Density gas separation appartus for electric submersible pumps

A system includes an electric submersible pump (ESP) configured for pumping fluid through a flow path. An autonomous inflow control device (AICD) is included in fluid communication with the flow path to separate one of gas or liquid out of the flow path. A method includes producing liquid from a wellbore using an electric submersible pump (ESP) in the wellbore. The method includes bypassing gas from a headspace the wellbore using an autonomous inflow control device (AICD) to prevent gas locking the ESP.

COSS-REFERENCE TO RELATED APPLICATIONS

This is a national stage application under 35 U.S.C. § 371 claiming priority to International Patent Application No. PCT/US2019/061738 filed Nov. 15, 2019 which is incorporated by reference herein in its entirety.

BACKGROUND

The present disclosure relates generally to devices for use in controlling fluid flow. More specifically, but not by way of limitation, this disclosure relates to density-based fluid flow control devices.

2. Description of Related Art

Production tubing and other equipment can be installed in a wellbore of a well system (e.g., an oil or gas well) for communicating fluid in the wellbore to the well surface. The resulting fluid at the well surface is referred to as production fluid. Production fluid can include a mix of different fluid components, such as oil, water, and gas, and the ratio of the fluid components in the production fluid can change over time. This can make it challenging for a well operator to control which types of fluid components are produced from the wellbore. For example, it can be challenging for a well operator to produce mostly oil from the wellbore, while reducing or eliminating the production of gas or water from the wellbore.

The conventional techniques have been considered satisfactory for their intended purpose. However, there is an ever present need for improved fluid flow control devices. This disclosure provides a solution for this need.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made to the drawings wherein like reference numerals identify similar structural features or aspects of the subject disclosure. For purposes of explanation and illustration, and not limitation, a partial view of an embodiment of a system in accordance with the disclosure is shown inFIG.1and is designated generally by reference character100. Other embodiments of systems in accordance with the disclosure, or aspects thereof, are provided inFIGS.2-3, as will be described. The systems and methods described herein can be used for density based gas separation for electric submerged pumps (ESPs).

The system100includes an electric submersible pump (ESP)102configured for pumping fluid through a flow path104. An autonomous inflow control device (AICD)106is included in fluid communication with the flow path104to facilitate the separation one of gas or liquid out of the flow path104by at least partially restricting one of gas or liquid flow in the flow path104. The flow path104and ESP can be in a wellbore108, wherein the ESP102and flow path104are connected in fluid communication to drive flow of production fluids110, e.g., liquids110, from a formation112in which the wellbore108is formed, to a surface114of the wellbore108. The ESP102has a pump inlet116in the flow path104. A dip tube118extending from the pump inlet116downward to an inlet120of the dip tube118that is below a liquid level122in the wellbore108.

The wellbore108includes a headspace124above the liquid level122and below the pump inlet116. The ACID106can be positioned in the headspace124. An inlet126of the AICD106below an outlet128of the AICD106. The AICD106can be configured to vent gas from the headspace124to the surface114through a bypass stream130that bypasses the ESP102, and to inhibit liquids entering the bypass stream130. This can help to prevent gas locking the ESP102.

The ESP102includes a discharge outlet132in the flow path104downstream of the inlet116of the ESP102. The AICD106is in the flow path104upstream of the inlet116of the ESP. However, it is also contemplated that in addition to or in lieu of the AICD106upstream of the inlet116of the ESP, an AICD106can be included in the flow path104downstream of the outlet132of the ESP, e.g. with the purpose of removing gas, dropping the pressure for gas relieve, and/or reducing risk of gas locking the ESP102with pressurized gas above the ESP102. The ESP102can include one or multiple stages134connected together in series in the flow path104. It is also contemplated that in addition to or in lieu of multiple stages134, multiple ESPs102can be connected in series in the flow path104. The AICD106can be positioned in the flow path104in series between the two stages134or ESPs102, e.g., in the positions136indicated inFIG.1. Thus one or more AICDs106can be included in any or all of the positions in series upstream, downstream, or between the stages134or between ESPs102(if multiple ESPs102are used). Those skilled in the art will readily appreciate that while three stages134(or individual ESPs102) are shown inFIG.1, any suitable number of stages134, ESPs102, and AICDs106can be used without departing from the scope of this disclosure.

The AICD106rotates at the same or a different speed from the ESP102, as indicated by the rotation arrow137, about a rotation axis of the AICD106which is aligned parallel to the wellbore axis A. For example, the ESP102can include a rotary shaft138, wherein the AICD106is mechanically connected to the rotary shaft138to drive rotation of the AICD106by power of the ESP102at the same speed as the ESP102. Optionally a gearbox140can mechanically connect the rotary shaft138to the AICD106, wherein the gearbox140is configured to drive the AICD106at a higher RPM rate than the rotary shaft138of the ESP102. It is also contemplated that the AICD106can be rotationally independent of the ESP102. For example, the AICD106can include a set of rotary fins142, shown inFIG.2, exposed to the flow path104, labeled inFIG.1, for driving rotation of the AICD106in response to fluid flow through the flow path104.

With continued reference toFIG.2, the AICD106can include a housing144with at least one float member146. InFIGS.2-3, there are three float members146. Each float member146is arranged there a respective valve opening148in the housing144. Each float member146is hingedly connected to the housing144so as to occlude the respective valve opening148or unocclude the valve opening148based on fluid density of fluid flowing through the AICD106under buoyancy from centrifugal forces from rotation of the float members146and fluids within the AICD106. In this manner, in the absence of gas within the housing144of the AICD106, the float members146impede liquid flow through the valve opening, and unocclude the valve openings148in the presence of gas within the housing144to vent gas through the valve openings148and thereby divert the gas from the flow path104(ofFIG.1) out the bypass130(ofFIG.1) and avoid gas lock interruption of the ESP102. The AICD106can thus be rotated to generate centrifugal forces for discriminating between liquid and gas. Additional information about AICDs is provided in International Patent Application Publication No. WO2019/135814, the contents of which are incorporated by reference herein in their entirety.

Those skilled in the art having the benefit of this disclosure will readily appreciate that the scope of this disclosure is not limited to any specific type of AICD or other device that restricts the flow of a lower viscosity fluid and has attenuated restriction to the flow of a higher viscosity fluid. For example, the term AICD can includes devices that have a fluidic vortex such as are provided by Halliburton of Houston, Tex. under the trade name Equiflow® Autonomous Inflow Control Device.

Accordingly, as set forth above, the embodiments disclosed herein may be implemented in a number of ways. For example, in general, in one aspect, the disclosed embodiments relate to a system. The system includes an electric submersible pump (ESP) configured for pumping fluid through a flow path. An autonomous inflow control device (AICD) is included in fluid communication with the flow path configured to at least partially restrict one of gas or liquid flow in the flow path.

In general, in another aspect, a method includes producing liquid from a wellbore using an electric submersible pump (ESP) in the wellbore. The method includes bypassing gas from a headspace the wellbore using an autonomous inflow control devices (AICD) to prevent gas locking the ESP.

In another aspect, the ESP can include an inlet in fluid communication with the flow path, and an outlet in the flow path downstream of the inlet, wherein the AICD is in the flow path upstream of the inlet. It is also contemplated that the ESP can include an inlet in fluid communication with the flow path, and a discharge outlet in the flow path downstream of the inlet, wherein the AICD is in the flow path downstream of the outlet to remove gas or drop the pressure for gas relief.

In another aspect, the ESP can include at least two stages connected together in series in the flow path, wherein the AICD is in the flow path in series between the two stages. The AICD can be a first AICD, a second AICD can be connected in series in the flow path with the two stages, wherein the first AICD is in series between the two stages, and wherein the second AICD is in series upstream or downstream of the two stages.

In another aspect, the ESP can be a first ESP, and a second ESP can be connected in series with the first ESP, wherein the AICD is connected in series between the first and second ESPs. The AICD can be a first AICD and a second AICD can be connected in series in the flow path with the first and second ESPs, wherein the first AICD is in series between the first and second ESPs, and wherein the second AICD is in series upstream or downstream of the first and second ESPs.

In another aspect, the AICD can rotate at the same or a different speed from the ESP. The ESP can include a rotary shaft, wherein the AICD is mechanically connected to the rotary shaft to drive rotation of the AICD by power of the ESP. A gearbox can mechanically connect the rotary shaft to the AICD, wherein the gearbox is configured to drive the AICD at a higher RPM rate than the rotary shaft of the ESP. It is also contemplated that the AICD can be rotationally independent of the ESP. The AICD can include a set of rotary fins exposed to the flow path for driving rotation of the AICD in response to fluid flow through the flow path.

In another aspect, the AICD can include at least one float member and a valve opening, wherein the float member is connected to occlude the valve opening or unocclude the valve opening based on fluid density of fluid flowing through the AICD under centrifugal forces from rotation of the float member within the AICD. The float member can be configured to occlude the valve opening in the absence of gas within a housing of the AICD, impeding liquid flow through the valve opening, and to unocclude the valve opening in the presence of gas within the housing to vent gas through the valve opening and thereby divert the gas from the flow path and avoid gas lock interruption of the ESP.

In another aspect, the flow path can be in a wellbore, wherein the ESP and flow path are connected to drive flow of production fluids from a formation in which the wellbore is formed, to a surface of the wellbore. The wellbore can include the ESP therein, with a pump inlet in the flow path, and with a dip tube extending from the pump inlet downward to an inlet of the dip tube below a liquid level in the wellbore.

In another aspect, the wellbore can include a headspace above the liquid level and below the pump inlet. The ACID can be positioned in the headspace, with an inlet of the AICD below an outlet of the AICD. The AICD can be configured to vent gas from the headspace to the surface through a bypass stream that bypasses the ESP, and to inhibit liquids entering the bypass stream. The AICD can include at least one float within a housing of the AICD, wherein the at least one float is configured to rotate about a rotation axis of the AICD which is aligned parallel to the wellbore. The AICD can be rotated to generate centrifugal forces for discriminating between liquid and gas.

The methods and systems of the present disclosure, as described above and shown in the drawings, provide for density based gas separation for electric submerged pumps (ESPs). While the apparatus and methods of the subject disclosure have been shown and described with reference to preferred embodiments, those skilled in the art will readily appreciate that changes and/or modifications may be made thereto without departing from the scope of the subject disclosure.