. in a predefined pattern, changing a light color of a light element of the reporting device, e.g. changing from a green color to a red color, sending an error message via a data transmitter of the reporting device, e.g. via Bluetooth and / or Wi-Fi, to an operator and / or controller device.

[0044] Further, the method may comprise the following step: g) monitoring an operating status of the integrity cap comprising providing a signal if a power supply issue occurs, for example in case the integrity cap’s electric power source is damaged or running low. Specifically, step d) of the method may comprise one or both of continuously performing the integrity measurement and performing the integrity measurement in predefined intervals. Thus, as an example, the method may comprise, e.g. by using the electronics unit, performing the integrity measurement continuously, i.e. throughout at least the duration of the landing operation. Additionally or alternatively, the method, e.g. by using the electronics unit, may comprise performing the integrity measurement within a distance interval depending on a distance the wellhead penetrator is lowered, e.g. depending on a progress of the landing operation. Further, additionally or alternatively, the method, e.g. by using the electronics unit, may comprise performing the integrity measurement within a predefined time interval, such as depending on a time interval. Thus, for example, the method, e.g. by using the electronics unit, may comprise performing the integrity measurement every 30 seconds.

[0045] In particular, the integrity cap of step a) of the method may be an integrity cap as described above or as further described below. Thus, for possible definitions and options, reference may be made to the description of the integrity cap as given above or as further described below.

[0046] In yet a further aspect of the present invention, a wellhead penetrator kit is disclosed. The wellhead penetrator kit comprises an ESP, a wellhead penetrator electrically connected to the ESP via at least one electrically conductive cable and an integrity cap as described above or as further described below. Thus, for possible definitions and options, again, reference may be made to the description of the integrity cap as given above or as further described below.

[0047] The proposed integrity cap, method of integrity testing and penetrator kit provide a large number of advantages over the prior art. In particular, the proposed devices and methods allow for an economic, safe and reliable monitoring of the integrity of an ESP, such as of one or more of the ESP powering cable, the ESP motor and the one or more ESP downhole sensors.

[0048] Specifically, the integrity cap, by being a self-powered electronic device that, once connected to an ESP, e.g. to the ESP system at the top of the wellhead penetrator, may be able to reliably and continuously measure and report on the ESP electrical system integrity status. In particular, without any required interference from specially trained technicians or other personnel. Thus, the provided devices and methods may allow for an economic and safe monitoring of the integrity of an ESP, such as of one or more of the ESP powering cable, the ESP motor and the one or more ESP downhole sensors. Furthermore, the proposed devices and methods may indicate an occurrence of one or more damages immediately and automatically, thereby allowing for a fast and reliable monitoring of the integrity of an ESP, such as of one or more of the ESP powering cable, the ESP motor and the one or more ESP downhole sensors.

[0049] Summarizing and without excluding further possible embodiments, the following embodiments may be envisaged:

[0050] Embodiment 1. An integrity cap for integrity testing of at least one of a powering cable, a motor of an electric submersible pump (ESP) and a downhole sensor, such as a sensor of the ESP, specifically during at least one wellhead landing operation, e.g. during landing of a tubing hanger of a wellhead, the integrity cap being attachable to at least a part of a wellhead penetrator electrically connected via at least one electrically conductive cable to the ESP, the integrity cap comprising: at least one connector element for electrically connecting to at least one phase of the electrically conductive cable of the wellhead penetrator; at least one electronics unit for monitoring the integrity of one or more of the powering cable, the motor and the downhole sensor of the ESP by performing at least one integrity measurement via the at least one connector element.

[0051] Embodiment 2. The integrity cap according to the preceding embodiment, wherein the integrity cap further comprises: at least one evaluation device, preferably as part of the electronics unit, for evaluating the integrity of one or more of the powering cable, the motor and the sensor of the ESP, wherein the evaluation device is configured for deriving at least one item of integrity information from at least one measurement result provided by the electronics unit.

[0052] Embodiment 3. The integrity cap according to any one of the preceding embodiments, wherein the integrity cap further comprises: at least one reporting device configured for reporting on at least one measurement result provided by the electronics unit, specifically on the item of integrity information derived by the evaluation device, wherein the measurement result is one or both of quantifying or qualifying the integrity of one or more of the powering cable, the motor and the sensor of the ESP. Embodiment 4. The integrity cap according to the preceding embodiment, wherein the reporting device for reporting the measurement result comprises one or more of a loud speaker, a light element, a data transmitter, such as for transmitting the measurement result, e.g. via Bluetooth and / or Wi-Fi, to an operator and / or controller device.

[0053] Embodiment 5. The integrity cap according to any one of the preceding embodiments, wherein the integrity cap further comprises at least one mounting element, wherein the integrity cap by the mounting element is attachable to the wellhead penetrator via at least one form fit connection.

[0054] Embodiment 6. The integrity cap according to the preceding embodiment, wherein the form fit connection is at least one connection selected from the group consisting of a screw connection, a snap fit connection.

[0055] Embodiment 7. The integrity cap according to any one of the preceding embodiments, wherein the integrity cap further comprises at least one explosion proof housing, specifically the housing is rated “Ex ia” and / or “Ex ib” according to EU Directive 2014 / 34ZEU.

[0056] Embodiment 8. The integrity cap according to the preceding embodiment, wherein the housing is configured for, when the integrity cap is attached to the wellhead penetrator, e.g. at least to the part of the wellhead penetrator, shielding the surface side of the wellhead penetrator from environmental debris, e.g. from one or more of moisture, dirt, dust and the like, wherein the connector element and the electronics unit, and preferably the evaluation device, are arranged, specifically enclosed, within the housing.

[0057] Embodiment 9. The integrity cap according to any one of the two preceding embodiments, wherein the integrity cap further comprises at least one electric power source, such as a battery, for powering the electronics unit, wherein the electric power source is arranged, specifically enclosed, within the housing.

[0058] Embodiment 10. The integrity cap according to any one of the three preceding embodiments, wherein the housing is at least partially made of at least one material selected from the group consisting of plastic, such as thermoplastic, thermosetting resin plastic or rubber; and metal, such as aluminum or steel. Embodiment 11. The integrity cap according to any one of the four preceding embodiments, wherein the integrity cap further comprises at least one magnetically activatable switch, wherein the switch is arranged, specifically enclosed, within the housing.

[0059] Embodiment 12. The integrity cap according to the preceding embodiment, wherein the switch is further magnetically deactivatable.

[0060] Embodiment 13. The integrity cap according to any one of the two preceding embodiments, wherein the switch controls a power connection of the integrity cap, wherein specifically in a deactivated state an electric connection to the electric power source is interrupted.

[0061] Embodiment 14. The integrity cap according to any one of the preceding embodiments, wherein the integrity cap comprises at least two, specifically three, connector elements, each configured for connecting to a different phase of the electrically conductive cable of the wellhead penetrator.

[0062] Embodiment 15. The integrity cap according to any one of the preceding embodiments, wherein the at least one connector element comprises at least one of a male or female mating element configured for being plugged into or onto the phase of the electrically conductive cable of the wellhead penetrator.

[0063] Embodiment 16. The integrity cap according to any one of the preceding embodiments, wherein the at least one connector element is at least partially made of at least one metal selected from the group consisting of copper, aluminum, and steel.

[0064] Embodiment 17. The integrity cap according to any one of the preceding embodiments, wherein the downhole sensor is one or more of a pressure sensor, a temperature sensor, and a vibration sensor.

[0065] Embodiment 18. The integrity cap according to any one of the preceding embodiments, wherein the electronics unit is configured for one or both of continuously performing the integrity measurement and performing the integrity measurement within predefined intervals, such as a distance interval depending on a distance the wellhead penetrator is lowered, e.g. depending on a progress of the landing operation, or a time interval depending on a time that has passed since the last measurement, e.g. every 30 seconds. Embodiment 19. The integrity cap according to any one of the preceding embodiments, wherein the integrity measurement is at least one or more of a resistance measurement, specifically a resistance measurement between the at least one phase of the electrically conductive cable and the ground and / or between at least two phases of the electrically conductive cable, a signal measurement, such as measuring whether or not a downhole sensor signal is received, for example a pressure signal from the pressure sensor, a temperature signal from the temperature sensor, a vibration signal from the vibration sensor.

[0066] Embodiment 20. The integrity cap according to any one of the preceding embodiments, wherein the integrity cap is a single use, disposable system.

[0067] Embodiment 21. A method of integrity testing of one or more of a powering cable, a motor of an electric submersible pump (ESP) and a downhole sensor, such as a sensor of the ESP, specifically during at least one wellhead landing operation, e.g. during landing of a tubing hanger of a wellhead, the method comprising: a) providing at least one integrity cap comprising: at least one connector element, and at least one electronics unit; b) providing at least one ESP and at least one wellhead penetrator electrically connected to the ESP via at least one electrically conductive cable; c) attaching the integrity cap to at least a part of the wellhead penetrator, such that the connector element is connected to at least one phase of the electrically conductive cable of the wellhead penetrator; d) monitoring the integrity of one or more of the powering cable, the motor and the downhole sensor of the ESP by performing at least one integrity measurement, by the electronics unit, via the at least one connector element.

[0068] Embodiment 22. The method according to the preceding embodiment, wherein the method further comprises e) deriving, by at least one evaluation device of the integrity cap, at least one item of integrity information from at least one measurement result provided by the electronics unit.

[0069] Embodiment 23. The method according to the preceding method embodiment, wherein the method further comprises f) reporting on the at least one measurement result, specifically on the item of integrity information, by at least one reporting device of the integrity cap, wherein the measurement result is one or both of quantifying or qualifying the integrity of one or more of the powering cable, the motor and the sensor of the ESP.

[0070] Embodiment 24. The method according to the preceding method embodiment, wherein step f) comprises providing a warning, if the item of integrity information indicates that the integrity of one or more of the powering cable, the motor of the ESP, and the downhole sensor, e.g. the sensor of the ESP, is compromised, by one or more of sounding an alarm via at least one loud speaker of the reporting device, turning a light element of the reporting device on or off, e.g. in a predefined pattern, changing a light color of a light element of the reporting device, e.g. changing from a green color to a red color, sending an error message via a data transmitter of the reporting device, e.g. via Bluetooth and / or Wi-Fi, to an operator and / or controller device.

[0071] Embodiment 25. The method according to any one of the preceding method embodiments, wherein the method further comprises g) monitoring an operating status of the integrity cap comprising providing a signal if a power supply issue occurs, for example in case the integrity cap’s electric power source is damaged or running low.

[0072] Embodiment 26. The method according to any one of the preceding method embodiments, wherein step d) comprises one or both of continuously performing the integrity measurement and performing the integrity measurement in predefined intervals, such as a distance interval depending on a distance the wellhead penetrator is lowered, e.g. depending on a progress of the landing operation, or or a time interval depending on a time that has passed since the last measurement, e.g. every 30 seconds.

[0073] Embodiment 27. The method according to any one of the preceding method embodiments, wherein the integrity cap of step a) is an integrity cap according to any one of the preceding embodiments referring to an integrity cap.

[0074] Embodiment 28. A wellhead penetrator kit comprising an ESP, a wellhead penetrator electrically connected to the ESP via at least one electrically conductive cable and an integrity cap according to any one of the preceding embodiments referring to an integrity cap. Short description of the Figures

[0075] Further optional features and embodiments will be disclosed in more detail in the subsequent description of embodiments, preferably in conjunction with the dependent claims. Therein, the respective optional features may be realized in an isolated fashion as well as in any arbitrary feasible combination, as the skilled person will realize. The scope of the invention is not restricted by the preferred embodiments. The embodiments are schematically depicted in the Figures. Therein, identical reference numbers in these Figures refer to identical or functionally comparable elements.

[0076] In the Figures:

[0077] Figure 1 shows a schematic illustration of an embodiment of a wellhead penetrator kit with an embodiment of an integrity cap;

[0078] Figures 2 to 4 show an embodiment of an integrity cap in a perspective view (Figure 2), in a sectional view (Figure 3) and in an exploded view (Figure 4); and

[0079] Figures 5 and 6 show different flow charts of a method of integrity testing.

[0080] Detailed description of the embodiments

[0081] In Figure 1, a schematic illustration of a wellhead penetrator kit 110 comprising an electric submersible pump (ESP) 112, a wellhead penetrator 114 and an integrity cap 116. The wellhead penetrator 114 is electrically connected to the ESP 112 via at least one electrically conductive cable 118. As an example, the wellhead penetrator 114 may comprise of at least two parts, one of which is mechanically fixed to the electrically conductive cable 118 connecting the wellhead penetrator 114 to the ESP 112. Specifically, the wellhead penetrator 114 may be configured to be arranged at least partially below the earth’s surface 119. In particular, the two parts of the wellhead penetrator may be connected to each other by snap fitting the two parts together in a direction as exemplarily indicated by the two arrows in Figure 1. Other means of connecting, for example via a screw connection, are also possible.

[0082] The integrity cap 116 is attachable to at least a part of the wellhead penetrator 114 electrically connected via the at least one electrically conductive cable 118 to the ESP 112. The integrity cap 116 is configured for integrity testing of at least one of a powering cable, e.g. the electrically conductive cable 118, a motor of the ESP 112 and a downhole sensor, such as a sensor of the ESP 112, for example one or more of a pressure sensor, a vibration sensor, a temperature sensor and the like. Specifically, the integrity cap 116 may be configured for integrity testing one or more of the powering cable, the motor of the ESP 112 and the downhole sensor during at least one wellhead landing operation, for example during landing of a tubing hanger 120 of a wellhead as exemplarily illustrated in Figure 1.

[0083] An exemplary embodiment of an integrity cap 116 illustrated in a perspective view in Figure 2, in a sectional view in Figure 3 and in an exploded view in Figure 4. The integrity cap 116 comprises at least one connector element 122 for electrically connecting to at least one phase of the electrically conductive cable 118 of the wellhead penetrator 114. Specifically, the integrity cap 116 may comprise more than one connector element 122, such as for example three connector elements, each configured for connecting to a different phase of the electrically conductive cable 118 of the wellhead penetrator 114. Further, the integrity cap 116 comprises at least one electronics unit 124, such as for example in form of an electronic chip or card, for monitoring the integrity of one or more of the powering cable, the motor and the downhole sensor of the ESP 112, by performing at least one integrity measurement via the at least one connector element 122. In particular, the integrity measurement may be or may comprise at least one electrical measurement from which a deduction may be made regarding one or more of the condition, status and functionality of one or more of the powering cable, e.g. the electrically conductive cable 118, the motor of the ESP 112 and the downhole sensor of the ESP 112.

[0084] The integrity cap 116 may comprise at least one housing 126, such as an explosion proof housing 126. The housing 126 of the integrity cap 116 may specifically be configured for shielding the wellhead penetrator 114 from environmental debris, such as from one or more of moisture, dirt, dust and the like. In particular, the housing 126 may, when the integrity cap 116 is attached to the wellhead penetrator 114, e.g. to the part of the wellhead penetrator 114 which is schematically illustrated in the top part of Figure 1, shield the surface side of the wellhead penetrator 114, e.g. the side of the wellhead penetrator 114 facing the surface 119 of the earth of the wellhead penetrator 114, from environmental debris. The connector element 122 and the electronics unit 124, may be arranged, specifically enclosed, within the housing 126.

[0085] The integrity cap 116 may further comprise at least one evaluation device 128 as part of the electronics unit 124, for evaluating the integrity of one or more of the powering cable, the motor and the sensor of the ESP 112. In particular, the evaluation device 128 may be configured for deriving at least one item of integrity information from at least one measurement result provided by the electronics unit 124.

[0086] The integrity cap 116 may further comprise at least one reporting device 130 configured for reporting on at least one measurement result provided by the electronics unit 124 on the item of integrity information derived by the evaluation device 128. In particular, the reporting device 130 may be or may comprise a data transmitter for transmitting the measurement result, e.g. via Bluetooth and / or Wi-Fi, to an operator and / or to a controller device. Additionally or alternatively, the reporting device 130 may be or may comprise a loudspeaker and / or a light element configured for providing at least one signal, such as a visible and / or audibly detectable signal, according to a status indicated by the item of integrity information. If the one or more of the powering cable, the motor and the sensor are running and / or working as expected, the signal may indicate that for example by showing a green light. Additionally or alternatively, if the integrity of one or more of the powering cable, the motor and the sensor of the ESP 112 is compromised, i.e. if the item of integrity information indicates a fault and / or error in the status, the condition and / or the functionality of one or more of these entities, the signal may be a warning signal, such as a red light or a warning sound.

[0087] The integrity cap 116 may be configured to be mounted to the wellhead penetrator via at least one form fit connection. For this purpose, the integrity cap 116 may comprise at least one mounting element 132. The mounting element 132 may be attachable to the wellhead penetrator 114 via the at least one form fit connection. Thus, the mounting element 132 may be configured for attaching the integrity cap 116 to the wellhead penetrator 114. The form fit connection may for example be a screw connection, as is exemplarily illustrated in Figure 3. However, other form fit connections, such as e.g. via a snap fit connection, are also feasible.

[0088] The housing 126 may particularly comprise more than one part. For example, the housing 126 may be put together and / or be made up of more than one part, e.g. of at least two parts, such as by at least one lid 134 and at least one main body 136. As an example, the mounting element 132 may be one such part of the housing 126. Additionally or alternatively, the mounting element 132 and the housing 126 may be integrally formed, e.g. the housing 126 may at least partially comprise the mounting element 132. The integrity cap 116 may further comprise at least one electric power source, such as a battery 138, for powering the electronics unit 124. As an example, the battery 134 may be arranged, specifically enclosed, within the housing 126 of the integrity cap 116.

[0089] Further, the integrity cap 116 may comprise at least one magnetically activatable switch 140. The switch 140 may specifically be arranged within the housing 126 and may further also be magnetically deactivatable. In particular, the switch may be configured to control a power connection of the integrity cap 116. Thus, specifically in a deactivated state, the switch may interrupt an electric connection of the integrity cap 116 to the electric power source, e.g. between the battery 138 and the electronics unit 124.

[0090] Further, the set-up of the integrity cap 116 may be compartmentalized by the housing 126. For example, the housing 126 may compartmentalize the integrity cap 116, such as by at least partially closing off from each other different partitions, compartments and / or areas of an interior of the integrity cap 116. Specifically, different components of the integrity cap 116 may be arranged in different compartments of the integrity cap’s housing 126. As an example, the battery 138 may be in a different compartment and / or partition of the housing 126 than the electronics unit 124. The connector elements 122 may be arranged in yet another compartment of the integrity cap’s housing 126. However, even if the battery 138 and the electronics unit 124 are arranged in different compartments, they may still be connected by a switchable connection, activatable by the switch 140. The same may be true for the connector elements 122 and the electronics unit 124, which may still be connected, directly or indirectly, by one or more electrical connections even if they are arranged in different compartments and / or partitions of the housing 126. Further, specifically for the purpose of compartmentalizing and / or partitioning, the housing 126 may additionally comprise one or more inlays 142, such as exemplarily illustrated in Figures 3 and 4.

[0091] Figures 5 and 6 show different flow charts of a method of integrity testing of one or more of a powering cable a motor of an electric submersible pump (ESP) 112 and a downhole sensor, such as a sensor of the ESP 112, for example one or more of a pressure sensor, a vibration sensor, a temperature sensor and the like. Specifically, the method may be a method of integrity testing one or more of the powering cable, the motor of the ESP 112 and the downhole sensor during at least one wellhead landing operation, for example during landing of a tubing hanger 120 of a wellhead as exemplarily illustrated in Figure 1. As an example, the method may make use of the integrity cap 116 as described above, e.g. the integrity cap 116 embodiments of which are exemplarily illustrated in Figures 2 to 4. The method comprises the following steps, which may specifically be performed in the given order. Still, a different order may also be possible. It may be possible to perform two or more of the method steps fully or partially simultaneously. It may further be possible to perform one, more than one or even all of the method steps once or repeatedly. The method may comprise additional method steps, which are not listed. The method steps of the method are the following: a) (denoted by reference number 144) providing at least one integrity cap 116 comprising: at least one connector element 122, and at least one electronics unit 124; b) (denoted by reference number 146) providing at least one ESP 112 and at least one wellhead penetrator 114 electrically connected to the ESP 112 via at least one electrically conductive cable 118; c) (denoted by reference number 148) attaching the integrity cap 116 to at least a part of the wellhead penetrator 114, such that the connector element 122 is connected to at least one phase of the electrically conductive cable 118 of the wellhead penetrator 114; d) (denoted by reference number 150) monitoring the integrity of one or more of the powering cable, the motor and the downhole sensor of the ESP by performing at least one integrity measurement, by the electronics unit 124, via the at least one connector element 122.

[0092] As an example, step d) may comprises one or both of continuously performing the integrity measurement and performing the integrity measurement in predefined intervals. The predefined intervals may be or may comprise a distance interval depending on a distance the wellhead penetrator 114 is lowered, e.g. below the surface 119. Thus, for example, the predefined interval may be a distance interval depending on a progress of the landing operation. Additionally or alternatively, the predefined intervals may be or may comprise a time interval, such as depending on a passage of time, e.g. every 30 seconds or any other arbitrary predefined number of seconds.

[0093] Further, the method may comprise one or more of the following steps: e) (denoted by reference number 152) deriving, by at least one evaluation device 128 of the integrity cap 116, at least one item of integrity information from at least one measurement result provided by the electronics unit 124; f) (denoted by reference number 154) reporting on the at least one measurement result, specifically on the item of integrity information, by at least one reporting device 130 of the integrity cap 116, wherein the measurement result is one or both of quantifying or qualifying the integrity of one or more of the powering cable, the motor and the sensor of the ESP 112.

[0094] As an example, step f) may further comprise providing a warning, if the item of integrity information indicates that the integrity of one or more of the powering cable, the motor of the ESP, and the downhole sensor, e.g. the sensor of the ESP, is compromised. Specifically, such as warning may be provided by one or more of the following: sounding an alarm via at least one loud speaker of the reporting device 130, turning a light element of the reporting device 130 on or off, e.g. in a predefined pattern, changing a light color of a light element of the reporting device 130, e.g. changing from a green color to a red color, sending an error message via a data transmitter of the reporting device 130, e.g. via Bluetooth and / or Wi-Fi, to an operator and / or controller device.

[0095] The method may further comprise the following step: g) (denoted by reference number 156) monitoring an operating status of the integrity cap 116 comprising providing a signal if a power supply issue occurs, for example in case the integrity cap’s electric power source is damaged or running low.

[0096] List of reference numbers penetrator kit electric submersible pump (ESP) wellhead penetrator integrity cap electrically conductive cable earth’s surface tubing hanger connector element electronics unit housing evaluation device reporting device mounting element lid main body battery switch inlay step a) step b) step c) step d) step e) step f) step g)

Claims

Claims1. An integrity cap (116) for integrity testing of at least one of a powering cable, a motor of an electric submersible pump (ESP) (112) and a downhole sensor, the integrity cap (116) being attachable to at least a part of a wellhead penetrator (114) electrically connected via at least one electrically conductive cable (118) to the ESP (112), the integrity cap (116) comprising: at least one connector element (122) for electrically connecting to at least one phase of the electrically conductive cable (118) of the wellhead penetrator (114); at least one electronics unit (124) for monitoring the integrity of one or more of the powering cable, the motor and the downhole sensor of the ESP (112) by performing at least one integrity measurement via the at least one connector element (122).

2. The integrity cap (116) according to the preceding claim, wherein the integrity cap (116) further comprises: at least one evaluation device (128) for evaluating the integrity of one or more of the powering cable, the motor and the sensor of the ESP (112), wherein the evaluation device (128) is configured for deriving at least one item of integrity information from at least one measurement result provided by the electronics unit (124).

3. The integrity cap (116) according to any one of the preceding claims, wherein the integrity cap (116) further comprises: at least one reporting device (130) configured for reporting on at least one measurement result provided by the electronics unit (124), wherein the measurement result is one or both of quantifying or qualifying the integrity of one or more of the powering cable, the motor and the sensor of the ESP (112).

4. The integrity cap (116) according to any one of the preceding claims, wherein the integrity cap (116) further comprises at least one mounting element (132), wherein the integrity cap (116) by the mounting element (132) is attachable to the wellhead penetrator (114) via at least one form fit connection, wherein the form fit connection is at least one connection selected from the group consisting of a screw connection and a snap fit connection.

5. The integrity cap (116) according to any one of the preceding claims, wherein the integrity cap (116) further comprises at least one explosion proof housing (126), wherein the housing (126) is configured for, when the integrity cap (116) is attached to the wellhead penetrator (114), shielding the surface side of the wellhead penetrator (114) from environmental debris, wherein the connector element (122) and the electronics unit (124) are arranged within the housing (126).

6. The integrity cap (116) according to the preceding claim, wherein the integrity cap (116) further comprises at least one electric power source, such as a battery (138), for powering the electronics unit (124), wherein the electric power source is arranged within the housing (126).

7. The integrity cap (116) according to any one of the two preceding claims, wherein the integrity cap (116) further comprises at least one magnetically activatable switch (140), wherein the switch (140) is arranged within the housing (126), wherein the switch (140) controls a power connection of the integrity cap (116).

8. The integrity cap (116) according to any one of the preceding claims, wherein the integrity cap (116) comprises at least two connector elements (122), each configured for connecting to a different phase of the electrically conductive cable (118) of the wellhead penetrator (114).

9. The integrity cap (116) according to any one of the preceding claims, wherein the electronics unit (124) is configured for one or both of continuously performing the integrity measurement and performing the integrity measurement within predefined intervals, such as a distance interval or a time interval.

10. The integrity cap (116) according to any one of the preceding claims, wherein the integrity measurement is at least one or more of a resistance measurement and a signal measurement.

11. A method of integrity testing of one or more of a powering cable, a motor of an electric submersible pump (ESP) (112) and a downhole sensor, the method comprising: a) providing at least one integrity cap (116) comprising: at least one connector element (122), andat least one electronics unit (124); b) providing at least one ESP (112) and at least one wellhead penetrator (114) electrically connected to the ESP (112) via at least one electrically conductive cable (H8); c) attaching the integrity cap (116) to at least a part of the wellhead penetrator (114), such that the connector element (122) is connected to at least one phase of the electrically conductive cable (118) of the wellhead penetrator (114); d) monitoring the integrity of one or more of the powering cable, the motor and the downhole sensor of the ESP (112) by performing at least one integrity measurement, by the electronics unit (124), via the at least one connector element (122).

12. The method according to the preceding claim, wherein the method further comprises e) deriving, by at least one evaluation device (128) of the integrity cap (116), at least one item of integrity information from at least one measurement result provided by the electronics unit (124).

13. The method according to the preceding method claim, wherein the method further comprises f) reporting on the at least one measurement result by at least one reporting device (130) of the integrity cap (116), wherein the measurement result is one or both of quantifying or qualifying the integrity of one or more of the powering cable, the motor and the sensor of the ESP (112).

14. The method according to the preceding method claim, wherein step f) comprises providing a warning, if the item of integrity information indicates that the integrity of one or more of the powering cable, the motor of the ESP (112), and the downhole sensor is compromised, by one or more of: sounding an alarm via at least one loud speaker of the reporting device (130), turning a light element of the reporting device (130) on or off, changing a light color of a light element of the reporting device (130), sending an error message via a data transmitter of the reporting device (130) to an operator and / or controller device.

15. A wellhead penetrator kit (110) comprising an ESP (112), a wellhead penetrator (114) electrically connected to the ESP (112) via at least one electrically conductive cable (118) and an integrity cap (116) according to any one of the preceding claims referring to an integrity cap (116).