Patent Application
20250122785
The disclosure relates generally to production of fluid from subterranean reservoirs. More particularly, the disclosure relates to the use of electrical submersible pump assemblies that reduce gas accumulation of the fluid intakes.
Fluids are typically produced from a reservoir in a subterranean formation by drilling a wellbore into the subterranean formation, establishing a flow path between the reservoir and the wellbore, and conveying the fluids from the reservoir through the wellbore to a destination such as to the surface of the earth, to a bed of a body of water such as a lakebed or a seabed, or to a surface of a body of water such as a swamp, a lake, or an ocean (hereafter “surface.”) Fluids produced from a hydrocarbon reservoir may include natural gas, oil, and water. Typically, a production tubing is disposed in the wellbore to carry the fluids to the surface. In some formations, pressure within the rock formation causes the resources to flow naturally from the formation to the surface. One common challenge in producing fluids from a hydrocarbon reservoir through a wellbore is that, in some formations, the pressure in the formation is not adequate to cause the flow against gravity out of the formation to the surface or is not adequate to cause the flow to meet flowrate goals. In such instances, artificial lift technology can be used to add energy to fluid to bring the resources to the surface.
This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.
This disclosure presents, in accordance with one or more embodiments, a method that includes providing an electrical submersible pump assembly (ESP) with a pump, an intake, shroud base flanges, a protector, and a motor. The method includes providing fluid communication between a production tubing and the ESP. The production tubing delivers well fluid containing both gases and liquids from the ESP into a wellhead assembly through an inner bore of the production tubing. The method includes circumscribing the production tubing with a packer assembly downstream of the ESP, then coupling the shroud base flanges to a top surface of an intake base flange. The shroud base flanges are disposed on an intake downhole end of the intake. The shroud base flanges are disposed using a first set of fasteners, a set of inner bolt holes disposed on the shroud base flanges, and a set of protector top bolt holes disposed on a protector top surface of a protector top flange of the protector. The method includes locating a closed end of an inverted shroud between the intake and the protector. The inverted shroud includes a shroud base disposed on the closed end, and an opposite open end that is open toward the packer assembly. The method includes coupling the inverted shroud to the shroud base flanges using a second set of fasteners, a set of outer bolt holes disposed on the shroud base flanges, and a set of shroud base bolt holes disposed on the shroud base. The packer assembly is located uphole of the opposite open end at a distance causing a mixing of a gas pocket with the well fluid to form a combined gas and liquid mixture and directing the combined gas and liquid mixture in a direction toward the intake.
This disclosure presents, in accordance with one or more embodiments, a method that includes providing an electrical submersible pump assembly (ESP) with a pump, an intake that includes an extended intake base flange, a protector, and a motor. The method includes providing fluid communication between a production tubing and the ESP. The production tubing delivers well fluid containing both gases and liquids from the ESP into a wellhead assembly through an inner bore of the production tubing. The method includes circumscribing the production tubing with a packer assembly downstream of the ESP, then locating a closed end of an inverted shroud between the intake and the protector. The inverted shroud includes a shroud base disposed on the closed end, and an opposite open end that is open toward the packer assembly. The method includes coupling the inverted shroud to the extended intake base flange using a set of fasteners, a set of outer bolt holes disposed on the extended intake base flange, and a set of shroud base bolt holes disposed on the shroud base. The packer assembly is located uphole of the opposite open end at a distance causing a mixing of a gas pocket with the well fluid to form a combined gas and liquid mixture and directing the combined gas and liquid mixture in a direction toward the intake.
This disclosure presents, in accordance with one or more embodiments, a method that includes providing an electrical submersible pump assembly (ESP) with a pump, an intake with an integrated shroud base flange, a protector, and a motor. The method includes providing fluid communication between a production tubing and the ESP. The production tubing delivers well fluid containing both gases and liquids from the ESP into a wellhead assembly through an inner bore of the production tubing. The method includes circumscribing the production tubing with a packer assembly downstream of the ESP, then locating an inverted shroud between the intake and the protector. The inverted shroud includes a first set of bolt holes on an inverted shroud downhole end, and an opposite open end that is open toward the packer assembly. The method includes coupling, using a set of fasteners, the first set of bolt holes, and a second set of bolt holes disposed on the integrated shroud base flange, the inverted shroud to the integrated shroud base flange. The packer assembly is located uphole of the opposite open end at a distance causing a mixing of a gas pocket with the well fluid to form a combined gas and liquid mixture and directing the combined gas and liquid mixture in a direction toward the intake.
This disclosure presents, in accordance with one or more embodiments, a system that includes an electrical submersible pump assembly (ESP) with a pump, an intake, shroud base flanges, a protector, and a motor. The system includes production tubing in fluid communication with the ESP with an inner bore sized to deliver well fluid containing both gases and liquids from the ESP to a wellhead assembly. The system includes a packer assembly circumscribing the production tubing downstream of the ESP. The system includes a first set of fasteners, a set of inner bolt holes disposed on the shroud base flanges, and a set of protector top bolt holes disposed on a protector top surface of a protector top flange of the protector. The first set of fasteners is configured to couple the shroud base flanges to a top surface of an intake base flange disposed on an intake downhole end of the intake. The system includes an inverted shroud with a closed end configured to be located between the intake and the protector, an opposite open end that is open towards the packer assembly, and a shroud base disposed on the closed end. The system includes a second set of fasteners configured to couple the inverted shroud to the shroud base flanges using a set of outer bolt holes disposed on the shroud base flanges and a set of base bolt holes disposed on the shroud base. The packer assembly is located uphole of the opposite open end at a distance operable to cause a mixing of a gas pocket with the well fluid to form a combined gas and liquid mixture and to direct the combined gas and liquid mixture in a direction towards the intake.
This disclosure presents, in accordance with one or more embodiments, a system that includes an electrical submersible pump assembly (ESP) with a pump, an intake with an extended intake base flange, a protector, and a motor. The system includes production tubing in fluid communication with the ESP with an inner bore sized to deliver well fluid containing both gases and liquids from the ESP to a wellhead assembly. The system includes a packer assembly circumscribing the production tubing downstream of the ESP. The system includes an inverted shroud with a closed end configured to be located between the intake and the protector, an opposite open end that is open towards the packer assembly, and a shroud base disposed on the closed end. The system includes a set of fasteners configured to couple the inverted shroud to the extended intake base flange using a set of outer bolt holes disposed on the extended intake base flange and a set of base bolt holes disposed on the shroud base. The packer assembly is located uphole of the opposite open end at a distance operable to cause a mixing of a gas pocket with the well fluid to form a combined gas and liquid mixture and to direct the combined gas and liquid mixture in a direction towards the intake.
This disclosure presents, in accordance with one or more embodiments, a system that includes an electrical submersible pump assembly (ESP) with a pump, an intake with an integrated shroud base flange, a protector, and a motor. The system includes production tubing in fluid communication with the ESP with an inner bore sized to deliver well fluid containing both gases and liquids from the ESP to a wellhead assembly. The system includes a packer assembly circumscribing the production tubing downstream of the ESP. The system includes an inverted shroud with a first set of bolt holes on an inverted shroud downhole end and an opposite open end that is open towards the packer assembly. The system includes a set of fasteners configured to couple the inverted shroud to the integrated shroud base flange using the first set of bolt holes and a second set of bolt holes disposed on the integrated shroud base flange. The packer assembly is located uphole of the opposite open end at a distance operable to cause a mixing of a gas pocket with the well fluid to form a combined gas and liquid mixture and to direct the combined gas and liquid mixture in a direction towards the intake.
Other aspects and advantages of the claimed subject matter will be apparent from the following description and the appended claims.
In the following detailed description of embodiments of the disclosure, numerous specific details are set forth in order to provide a more thorough understanding of the disclosure. However, it will be apparent to one of ordinary skill in the art that the disclosure may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description.
Throughout the application, ordinal numbers (e.g., first, second, third, etc.) may be used as an adjective for an element (i.e., any noun in the application). The use of ordinal numbers is not to imply or create any particular ordering of the elements nor to limit any element to being only a single element unless expressly disclosed, such as using the terms “before”, “after”, “single”, and other such terminology. Rather, the use of ordinal numbers is to distinguish between the elements. By way of an example, a first element is distinct from a second element, and the first element may encompass more than one element and succeed (or precede) the second element in an ordering of elements.
Regarding the figures described herein, when using the term “down” the direction is toward or at the bottom of a respective figure and “up” is toward or at the top of the respective figure. “Up” and “down” are oriented relative to a local vertical direction. However, in the oil and gas industry, one or more activities take place in a vertical, substantially vertical, deviated, substantially horizontal, or horizontal well. Therefore, one or more figures may represent an activity in deviated or horizontal wellbore configuration. “Uphole” may refer to objects, units, or processes that are positioned relatively closer to the surface entry in a wellbore than another. “Downhole” may refer to objects, units, or processes that are positioned relatively farther from the surface entry in a wellbore than another. True vertical depth is the vertical distance from a point in the well at a location of interest to a reference point on the surface.
For bringing liquids out of a subterranean wellbore to the surface of the Earth, various techniques such as artificial lift technology may be used. Artificial lift technology may include, for example, a pump and associated components to assist in lifting the fluids up the wellbore. As an example, production tubing associated with the wellbore may include one or more pumps to assist in lifting the fluids up the wellbore. The pump may be electrically operated and located submerged in the fluid at or near the bottom of the well. The pump system may use a surface or seabed power source to drive the submerged pump assembly. Alternatively, power for the pump may be provided at another location downhole in the well, such as a downhole fuel cell. These pump systems so configured are termed electric submersible pump (ESP) systems.
Notably, ESP performance may be impacted by various reservoir characteristics such as, for example, gas-oil ratio, water cut, flowing wellhead pressure (FWHP), well test liquid rate, and pump operating frequency. It is beneficial to be able to adjust parameters to optimize ESP performance. In particular, there exists a need for a method for optimizing the performance of ESPs in real time by recommending the optimum pump control settings to maximize pump operating efficiency and minimize overall power consumption for a determined target well rate.
As such, embodiments disclosed herein present systems and methods that may enable producing a well, reduce the gaseous component of a combined gas and liquid mixture produced from the well, and improve installation of an ESP inverted shroud onto an ESP assembly disposed in the well. The shroud is installed at a wellsite by field personnel. Embodiments disclosed herein may facilitate installation by field personnel with minimal deviation from standard installation procedure. One of the challenges of the installation procedure for the ESP shroud is the attachment of the shroud to an existing ESP with minimal modification to current ESP architecture. A second challenge is the assembly at the wellsite of the relatively long length of the inverted shroud. Embodiments disclosed herein propose a method and a system to resolve these challenges with minimal modifications to the standard installation procedure and to the ESP architecture.
A monitoring sub such as sensor 26 may be included in ESP 14 as an optional element. In the example embodiment of
In accordance with one or more embodiments, pump 18 is adjacent to intake 24, intake 24 is located between pump 18 and protector 20, protector 20 is located between intake 24 and motor 16, and motor 16 is located further within subterranean well 10 than pump 18. Therefore, from top to bottom the elements are ordered: pump 18, intake 24, protector 20, and motor 16.
Well fluid such as well fluid F (e.g., a well fluid 32) is shown entering wellbore 12 from a formation adjacent to the wellbore 12 through perforations 27. Well fluid F for production, flows to opening 29 of intake 24. The cross sectional area through which well fluid F travels from perforations 27 to intake 24 is not reduced to a small diameter bore, thus offering an advantage over other systems such as those that utilize, for example, stingers upstream of intake 24. The lack of reduction of the bore therefore causes no significant increase in the velocity of well fluid F, no significant decrease in the pressure of well fluid F, and reduces the potential for gas breakout versus systems that utilize the stingers upstream of intake 24.
Well fluid F is pressurized by pump 18 and travels up to wellhead assembly 28 at surface 30 through a production tubing 34. Production tubing 34 is in fluid communication with ESP 14. The production tubing has an inner bore (e.g., an inner bore 35) sized to deliver well fluid F from ESP 14 to wellhead assembly 28. ESP 14 is positioned within wellbore 12 so that motor 16 is located downstream, or uphole, of perforations 27 through the outer tubular member 22 so that well fluid F flowing through perforations 27 pass the motor 16 before entering intake 24. This helps to cool motor 16 with well fluid F.
ESP 14 is suspended from, and supported by, production tubing 34. Production tubing 34 is an elongated tubular member that extends within subterranean well 10. Production tubing 34 can be formed of carbon steel material, carbon fiber tube, or other types of corrosion resistance alloys or coatings.
Well fluid F may contain both gases and liquids as it enters intake 24 and both the gases and liquids can be produced to wellhead assembly 28 through production tubing 34 as a combined production fluid. Pump 18 is operable to provide artificial lift to well fluid F that contain a combined gas and liquid mixture and production tubing 34 has an inner bore sized to deliver the combined gas and liquid mixture to wellhead assembly 28.
Well fluid F is produced through production tubing 34. There is no outlet for well fluid within ESP 14 to travel back into wellbore 12, i.e., well fluid F are not produced through the tubing casing annulus 36. Tubing casing annulus 36 is an annular space located between an outer diameter of production tubing 34 and an inner diameter of outer tubular member 22.
Power cable 38 extends through wellbore 12 alongside production tubing 34. Power cable 38 can provide the power required to operate motor 16 of ESP 14. Power cable 38 extends to a packer assembly (e.g., a packer 40) and can be connected to packer with a packer penetrator at the top side of packer. Power cable 38 can then extend between packer and motor 16 with a motor lead extension. The motor lead extension can be connected to a packer penetrator at the bottom side of packer. Power cable 38 can be a suitable power cable for powering an ESP 14, known to those with skill in the art.
Inverted shroud 42 is a generally tubular member that has closed end 44 located between intake 24 and protector 20. Closed end 44 circumscribes ESP 14 and prevents well fluid F from entering within inverted shroud 42 at closed end 44. An opposite open end (e.g., an open end 46) of inverted shroud 42 is open towards the packer assembly. Fluids flowing through perforations 27 therefore travel in a direction towards wellhead assembly 28 (
Well fluid F flowing up the wellbore 12 is therefore made to go through a 180° turn towards intake 24. Due to this turn and the interaction and mixing of well fluid F at and below a bottom surface of packer, any gas pockets keep moving with well fluid F and accumulation of gas under the packer is prevented. If any gases do separate from liquid and begin to gather at the bottom surface of packer, eddies and current of well fluid F will cause such gases to be carried with well fluid F into intake 24. Therefore, the bottom of packer remains free of accumulated gas. The liquid and gas components of well fluid F are well mixed, therefore the liquid phase carries the gas pockets into the intake 24 and pump 18 pressurizes and pumps the combined gas and liquid mixture to the surface as in a conventional method.
Packer is spaced apart from inverted shroud 42 a distance that provides for a mixing of the gases and liquids of well fluid F. Mixing of the combined gas and liquid mixture occurs between packer and inverted shroud 42 before the combined gas and liquid mixture enters the inverted shroud 42. As an example, the open end of inverted shroud 42 can be spaced from packer to allow mixing of the gas and liquid in the well fluid mixture. In an alternate example, the open end of inverted shroud 42 can be spaced a distance from packer to allow mixing of the gas and liquid well fluid.
In an example of operation, production tubing 34 can support ESP 14 and be used to lower ESP 14 into wellbore 12. ESP 14 can be lowered into subterranean well 10 to a final position where motor 16 is downstream of perforations 27 (
Fluids flowing through perforations 27 travel in a direction towards wellhead assembly 28, continue upwards past the motor towards packer, and go through a 180° tum into the open end of inverted shroud 42 towards intake 24. Gas keeps moving with well fluid F and pump 18 pressurizes and pumps the combined gas and liquid mixture to the surface as in a conventional method. If ESP 14 has to be pulled out for any reason, ESP 14 can be retrieved safely with production tubing 34.
Therefore, as disclosed herein, embodiments of the systems and methods of this disclosure will prevent the accumulation of gas at a bottom side of packer. The free gas is instead kept mixed with the liquid components of well fluid F, reducing the degradation of electrical and mechanical components in the region of packer, and increasing the reliability of ESP 14. Systems and methods of this disclosure can be utilized with currently available ESP components and can reduce the overall life cycle costs of the ESP and prevent deferred production costs.
The coupling method is repeated for the installation of a pump (e.g., a pump 310) and a discharge head 312. The production tubing (e.g., pipe element 314) is typically threaded into the discharge head and entire downhole assembly is lowered into the well in step-wise manner as additional production tubing is connected by field personnel on the rig floor. Once the entire downhole assembly reaches the desired setting depth, a packer assembly (e.g., a packer 316) is set to contact the inner walls of the casing (e.g., outer tubular member 322), thereby providing the required isolation in the well prior to commencing production.
The system (e.g., split flange system 400) in
The split flanges may be split into two pieces, three pieces, or any practical number of pieces. Hereafter the split flanges are termed shroud base flanges, (e.g., shroud base flanges 402)
The shroud base flanges are configured with a set of inner bolt holes (e.g., inner holes 404) on an inner bolt circle (e.g., inner bolt circle 405). The inner bolt holes are configured to connect the shroud base flanges to the intake-protector interface using fasteners (e.g., first set of fasteners 421).
Installation includes connecting the shroud base to the shroud base flanges. Fasteners disposed through the outer bolt holes couple the shroud base to the shroud base flanges. The shroud base flanges are also configured with a set of outer bolt holes (e.g., outer holes 406) on an outer bolt circle (e.g., outer bolt circle 407). The outer bolt holes are configured to connect the shroud base flanges to an inverted shroud base (e.g., a shroud base 444) using fasteners (e.g., a second set of fasteners 428) and a set of shroud base bolt holes (e.g., shroud base holes 403).
Installation of the inverted shroud may occur after the downhole gauge (e.g., sensor 426), motor (e.g., motor 416), and protector (e.g., protector 420) have been connected. Installation includes placing the intake 424 (e.g., intake 424) over the protector and bolting the shroud base flanges onto a top surface (e.g., intake base flange top surface 430) of the intake base flange via the inner bolt holes. Fasteners disposed through the inner bolt holes couple the shroud base flanges and the intake base to the top of the protector.
Installation includes connecting the inverted shroud to the shroud base, and/or the inverted shroud directly to the shroud base flanges. In accordance with one or more embodiments coupling techniques are disclosed including the use of fasteners, friction, hook and groove, and threads.
Fasteners with split flanges. An inverted shroud downhole end may have a set of bolt holes (e.g., shroud bolt holes). The shroud bolt holes may correspond to and cooperate with a set of bolt holes (e.g., the outer holes) on the shroud base flanges or the shroud bolt holes (e.g., shroud bolt holes) may correspond to and cooperate with a set of base shroud holes (e.g., base shroud holes). The inverted shroud may couple to the shroud base using a set of fasteners, the shroud bolt holes, and the base shroud holes. The inverted shroud may couple directly to the shroud base flanges using a set of fasteners, the shroud bolt holes on the inverted shroud downhole end, and the outer holes on the shroud base flanges.
Friction with split flanges. Friction elements or a single friction element disposed in the inverted shroud may couple the shroud to the shroud base and/or to the shroud base flanges. An inverted shroud downhole end may have an exterior profile with a friction element such as an o-ring (e.g., a friction element) and a friction element groove such as an o-ring groove (e.g., a groove). The groove is configured for the o-ring. The friction element may correspond to and cooperate with an interior profile with a friction element preparation on the shroud base. The inverted shroud may couple to the shroud base using the exterior profile, the friction element, the groove, the interior profile, and the friction element preparation. The friction element may correspond to and cooperate with an interior profile with a friction element preparation on the shroud base flanges. The inverted shroud may couple directly to the shroud base flanges using the exterior profile, the friction element, the groove, the interior profile, and the friction element preparation.
Hook and groove with split flanges. A J-hook disposed in the inverted shroud may couple the shroud to the shroud base and/or to the shroud base flanges. An inverted shroud downhole end may have an exterior profile with a J-hook element (e.g., a hook). The hook may correspond to and cooperate with an interior profile with a J-slot-and-groove, i.e., a slot element (e.g., a slot) on the shroud base. The inverted shroud may couple to the shroud base using the exterior profile, the J-hook element, the interior profile, and the slot element. The hook may correspond to and cooperate with an interior profile with a J-slot-and-groove, i.e., a slot element (e.g., a slot) on the shroud base flanges. The inverted shroud may couple directly to the shroud base flanges using the exterior profile, the J-hook element, the interior profile, and the slot element.
Threads with split flanges. A thread disposed in the inverted shroud may couple the shroud to the integrated flange. An inverted shroud downhole end may have an exterior profile with a first thread element such as a male thread (e.g., a pin). The pin may correspond to and cooperate with an interior profile comprising a second thread element such as a female thread (e.g., a box) on the shroud base. The inverted shroud may couple to the shroud base using the exterior profile, the first thread, the interior profile, and the second thread element. The pin may correspond to and cooperate with an interior profile comprising a second thread element such as a female thread (e.g., a box) on the shroud base flanges. The inverted shroud may couple to the shroud base flanges using the exterior profile, the first thread element, the interior profile, and the second thread element.
External connections mainly facilitate fastening of the inverted shroud to the ESP. Substantially most fluid will not go through non-gastight gaps. Substantially most of the fluid preferentially flows in an uphole direction and then makes a U-turn thereby flowing in a downhole direction into the intake.
The inverted shroud system may include sealing (e.g., seal 450) to prevent passage of liquids and/or gases across the inverted shroud components. For example, sealing may be provided in the shroud base flanges and intake connection area with minimal modification to the intake. This may be achieved by including a gasket (e.g., seal 450) between the shroud base flanges and top surface of the intake base, which can all be bolted down to the protector. This forms a shroud-flange seal between the inverted shroud and the intake. The shroud base flanges and the top surface of the intake base may comprise o-ring grooves (e.g., o-ring groove 451) configured for use with an O-ring to provide sealing.
Likewise, sealing may be provided between the shroud base and the top surface of the shroud base flanges. For example, a gasket (e.g., seal 450) may be placed between the shroud base and the shroud base flanges with the fasteners through the outer bolt holes coupling the gasket between the shroud base and the shroud base flanges. This forms a shroud base-top surface seal between the inverted shroud and the intake. In another embodiment, the shroud base flanges and/or shroud base connection profiles may include a groove (e.g., o-ring groove 451) configured for use with an O-ring (e.g., seal 450) to provide sealing.
The extended flange is configured with a set of inner bolt holes (e.g., inner holes 504) on an inner bolt circle (e.g., inner bolt circle 505). The inner bolt holes are configured to connect the intake to the protector forming the intake-protector interface using fasteners (e.g., first set of fasteners 521).
Installation includes connecting the shroud base to the extended flange. Fasteners disposed through the outer bolt holes couple the shroud base to the extended flange. The extended flange is also configured with a set of outer bolt holes (e.g., outer holes 506) on an outer bolt circle (e.g., outer bolt circle 507). The outer bolt holes are configured to connect the extended flange to an inverted shroud base (e.g., a shroud base 544) using fasteners (e.g., a second set of fasteners 528) and a set of shroud base bolt holes (e.g. a set of base bolt holes 503).
The fasteners disposed through the outer bolt holes may couple the shroud base to the extended flange. The base bolt holes may correspond to and cooperate with the outer bolt holes on the extended flange. The shroud base may couple to the extended flange using the second set of fasteners, the base bolt holes on the shroud base, and the outer holes on the extended flange.
Installation of the inverted shroud may occur after the downhole gauge (e.g., sensor 526), motor (e.g., motor 516), and protector (e.g., protector 520) have been connected. Installation includes placing the intake (e.g., intake 524) over the protector and bolting the extended flange onto the protector via the inner bolt holes. Fasteners disposed through the inner bolt holes couple the extended flange of the intake base to the top of the protector.
Installation includes connecting the inverted shroud to the shroud base, and/or the inverted shroud directly to the extended flange. In accordance with one or more embodiments coupling techniques are disclosed including the use of fasteners, friction, hook and groove, and threads.
Fasteners with extended flange. An inverted shroud downhole end may have a set of bolt holes (e.g., shroud bolt holes). The shroud bolt holes may correspond to and cooperate with a set of bolt holes (e.g., the outer holes) on the extended flange or the shroud bolt holes may correspond to and cooperate with a set of base shroud holes. The inverted shroud may couple to the shroud base using a set of fasteners, the shroud bolt holes, and the base shroud holes. The inverted shroud may couple directly to the extended flange using a set of fasteners, the shroud bolt holes on the inverted shroud downhole end, and the outer holes on the extended flange.
Friction with extended flange. Friction elements or a single friction element disposed in the inverted shroud may couple the shroud to the shroud base and/or to the extended flange. An inverted shroud downhole end may have an exterior profile with a friction element such as an o-ring (e.g., a friction element) and a friction element groove such as an o-ring groove (e.g., a groove). The groove is configured for the o-ring. The friction element may correspond to and cooperate with an interior profile with a friction element preparation on the shroud base. The inverted shroud may couple to the shroud base using the exterior profile, the friction element, the groove, the interior profile, and the friction element preparation. The friction element may correspond to and cooperate with an interior profile with a friction element preparation on the extended flange. The inverted shroud may couple directly to the extended flange using the exterior profile, the friction element, the groove, the interior profile, and the friction element preparation.
Hook and groove with extended flange. A J-hook disposed in the inverted shroud may couple the shroud to the shroud base and/or to the extended flange. An inverted shroud downhole end may have an exterior profile with a J-hook element (e.g., a hook). The hook may correspond to and cooperate with an interior profile with a J-slot-and-groove, i.e., a slot element (e.g., a slot) on the shroud base. The inverted shroud may couple to the shroud base using the exterior profile, the J-hook element, the interior profile, and the slot element. The hook may correspond to and cooperate with an interior profile with a J-slot-and-groove, i.e., a slot element (e.g., a slot) on the extended flange. The inverted shroud may couple directly to the extended flange using the exterior profile, the J-hook element, the interior profile, and the slot element.
Threads with extended flange. A thread disposed in the inverted shroud may couple the shroud to the integrated flange. An inverted shroud downhole end may have an exterior profile with a first thread element such as a male thread (e.g., a pin). The pin may correspond to and cooperate with an interior profile comprising a second thread element such as a female thread (e.g., a box) on the shroud base. The inverted shroud may couple to the shroud base using the exterior profile, the first thread, the interior profile, and the second thread element. The pin may correspond to and cooperate with an interior profile comprising a second thread element such as a female thread (e.g., a box) on the extended flange. The inverted shroud may couple to the extended flange using the exterior profile, the first thread element, the interior profile, and the second thread element.
The inverted shroud system may include sealing (e.g., seal 550) to prevent passage of liquids and/or gases across the inverted shroud components. Sealing may be provided between the shroud base and the top surface of the extended flange. For example, a gasket (e.g., seal 550) may be placed between the shroud base and the extended flange with the fasteners through the outer bolt holes coupling the gasket between the shroud base and the extended flange. This forms a shroud-extended flange seal between the inverted shroud and the intake. In another embodiment, the extended flange and/or shroud base connection profiles may include a groove (e.g., o-ring groove 551) configured for use with an O-ring (e.g. seal 550) to provide sealing.
The system (e.g., integrated flange system 600) in
The integrated shroud base 602 is configured with a set of inner bolt holes (e.g., inner holes 604) on an inner bolt circle (e.g., inner bolt circle 605). The inner bolt holes are configured to connect the intake to the protector forming the intake-protector interface using fasteners (e.g., first set of fasteners 621).
Installation of the integrated shroud may occur after the downhole gauge (e.g., sensor 626), motor (e.g., motor 616), and protector (e.g., protector 620) have been connected. Installation includes placing the intake (e.g., intake 624) over the protector and bolting the integrated flange onto the protector via the inner bolt holes. Fasteners disposed through the inner bolt holes couple the integrated flange of the intake base to the top of the protector.
Installation includes connecting the shroud to the integrated flange. In accordance with one or more embodiments coupling techniques are disclosed including the use of fasteners, friction, hook and groove, and threads.
Fasteners with integrated flange. Fasteners disposed through the outer bolt holes may couple the shroud to the integrated flange. An inverted shroud downhole end may have a first set of bolt holes (e.g., shroud bolt holes). The shroud bolt holes may correspond to and cooperate with a second set of bolt holes (e.g., a base shroud holes) on the integrated shroud base flange. The inverted shroud may couple to the integrated shroud base using a set of fasteners, the first set of bolt holes (shroud bolt holes) on the inverted shroud downhole end, and the second set of bolt holes (base shroud holes) on the integrated shroud base flange.
Friction with integrated flange. Friction elements or a single friction element disposed in the inverted shroud may couple the shroud to the integrated flange. An inverted shroud downhole end may have a friction element such as an o-ring (e.g., a friction element) and a friction element groove such as an o-ring groove (e.g., a groove). The groove is configured for use with the o-ring. The friction element may correspond to and cooperate with a friction element preparation on the integrated shroud base flange. The inverted shroud may couple to the integrated shroud base using the friction element, the groove, and the friction element preparation.
Hook and groove with integrated flange. A J-hook disposed in the inverted shroud may couple the shroud to the integrated flange. An inverted shroud downhole end may have an exterior profile with a J-hook element (e.g., a hook). The hook may correspond to and cooperate with an interior profile comprising a J-slot-and-groove, i.e., a slot element (e.g., a slot) on the integrated shroud base flange. The inverted shroud may couple to the integrated shroud base using the exterior profile, the J-hook element, the interior profile, and the slot element.
Threads with integrated flange. A thread disposed in the inverted shroud may couple the shroud to the integrated flange. An inverted shroud downhole end may have an exterior profile with a first thread element such as a male thread (e.g., a pin). The pin may correspond to and cooperate with an interior profile comprising a second thread element such as a female thread (e.g., a box) on the integrated shroud base flange. The inverted shroud may couple to the integrated shroud base using the exterior profile, the first thread, the interior profile, and the second thread element.
The inverted shroud system may include sealing (e.g., a seal 650) to prevent passage of liquids and/or gases across the components of the integrated flange to the shroud interface. Sealing may be provided between the shroud and the integrated base flange. For example, a gasket (e.g., the seal 650) may be placed between the shroud and the integrated flange with the fasteners through the outer bolt holes coupling the gasket between the shroud base and the integrated flange. This forms a shroud-integrated base seal between the inverted shroud and the intake. In another embodiment, the integrated flange and/or shroud base connection profiles may include a groove (e.g., o-ring groove 651) configured for use with an O-ring (e.g., the seal 650) to provide sealing.
A fastener access gap (e.g., a gap 652) is formed above the top surface of the intake base flange. The gap may be, for example, between the top surface of the intake base flange and a bottom surface of a downhole end of an intake body. A design parameter for the intake is that the gap is configured to allow bolts and/or studs (e.g., stud 654) to be disposed in the gap. A design parameter of the bolts and/or studs is that they are of sufficient length (e.g., customary length or longer than is customary) to couple the intake base flange to the protector top flange. Therefore, the gap is configured to provide access to the longer bolts to be used in the assembly.
With regards to the inverted shroud, it may be a challenge to handle a very long single length inverted cylinder during field installation. In accordance with one or more embodiments, the shroud length is divided into a set of housing sections. Each housing section may have a length of, for example, ten feet. The housing sections can be any length other than ten feet. Each housing section can be connected to an adjoining section to assemble the inverted shroud.
The system (e.g., friction module system 700) in
To assemble the friction modules, two adjoining friction modules, an upper friction module and a lower friction module, are stacked on top of one another during equipment installation at the wellsite. The upper friction module is coupled to the lower friction module using the o-ring and the friction o-ring contact surface thereby forming a friction module interface (e.g., friction module interface 753). The friction modules may be configured to couple to a shroud base (e.g., shroud base 744). For example, the module downhole end may couple to the shroud base at a shroud base friction end of the inverted shroud base.
A seal may be disposed between the friction module downhole end and shroud base friction end and/or the inverted shroud friction end to form a shroud module first seal between the friction module and the inverted shroud. A seal, in addition to the o-ring, may be disposed between the upper friction module downhole end and the lower friction module uphole end thereby forming a shroud module second seal. In this manner, the seals may form a seal between the inverted shroud and the intake.
Friction modules may be used together with other inverted shrouds. Coupling the inverted shroud to the ESP may include coupling a friction module downhole end 741 of a first friction module to a shroud friction element in an inverted shroud friction end. The first friction module may have the module friction element disposed in the first friction module downhole end. A second friction module (e.g., the upper friction module) may couple to the first friction module (e.g., the lower friction module). Coupling the inverted shroud to the ESP may include coupling a second friction module downhole end of the second friction module to a first friction element disposed in a first friction module uphole end. The second friction module may have the second friction element disposed in the second friction module downhole end.
The system (e.g., slot module system 800) in
To assemble the slot modules, two adjoining slot modules, an upper slot module and a lower slot module, are stacked on top of one another during equipment installation at the wellsite. The upper slot module is coupled to the lower slot module using the J-hook and the slot thereby forming a slot module interface (e.g., slot module interface 853). The coupling method includes engaging the J-hook of the upper slot module into the slot of the lower slot module. The method continues by rotating the upper slot module and/or the lower slot module relative to each other thereby engaging the upper module's J-hook with the lower module's slot.
The slot modules may be configured to couple to the shroud base (e.g., shroud base 844). The first hook element of the first slot module downhole end is coupled to a shroud slot element in a shroud base slot end. For example, the module downhole end may couple to the shroud base at a shroud base slot end of the inverted shroud base.
A seal may be disposed between the slot module downhole end (e.g., a hook end) and the shroud base slot end and/or the inverted shroud slot end to form a shroud module first seal between the slot module and the inverted shroud. A seal may be disposed between the upper slot module downhole end and the lower slot module uphole end thereby forming a shroud module second seal. In this manner the seals may form a seal between the inverted shroud and the intake.
Slot modules may be used together with other inverted shrouds. Coupling the inverted shroud to the ESP may include coupling the slot module downhole end 841 of a first slot module to a shroud slot element in an inverted shroud slot end. The first slot module may have the module slot element disposed in the first slot module downhole end. A second slot module (e.g., the upper slot module) may couple to the first slot module (e.g., the lower slot module). Coupling the inverted shroud to the ESP may include coupling a second slot module downhole end of the second slot module to a first slot element disposed in a first slot module uphole end. The second slot module may have the second slot element disposed in the second slot module downhole end.
Note that the contact forces are such that they can hold the sections together during assembly and, in use, and can also be easily disassembled. In accordance with one or more embodiments, the well fluid preferentially flows on the outside of the inverted shroud to the top, makes a U-turn and flows down towards the intake.
The system (e.g., threaded module system 900) in
The threaded connections between adjoining threaded modules may follow customary oilfield practice for production tubing and/or casing connections. For example, a first thread module of a pair of adjoining threaded modules may have an external thread (e.g., pin 901) and a second thread module of the pair may have an internal thread (e.g., box 903). Both threaded modules can be threaded together on the rig floor using torquing tongs during assembly of the ESP. The threaded module may be bolted to or could thread directly onto the extended flange and/or the integrated flange. The threaded module may thread to the split flanges using specialized manufacturing of the split flanges such as the manufacturing technique used for manufacturing casing slips used in casing hangers and tubing slips used in tubing hangers.
To assemble the threaded modules, two adjoining threaded modules, an upper threaded module and a lower threaded module, are stacked on top of one another during equipment installation at the wellsite. The upper threaded module is coupled to the lower threaded module. The upper threaded module is coupled to the lower threaded module using the external threads and the internal threads respectively, thereby forming the threaded module interface 953. The threaded module may be configured to couple to a shroud base (e.g., shroud base 944). For example, the module downhole end may couple to the shroud base at a shroud base threaded end of the inverted shroud base.
Threaded modules may be used together with other inverted shrouds. Coupling the inverted shroud to the ESP may include coupling the threaded module downhole end 941 of a first threaded module to a shroud threaded element in an inverted shroud threaded end. The first threaded module may have the module threaded element disposed in the first threaded module downhole end. A second threaded module (e.g., the upper threaded module) may couple to the first threaded module (e.g., the lower threaded module). Coupling the inverted shroud to the ESP may include coupling a second threaded module downhole end of the second threaded module to a first threaded element disposed in a first threaded module uphole end. The second threaded module may have the second threaded element disposed in the second threaded module downhole end.
The pin 901 and the box 903 may not have compatible threads and therefore a combination coupling may be used to form the threaded module interface 953. For example, a combination coupling may be used to adapt a pin thread of a first thread form to a box thread of a second thread form. Likewise for differing sizes of threads, an adapter such as the reducer coupling may be used. In each case, the threaded module interface may include a threaded seal.
The threaded module downhole end 941 and the threaded module uphole end 943 may each have a pin thread. In that case, a coupling may be used. In like manner, the threaded module downhole end 941 and the threaded module uphole end 943 may each have a box thread. In that case a nipple may be used to form the threaded module interface.
Upon assembly the threaded connection formed by sealing threads provides sealing at the threaded module interface. The threaded modules may be configured for use with one or more of a gasket such as a gasket disposed at the threaded module downhole end and/or at the threaded module uphole end. The gasket may seal at the threaded module interface. The threaded modules may be configured with one or more gaskets in addition to sealing threads.
In each of the above embodiments, the installation method may include an alternating installation sequence wherein as each ESP component is installed, an inverted shroud housing section is installed before progressing to installing the next ESP component. The method is reversed during retrieval of the inverted shroud.
The embodiments disclosed within do not limit in any way the scope of this invention. It is possible that different combinations of the components, systems, and method highlighted in this disclosure can be implemented. For example, the system may include a combination of the shroud base flanges, extended intake base flange, and integrated shroud-intake base with any of the modular housing assembly methods, friction modules, slot modules, and/or threaded modules.
The shroud base flanges, the extended base flange, and/or the integrated base flange may be made with an incline instead of with the horizontal arrangement shown. The inclined feature may ensure no fluid dead zones (fluid in a stagnant condition) exist just below the intake assembly.
Standard centralizers may be used between the outer diameter of the inverted shroud and the internal diameter of the casing. The centralizers ensure the inverted shroud does not contact an internal diameter of the casing during installation downhole. Furthermore, use of centralizers may avoid erosion issues. The use of centralizers promotes concentricity of the ESP, shroud, and casing ID. Centralizers may ensure approximately equal radial clearances between the casing and the inverted shroud. Approximately equal radial clearances may promote a near-concentric flow area and fluid velocity during operation. Non-concentric radial clearances may increase fluid flow velocity. The high velocity from the non-concentric radial clearances may create erosion issues. In this manner the centralizers may avoid the erosion. Centralizers may be used between the outer diameter of the ESP assembly components and the internal diameter of the shroud. The centralizers may provide the benefits described previously.
Power Cable/Motor Lead Extension (MLE) attachments may be used. The cable supplying power to the motor needs to go past the inverted shroud assembly to the motor further downhole. This cable needs to be held in place to ensure a sturdy assembly. Cable bands are typically used in ESP installations to attach cables to production tubing and/or the ESP assembly. For the inverted shroud application, if the cable is to go along the outer diameter of the shroud, a cable band may be used. Alternatively, a cable clamp may be used. To reduce the size of the cable clamp due to additional diameter from the cable thickness, a cable groove and/or cable slot may be machined on the outer diameter of the inverted shroud so the cable may be recessed within the cable groove and/or cable slot.
If the power cable is to go through the internal section of the inverted shroud, then the cable can be affixed to the production tubing and the ESP assembly components using the standard cable bands. However, a through-access is incorporated at one or more of the lower housing section of the inverted shroud, the shroud base, or the shroud base flanges. Design parameters for the preferred option is based on space availability, which can be ascertained during the engineering design for the specific field application.
Turning to
In Block 1110, an electrical submersible pump assembly (ESP) with a pump, an intake, shroud base flanges, a protector, and a motor is provided.
In Block 1120, fluid communication is provided between a production tubing and the ESP. The production tubing delivers well fluid containing both gases and liquids from the ESP into a wellhead assembly through an inner bore of the production tubing.
At step 1130, a packer is located downstream of the ESP and circumscribes the production tubing.
At step 1140, shroud base flanges are coupled to a top surface of an intake base flange. The intake base flange is on an intake downhole end of the intake. The shroud base flanges are coupled using a first set of fasteners, a set of inner bolt holes disposed on the shroud base flanges, and a set of protector top bolt holes disposed on a protector top surface of a protector top flange of the protector.
At step 1150, a closed end of an inverted shroud is located between the intake and the protector. The inverted shroud has a shroud base disposed on the closed end. The inverted shroud has an opposite open end that is open toward the packer assembly.
At step 1160, the inverted shroud is coupled to the shroud base flanges using a second set of fasteners, a set of outer bolt holes disposed on the shroud base flanges, and a set of shroud base bolt holes disposed on the shroud base. The packer assembly is located uphole of the opposite open end at a distance causing a mixing of a gas pocket with the well fluids to form a combined gas and liquid mixture, and directing the combined gas and liquid mixture in a direction toward the intake.
Although only a few example embodiments have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from this invention. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures. It is the express intention of the applicant not to invoke 35 U.S.C. § 112(f) for any limitations of any of the claims herein, except for those in which the claim expressly uses the words ‘means for’ together with an associated function.
