BACKGROUND

This disclosure is related to the field of electrically operated submersible well pump (ESP) systems deployed under live well conditions. More specifically, the disclosure relates to accessories that can be used with such ESP systems to enable setting and unsetting of an inflatable packer mechanism to hydraulically isolate the discharge of a pump on the ESP system from the intake of the pump.

U.S. Patent No. 10,036,210 issued to Maclean et al. discloses a method for deploying a pump (e.g., electric submersible pump or“ESP”) system in a wellbore. The disclosed method includes coupling the ESP system to one end of a tubing encapsulated cable. The tubing encapsulated cable is extended into a wellbore drilled through a subsurface fluid producing formation. The tubing encapsulated cable has an outer tube extending substantially continuously from the end thereof connected to the ESP system to a surface end of the cable. The outer tube is made from material, e.g., steel, selected to exclude fluid in the wellbore from an interior of the outer tube. The tubing encapsulated cable includes at least one electrical conductor disposed inside the outer tube, wherein a rated load current of the at least one electrical conductor is selected such that substantially continuous electrical current drawn by the electrical load device exceeds the rated current of the at least one insulated electrical conductor.

When using methods such as those disclosed in the‘210 patent, it may be desirable to use an inflatable annular seal (packer) to hydraulically close an annular space between the ESP system and the wellbore tubular in which the ESP system is ultimately disposed, e.g., a production tubing or wellbore casing. To use inflatable annular seals with deployment systems known in the art would require the use of an additional deployment cable or tubing and apparatus to inflate and deflate the inflatable annular seal. It is desirable to have apparatus to enable operation of such inflatable annular seals that can be deployed with the ESP system on a tubing encapsulated cable.

SUMMARY

One aspect of the present disclosure relates to an apparatus for deploying a pump system in a wellbore tubular, which includes an inflatable annular seal disposed on an exterior of a pump system housing. The inflatable annular seal defines a first flow path and a second flow path in a wellbore tubular when the inflatable annular seal is inflated. A pump is disposed within the pump system housing and has a first port and a second port. A first pressure actuated valve is operable to direct discharge from the first port of the pump into an inflation line fluidly coupled to the inflatable annular seal. The first pressure actuated valve is operable to stop flow between the pump and the inflation line when a first operating pressure is obtained. A second pressure actuated valve is operable to direct discharge from first port of the pump to open a first pressure release valve to release pressure from the inflatable annular seal when a second operating pressure is obtained. The second operating pressure is greater than the first operating pressure. The apparatus includes valves operable to cause the pump to move fluid from the first flow path to the second flow path when operation of the pump is reversed to cause flow to discharge from the second port to the second flow path.

The valves may be operable to cause the pump to move fluid from the first flow path to the second flow path comprise check valves.

The first pressure release valve may comprise a pilot operated check valve.

Some examples may further comprise a second pressure release valve fluidly connected between the inflatable annular seal and the first flow path, the second pressure release valve comprising a valve operable to open by application of a predetermined tension.

The pump may comprise a progressive cavity pump.

Some examples may further comprise an electric motor to rotate the pump.

Fluid flow of the pump may be reversible by reversing rotation of the pump.

At least one of the first pressure actuated valve, the second pressure actuated valve and the valves operable to cause the pump to move fluid from the first flow path to the second flow path may be disposed in a housing made at least partially by (e.g., part or fully by) additive manufacturing (three dimensional printing). A method for deploying and operating a pump in a wellbore according to another aspect of the disclosure includes moving a pump system to a selected depth in a wellbore tubular. A pump in the pump system is operated in a first direction to discharge wellbore fluid into an inflatable annular seal disposed on an exterior of a pump housing in the pump system to inflate the first inflatable annular seal. The pump is operated in a second direction to discharge fluid in the wellbore tubular to the surface. Operation of the pump is resumed in the first direction to open a valve to release fluid pressure in the inflatable annular seal. The pump system is then moved from the selected depth.

Resuming operating the pump in the second direction may continue until an operating pressure of a pressure release valve is obtained.

Some examples may further comprise applying tension on the pump system to cause operation of an unloader valve to release the fluid pressure in the annular seal.

Operating the pump may comprise rotating an electric motor.

Other aspects and advantages will be apparent from the description and claims that follow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows schematically an example embodiment of an electrical submersible pump (ESP) system deployed in a wellbore using an electrical cable such as a tubing encapsulated cable.

FIG. 2 shows schematically an example embodiment of hydraulic system components and connections for the ESP system shown in FIG. 1.

DETAILED DESCRIPTION OF THE DRAWINGS

An example embodiment of a cable-deployed, e.g., tubing encapsulated cable- deployed, ESP system is shown in FIG. 1. The ESP system 10 may comprise, within a segmented or unitary housing 13, a drivetrain 16 having, for example, an electric motor and gearbox used to rotate a pump 20, such as a progressive cavity pump or centrifugal pump. The term“housing” as used herein is intended to mean any structure capable of containing and/or retaining in position certain components of an ESP system as explained herein. The pump 20 may be operated reversibly, that is, operated to have respective fluid ports act as suction and discharge ports or the opposite, depending, e.g., on the direction of pump rotation. One of such port(s), shown at 18, may be directed to or in fluid communication with a first port on the pump 20, and such port(s) 18 may be in fluid communication with an annular space 11 between the ESP system 10 and a wellbore tubular 12, such as a production tubing or casing. The port(s) 18 may be disposed above an annular seal as will be explained further below. The ESP system 10 may be conveyed within the wellbore tubular 12 using a cable 14, such as tubing encapsulated electrical cable (TEC), although deployment on TEC is not a limitation on the scope of the present disclosure; other embodiments may use, for example, armoured electrical cable, coiled tubing or jointed tubing. The cable 14 may be extended or retracted using a device such as a winch (not shown) to locate the ESP system 10 at a selected axial position (depth) in a well.

The ESP system 10 may further comprise a sequence valve sub 22, which may be disposed between the pump 20 and a flow bypass check valve sub 24. A shear operated pressure unloader valve 26 may be disposed between the flow bypass check valve sub 24 and an inflatable annular seal 30 such as a packer. An inflatable bladder 30A may act as the sealing element of the annular seal 30 and may be disposed outside of a flow tube 38 and interior of the tubular 12 such that inflation of the bladder 30A seals the space 11 between the flow tube 38 and the tubular 12. The flow tube 38 may be in fluid communication with the second port (see FIG. 2) of the pump 20 through valves in the flow bypass check valve sub 24. When inflated, the bladder 30A may also limit axial movement of the ESP system 10 during pumping operation. A pressure relief valve 28, set to open at a selected pressure, may be provided to prevent over inflation of the bladder 30A. An inflation/deflation fluid line 36 may extend from the sequence valve sub 22 to the bladder 30A to provide a path for fluid under pressure to inflate the bladder 30A and a fluid vent to enable deflation of the bladder 30A. A drain line 34 may be provided to enable venting pressure from valves in the sequence valve sub 22. Operation of the foregoing components will be explained in more detail with reference to FIG. 2.

In operating the ESP system 10 shown in FIG. 1 , the cable 14 may be extended until the ESP system 10 is disposed at a selected depth in the tubular 12. This may be referred to as “running in hole” (RIH). Referring to FIG. 2, wherein hydraulic components of the ESP system (10 in FIG. 1) are shown, an operating sequence for the ESP system (10 in FIG. 1) may begin by inflating the annular seal 30. The pump 20 is started such that fluid is moved from a first port 20A (acting as the pump inlet) to a second port 20B (acting as the pump outlet or discharge). The first port 20A is in fluid communication with the port(s) (18 in FIG. 1) on the ESP system (10 in FIG. 1) above the annular seal 30 in FIG. 1 as previously explained. A pressure actuated valve, A, in the sequence valve sub (22 in FIG. 1 and shown as an outline box in FIG. 2) is initially configured, that is, in its unactuated state, so that fluid can flow between valve ports 2A and 3A. Fluid flow from the pump 20 is also directed to a control port 4A on the pressure actuated valve A. Fluid flows from the pump 20 into the bladder 30A of the annular seal 30 though a check valve 32. The check valve and a pilot operated check valve 33 stop fluid from leaving the bladder 30A. Pressure may be measured by a sensor or gauge 35 to enable determining when the bladder 30A is fully inflated. A check valve 24A in the bypass check valve sub (24 in FIG. 1) also prevents flow of fluid from the pump 20 from being vented. The pressure relief valve 28 will open if the inflation pressure becomes excessive, that is, exceeds the set point pressure of the pressure relief valve 28. Pumping fluid into the bladder 30A may continue until a predetermined inflation pressure is obtained. Such predetermined inflation pressure may be about the same as the actuation pressure of the pressure actuated valve A, which when actuated, stops flow between ports 2A and 3A. The pump 20 may then be stopped. As explained above, fluid flow out of the bladder 30A is stopped by check valves 32 and 33.

In some embodiments, the sequence valve sub 22, and in some embodiments, the flow bypass check valve sub 24 may be made by 3-dimensional printing (additive manufacturing). The respective valves disposed in each such sub 22, 24 may also be disposed in such 3-dimensionally printed sub. Such manufacturing may reduce the complexity of the finished sub(s), reduce cost and facilitate making the sub(s) in a housing readily able to fit within the confines of the ESP system (10 in FIG. 1).

After the annular seal 30 is fully inflated, deployment of the ESP system (10 in FIG. 1) may be tested, e.g., by upward pull on the cable (14 in FIG. 1) to a predetermined tension to confirm engagement of the packer with the tubular (12 in FIG. 1). The pump 20 may then be operated to pump fluid from the well to surface for fluid production purposes. To perform such pumping, the direction of rotation of the pump 20 may be reversed, such that the second port 20B acts as the pump inlet and the first port 20A acts as the pump discharge. In such operation, fluid is drawn into the pump 20 through the flow tube 38 and through check valve 24B, and is discharged through the ESP port(s) 18. Because flow through the pressure actuated valve A between ports 3A and 2A is stopped by the previously described operation of the pressure actuated valve A, and because in its unactuated state pressure actuated valve B closes flow at port 4B, all discharge from the pump 20 is directed to port(s) 18. Pumping the well may continue for any chosen time interval(s). Any pressure on the back side of pilot operated check valve 33 may be vented to the drain line 34 between ports 3B and 2B in the pressure actuated valve B.

When well pumping is no longer needed at a particular depth in a well, pumping may then be stopped to remove the ESP system (10 in FIG. 1) or to move the ESP system (10 in FIG. 1) to a different depth in the well. The ESP system (10 in FIG. 1) may be moved as follows. Pumping may be resumed in the (first) direction used to inflate the annular seal 30. Because the annular seal 30 is already fully inflated at that time, and because the pressure actuated valve A is closed to flow across its ports 3A and 2A, pressure at a control point (shown fluid-connected by a dotted line connection to port 4B) of the pressure actuated valve B will increase with such pumping. The actuation pressure of pressure actuated valve B may be higher than the actuation pressure of pressure actuated valve A. When the pressure reaches a predetermined operating pressure at the control point, pressure actuated valve B actuates to enable flow between port 4B and port 3B. Such flow is then directed to the pilot operated check valve 33 to open the pilot operated check valve. Such pressure to operate the pilot operated check valve 33 is higher than the pressure exerted on the bladder side of the pilot operated check valve 33 because the operating pressure of pressure actuated valve B is higher than the inflation pressure (and the actuation pressure of valve A). Pressure in the bladder 30A may then vent to the drain line 34, thereby allowing the bladder 30A to deflate.

In the event any of the components described above fails such that the deflation sequence cannot be performed, it may be possible to deflate the annular seal 30 by releasing the unloader valve 26. Such release may be performed, for example, by applying (upward) tension on the cable (14 in FIG. 1) to an amount selected to release a locking mechanism, e.g., shear pins, in the unloader valve 26, thereby allowing the unloader valve 26 to open and to vent fluid pressure from the packer 30 into the tubular (12 in FIG. 1). After the annular seal 30 is deflated, the ESP system (10 in FIG. 1) may be moved along the well to another selected position or removed entirely from the well. If desired, the entire sequence described above may be repeated as many times as desired.

The foregoing sequence of actions is summarized in TABLE 1 below. TABLE 1

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.