Patent Application
20200263524
This disclosure relates to zero footprint electronic submersible pumps for oil and gas applications.
Electronic submersible pumps (ESPs) are used in the oil and gas industry as aids for fluid production from wells. A design of a well is typically based on an expected use of an ESP over an entire life of the well. An ESP is placed in a well at a pre-determined depth, depending on an expected grade of oil and presence of water within the well. If the ESP is deployed and/or retrieved on a deployment cable without using a rig, a receptacle that is specifically designed for the ESP is permanently installed within the well at a pre-determined, fixed location during construction of the well, which accordingly determines a single, fixed location of the ESP within the well. The ESP can be attached to the receptacle for installation within the well and detached from the receptacle for replacement once the ESP fails. The receptacle includes control and electrical lines that run to the surface of the well and that are used to control and power the ESP. The receptacle is a costly piece of equipment such that the well, ESP, and receptacle are designed for long-term deployment of an ESP. Such receptacles are prone to failure and typically have a narrow inner diameter that can limit well intervention activities during the life of a well.
In other examples, an artificial nitrogen lifting process is used to aid fluid production from a well. If a well does not flow naturally during a well cleanup operation, a coiled tubing unit can be rigged up and ran into the well for nitrogen lifting of the well. For example, nitrogen can displace fluid in the well to reduce the hydrostatic head, thereby assisting fluid flow out of the well. Coiled tubing is run deep inside of the production tubing (for example, without exiting the production tubing), and nitrogen is pumped into the well to displace fluid from the well. Once the well is flowing, the coiled tubing is pulled out of the well to allow the cleanup operation to resume. The cleanup operation ends once all of the fluid flowing from the well is oil. Deploying nitrogen to the well via the coiled tubing is costly, requires a large equipment footprint, and adds time to the well cleanup operation. Handling the coiled tubing and pressurized nitrogen also introduces safety risks at the well.
This disclosure relates to an electronic submersible pump (ESP) that is deployable to a desired depth within a well to remove fluids from the well as part of a well cleanup operation. The ESP (for example, a downhole pump) is a mobile assembly that is repositionable within the well as necessitated by changing conditions within the well such that the ESP can provide temporary flowback assistance at a varying depth within the well. The ESP includes a pump motor for pumping fluids out of the well, a connection feature to which the deployment cable can attach, and an inflatable packer for securing the ESP to an inner wall surface of a production tubing at a desired depth within the well. The ESP also includes an electrical line for powering the ESP and optionally includes a control line for transmitting data between the ESP and a surface of the well.
In one aspect, a method of removing fluid from a well using a downhole pump includes deploying the downhole pump to a vertical position within a production tubing disposed in the well, securing the downhole pump to the production tubing at the vertical position, powering a motor of the downhole pump with an electrical line of the downhole pump that extends from a surface of the well and that terminates at a profile of the downhole pump, and activating the motor to pump fluid out of the well.
Embodiments may provide one or more of the following features.
In some embodiments, securing the downhole pump to the production tubing includes inflating a packer of the downhole pump to seal the packer against an inner surface of the production tubing at the vertical position.
In some embodiments, the vertical position is a first vertical position, and the method further includes deflating the packer, moving the downhole pump to a second vertical position that is different from the first vertical position, and re-inflating the packer to seal the packer against the inner surface of the production tubing at the second vertical position.
In some embodiments, the method further includes determining that the well is substantially clean, deflating the packer to release the downhole pump from the production tubing, and withdrawing the downhole pump from the well.
In some embodiments, the electrical line is integrated with a deployment cable on which the downhole pump is deployed.
In some embodiments, the electrical line is a separate component from a deployment cable on which the downhole pump is deployed.
In some embodiments, the method further includes collecting production data from the motor with a control line of the downhole pump that extends from the surface of the well and that terminates at the profile of the downhole pump.
In some embodiments, the control line is integrated with a deployment cable on which the downhole pump is deployed.
In some embodiments, the control line is a separate component from a deployment cable on which the downhole pump is deployed.
In some embodiments, the method further includes removing the fluid from the well using the downhole pump without attaching the downhole pump to a pump receptacle within the production tubing.
In some embodiments, the method further includes removing the fluid from the well using the downhole pump without installing a permanent pump receptacle within the production tubing.
In another aspect, a downhole pump for removing fluid from a well includes a motor for pumping fluids out of the well, an electrical line coupled to the motor for powering the motor, the electrical line extending from a surface of the well and terminating at a profile of the downhole pump, and an inflatable packer coupled to the motor for securing the downhole pump to a production tubing within the well at a vertical position.
Embodiments may provide one or more of the following features.
In some embodiments, the inflatable packer is configured to seal against an inner surface of the production tubing.
In some embodiments, the electrical line is integrated with a deployment cable on which the downhole pump is deployable.
In some embodiments, the electrical line is a separate component from a deployment cable on which the downhole pump is deployable.
In some embodiments, the downhole pump further includes a control line coupled to the motor for collecting production data from the motor.
In some embodiments, the control line extends from the surface of the well and terminates at the profile of the downhole pump.
In some embodiments, the control line is integrated with a deployment cable on which the downhole pump is deployable.
In some embodiments, the control line is a separate component from a deployment cable on which the downhole pump is deployable.
In some embodiments, the downhole pump is configured to be installed in the production tubing without being assembled with a pump receptacle.
The details of one or more embodiments are set forth in the accompanying drawings and description. Other features, aspects, and advantages of the embodiments will become apparent from the description, drawings, and claims.
The ESP 100 includes a motor 102 (for example, a pump motor) for pumping fluids out of the well 101, a connection head 104 to which the deployment cable can be attached, a packer 106 for securing the ESP 100 to an inner wall surface of the production tubing 105 at the desired depth, and a shaft 108 that connects the motor 102 to the packer 106. The packer 106 is a radially expandable component that can be inflated to seal against the inner wall surface of the production tubing 105. (In
In some embodiments, the electrical and control lines 110, 112 of the ESP 100 may be integrated with the deployment cable on which the ESP 100 is deployed (for example, initially deployed or subsequently shifted) in the well 101. In such cases, the control line 112 can advantageously provide real-time production data during while the ESP 100 is deployed. Example production data parameters that may be informative or useful during deployment include intake pressure, fluid temperature, and motor temperature.
In some embodiments, the electrical and control lines 110, 112 are not integrated with the deployment cable and may be easily connected to other components of the ESP 100 (for example, the connection head 104 or the motor 102) after the ESP 100 is positioned at a desired location (for example, a desired depth) within the well 101, as shown in
In some embodiments, an ESP that is otherwise substantially similar in construction and function to the ESP 100 may not include a control line 112 at all. Although pump readings may not be provided in such cases, functionality of the ESP may be determined from the electrical line 110 and from a flow rate of fluid flowing from the well in which the ESP is deployed.
The ESP 100 typically has a length (excluding a length of the electrical and control lines 110, 112) of about 10 meters (m) to about 37 m and a diameter (excluding a fully inflated diameter of the packer 106) of about 0.08 m to about 0.1 m. The motor 102 typically operates in a range of about 7 liters per second (L/s) to about 17 L/s. The motor 102, the connection head 104, and the shaft 108 are typically made of one or more of carbon steel with coating, nickel alloys, and ni-resist. The packer 106 is typically made of rubber (for example, tetrafluoroethylene propylene rubber or hydrogenated nitrile butadiene rubber).
During a well cleanup operation, a well is opened up and allowed to flow naturally. If the well does not flow naturally, the ESP 100 can be used to perform a well cleanup operation. The ESP 100 flows a well relatively quickly (for example, as compared to nitrogen lifting), as the ESP 100 does not introduce nitrogen (for example, which is conventionally used in lifting a well) into a well. Rather, the well can begin to flow as soon as the ESP 100 is deployed and switched on. The cleanup operation ends once substantially all of the fluid flowing from the well is oil. Furthermore, the ESP 100 advantageously has a smaller, easier to handle footprint that can be relatively quickly run in a well (for example, over a duration of about 8 hours (h) to about 12 h). In contrast, the coil tubing for nitrogen lifting is costly, bulky, and therefore requires a long time to rig up. Usage of the ESP 100 also enhances rig safety, as the ESP 100 can be stopped at any time to halt fluid flow from a well, whereas unloading a well using nitrogen lifting requires pulling of the coil tubing out of the well after pumping killing fluid in the well to halt fluid flow from the well.
Additionally, because the ESP 100 includes electrical and control lines 110, 112 that are integral with the ESP 100, usage of the ESP 100 does not require installation of a permanent receptacle that includes delicate power and control lines, as do conventional ESPs. Deploying such a receptacle in a well requires a significant amount of time (for example, about 8 h to about 12 h) for slowly running the delicate lines in the well. In contrast, the ESP 100 is a zero footprint assembly that does not require installation of a permanent footprint (for example, a permanent receptacle) in the well 101, saving a significant amount of operational time. The electrical and control lines 110, 112 of the ESP 100 terminate vertically at a profile of the ESP 100 (for example, at a component body, housing, or frame of the ESP 100, such as just below the motor 102) as opposed to extending outside of a profile of the ESP 100 to a surrounding receptacle. That is, the ESP 100 is movable to provide temporary flowback assistance at an optimal location (for example, a vertical position) where needed in the well 101, which is not possible with use of conventional ESPs that are designed for fixed depth positioning of an ESP within a well.
Since the ESP 100 does not require docking to a permanent receptacle in a well, a design of the well may be changed in various ways in the future for enhancing production from the well. For example, the well may be converted to a configuration for a permanent receptacle and ESP at a future time without making changes to a lower portion of the production tubing, if desired. Furthermore, usage of the ESP 100 eliminates the need for a workover rig at a well for changing a permanent receptacle or maintaining it.
While the ESP 100 has been described and illustrated as including a motor 102 that is separate from the connection head 104, in some embodiments, an ESP includes a connection feature that is integral with a motor body. For example,
In the example illustration of
While the above-discussed ESPs 100, 200 have been described and illustrated as including certain dimensions, sizes, shapes, arrangements, and materials, in some embodiments, an ESP that is otherwise substantially similar in construction and function to either of the ESPs 100, 200 may include one or more different dimensions, sizes, shapes, arrangements, and materials.
Other embodiments are also within the scope of the following claims.
