Hanger and penetrator for through tubing ESP deployment with a vertical production tree

A hanger assembly for use in a vertical production tree that includes an annular piping spool member having a side opening, and a hanger having an outer surface profiled to selectively land in the piping spool member and a side opening registered with the side opening of the piping spool member. The hanger assembly also includes a vertical penetrator having an end selectively connected to a submersible device and an opposing end inserted into the hanger, and that is in communication with the side openings.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present technology relates to oil and gas production. In particular, the present technology relates to the deployment of electric submersible pumps in vertical production trees.

2. Description of the Related Art

Production trees are typically used during the production of oil and gas on both surface and subsea wells. Production trees principally isolate, direct, and control the flow of oil, gas, and other fluids out of a well, and generally include valves that control such flow. In addition, production trees can be used to perform other functions, such as injecting chemicals into a well, relieving pressure from a well, and monitoring conditions within the well. Typically, production trees are classified as either horizontal or vertical production trees. Horizontal production trees are those where the oil and gas is brought to the wellhead, and then diverted horizontally through the master valves, swab valve, and other components. Vertical production trees are those where the production path, including components of the tree such as the master valves and swab valve, are stacked vertically above the wellhead.

In many wells, the pressure within the well is sufficient that producing oil and gas from the well requires only the installation of a production tree, and the opening of valves on the tree to allow the oil and gas to flow out of the well. In some instances, however, the pressure in the well is not sufficient to produce the oil and gas at acceptable rates. In such circumstances, it can be necessary to add an artificial lift mechanism, such as an electric submersible pump (ESP), to help lift the oil and gas from the well. Furthermore, in some circumstances, a well that initially has sufficient pressure to produce without artificial lift may experience a decrease in well pressure, thereby arriving at a point where artificial lift is required.

SUMMARY OF THE INVENTION

One embodiment of the present technology provides a hanger assembly for use in a vertical production tree. The hanger assembly includes an annular piping spool member having a side opening, and a hanger having an outer surface profiled to selectively land in the piping spool member and a side opening registered with the side opening of the piping spool member. The hanger assembly also includes a vertical penetrator having an end selectively connectable to a submersible device and an opposing end inserted into the hanger, and that is in communication with the side openings. The hanger assembly can also include a submersible device attached to and suspended from the hanger, the submersible device electrically connected to surface equipment through the side openings of the hanger and the piping spool member.

In addition, the piping spool member can have a shoulder and can be located in the vertical production tree below the master production valve of the vertical production tree, and the hanger can have a lip arranged to contact the shoulder of the piping spool member to limit downward movement of the hanger relative to the piping spool member.

The piping spool member can have a pin and the hanger can have a slot, the pin and the slot positioned so that the slot must accept the pin for the hanger to be fully seated against the piping spool member with the lip of the hanger contacting the shoulder of the piping spool member, and so that when the pin and slot are aligned, the opening on the side of the hanger is aligned with the side opening of the piping spool member. In addition, the hanger assembly can include a plug for insertion into the side opening of the piping spool member to seal the opening during makeup and breakdown of the assembly.

In some embodiments, the piping spool member can have multiple fluid bypass ports, the aggregate cross-sections of which are large enough to limit fluid velocity below a predetermined velocity. In addition, the hanger can include a latching shape at an upper end configured for releasable attachment to a running tool. The vertical penetrator of the hanger assembly can also contain cables for connection to a submersible device, wherein the inside of the vertical penetrator and the opening in the hanger and the piping spool member are isolated from pressure in a well bore.

Another embodiment of the present technology provides a vertical production tree, which includes a piping spool, and a hanger assembly positioned in the piping spool. The hanger assembly includes a piping spool member having shoulder, a side opening, and a fluid bypass port, the piping spool member attached to the tubing bonnet, and a hanger adapted for insertion in the piping spool member, and having a lip arranged to contact the shoulder of the piping spool member to limit downward movement of the hanger relative to the piping spool member, the hanger having a vertical penetrator that is open to a side of the hanger and that can be accessed via the side opening of the piping spool member. The hanger assembly also has a submersible device attached to and suspended from the hanger, the submersible device electrically connected to surface equipment through the hanger and the side opening of the piping spool member. The inner diameter of the piping spool member is large enough to allow passage of the submersible device.

As claimed herein below, the fluid bypass port of the piping spool member is separate from the side opening, so that an operator can control the submersible device by communicating with the submersible device and providing power through the side opening while oil and gas is simultaneously being produced through the fluid bypass port. In addition, the hanger assembly can further include a plug for insertion into the side opening of the piping spool member to seal the opening during insertion and removal of the hanger assembly. The hanger can also include a latching shape at an upper end configured for releasable attachment to a running tool.

Yet another embodiment of the present technology provides a method of through tubing ESP deployment on a vertical production tree attached to the opening of a well. The method includes the steps of attaching a piping spool with a shoulder and a fluid bypass port to a wellhead tubing hanger below the master valve of a vertical production tree so that an opening on the sidewall of the piping spool aligns with an opening in a sidewall of the wellhead tubing hanger, and sealing the opening in the wellhead tubing hanger with a plug. The method also includes deploying an electric submersible pump (ESP) through the piping spool and wellhead tubing hanger, and down the wellbore to a predetermined location in the production tubing, the ESP suspended by a cable, and attaching a cable hanger having a circumferential lip and a side port to the cable. In addition, the method includes running the cable hanger into the piping spool and setting the cable hanger so that the circumferential lip contacts the shoulder of the piping spool and the side port of the cable hanger is aligned with the openings of the piping spool and the wellhead tubing hanger, and removing the plug from the opening in the wellhead tubing hanger and electrically communicating with the ESP through the openings in the wellhead tubing hanger and piping spool, and the side port of the cable hanger.

In some embodiments, the method can further include one or more of the steps of installing a lubricator and blow-out preventer (BOP) above the lower master valve before the step of deploying the ESP, installing the ESP in the lubricator, opening the BOP and lubricator, and pressurizing the ESP to the well pressure before deploying the ESP into the well. Further steps can also include closing the BOP on the cable attached to the ESP before the ESP reaches its setting depth, bleeding the pressure from the lubricator, and removing the lubricator, thereby exposing the cable prior to the step of attaching the cable hanger to the cable.

Some embodiments of the method can also include reinstalling the lubricator after attaching the cable hanger to the cable, opening the BOP to release the cable, thereby allowing the ESP to travel further down the well, attaching a running tool to the cable hanger and using the running tool to run the cable hanger into position relative to the piping spool, closing the lower master valve, and removing the BOP and lubricator prior to the step of removing the plug from the opening in the wellhead tubing hanger.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

The foregoing aspects, features, and advantages of the present technology will be further appreciated when considered with reference to the following description of preferred embodiments and accompanying drawings, wherein like reference numerals represent like elements. In describing the preferred embodiments of the technology illustrated in the appended drawings, specific terminology will be used for the sake of clarity. However, the embodiments are not intended to be limited to the specific terms used, and it is to be understood that each specific term includes equivalents that operate in a similar manner to accomplish a similar purpose.

FIG. 1is a side partial cross-sectional view of a vertical production tree10according to an embodiment of the present technology. The vertical production tree10includes a lower master valve12which is positioned above a tubing bonnet14. The tubing bonnet14is attached to a hanger assembly16, the structure of which is shown in greater detail inFIG. 2, and which is capable of allowing passage of an electric submersible pump (ESP)17or other device in to the well without removal of the vertical production tree10. Although one embodiment of the technology can be used to aid in insertion of an ESP into a well, it is to be understood that other tools and devices can be introduced to the well through the technology herein described. Examples of other such tools and devices include heater cables for gas well deliquidification, alternative types of artificial lift systems, such as progressive cavity pumps, and systems for monitoring well parameters, such as temperature, pressure, and corrosion. For ease of discussion, an ESP is discussed hereinbelow in describing the technology, but the invention is not limited to use with an ESP.

Below the hanger assembly16are additional components that are part of the vertical production tree10, such as, for example, a tubing spool18, a casing spool20, and a casing heel22. Various control valves24are positioned on the vertical production tree10to regulate the flow of liquids into and out of the tree as required by production operations. A swab valve25on an upper end of the vertical production tree10provides selective access to its main bore. The vertical production tree10sits at the top of a well26, and encloses production tubing28that extends into the well26and provides a conduit for oil and gas to exit the well26through the vertical production tree10.

Referring toFIG. 2, there is shown an enlarged cross-sectional view of the hanger assembly16according to the present technology. The hanger assembly16has an annular piping spool30with a piping spool shoulder32and a piping spool opening34. Piping spool shoulder32is defined where an inner diameter DPLof spool30reduces to form a ledge. Piping spool opening34projects radially through a side wall of the piping spool30above the piping spool shoulder32. The upper end36of the piping spool30is adapted to attach to the tubing bonnet14such as, for example, using bolts38or other fasteners (as shown inFIG. 1).

An annular fluid bypass port member40is adapted for positioning coaxially within a main bore41in the piping spool30. The outer diameter of the fluid bypass port member40is slightly smaller than the inner diameter DPLof the piping spool30above the piping spool shoulder32, so that when the fluid bypass port member40is positioned within the piping spool30, a bottom end41of the fluid bypass port member40rests against and is supported by the piping spool shoulder32. Thus, downward movement of the fluid bypass port member40relative to the piping spool30is restricted by the piping spool shoulder32. The fluid bypass port member40can also include recesses42circumscribing its outer surface for receiving seals43. The seals43can be elastomeric, and seal the interface between the piping spool30and the fluid bypass port member40. The inner diameter of the fluid bypass port member40is large enough to allow the passage of the ESP17. Furthermore, the fluid bypass port member40further includes a fluid bypass port member shoulder44on the inner surface thereof. In some embodiments, the piping spool30and fluid bypass port member40can be one integral piece.

The fluid bypass port member40includes at least one production port45, shown formed axially through fluid bypass port member40and offset from Axis Axof main bore41, which provides a path for oil, gas, and other fluids to pass from below the hanger assembly16to above the hanger assembly16. In alternate embodiments, there can be multiple production ports. The cross-sectional area of the production port45, or the aggregate cross-sectional area of the multiple production ports, as the case may be, is large enough to keep the flow velocity of the fluids through the ports below a threshold specified by industrial standards.

FIG. 2also shows a cable hanger46that is adapted for insertion in the fluid bypass port member40. The cable hanger46has an outer diameter that transitions inward to define a downward facing cable hanger lip48, shown landed on the upward facing fluid bypass port member shoulder44. The interaction between the fluid bypass port member shoulder44and the lip48of the cable hanger46supports cable hanger46in the vertical production tree10, and limits its downward movement relative to the fluid bypass port member40. In some embodiments, the cable hanger46can have recesses50circumscribing its outer surface for accepting seals52. The seals52can be elastomeric, and can seal the interface between the inner surface of the fluid bypass port member40and the outer surface of the cable hanger46.

The cable hanger46ofFIG. 2also includes a latch53at an upper end thereof that is shaped to releasably connect with a running tool (not shown). During makeup of the hanger assembly16, and in particular insertion of the cable hanger46into the fluid bypass port member40, the running tool can be attached to the latch53to direct the movement of the cable hanger46into the assembly16. When the cable hanger46is landed, the running tool can then release the latch53and be removed. In addition, the cable hanger46also includes a vertical penetrator54that extends axially into the cable hanger46from the bottom56thereof, and that houses cables58. The vertical penetrator54can be separate from the from the cable hanger46, and can be machined or molded to prevent the ingress of production fluids. In addition, the vertical penetrator54can be held in place relative to the cable hanger46by a should or thread (not shown). In addition, the cable58can be attached to the vertical penetrator54by any appropriate means, such as, for example, with a slip and nut connector similar to a coiled tubing connector, or by cable heading if braided cable is used. The cable58extends downhole through a cable connector60to the ESP17to provide power, controls, etc. to the ESP17or other device.

The piping spool30, fluid bypass port member40, and cable hanger46have side openings62A,621B, and62C respectively. Openings62A,62B, and62C are shown registered with one another and extending radially outward from axis Ax. These side openings62A,62B,62C provide access from outside the piping spool30to a cable connection64at the top of the cables58within the vertical penetrator54. The cable connection64can be, for example, a 3-phase AC power supply. When the openings62A,62B, and62C are properly aligned, cables66can be passed through the openings62A,62B, and62C and connected to the cable connection64. Through the cables58,66, the ESP17can be electrically connected to equipment outside the vertical production tree10. This electrical connection can provide power to the ESP17, as well as other data, such as control data, etc. The openings62A,62B, and62C are separated from the flow area67so that the cable connection64can be accessed and the ESP17can be controlled while oil and gas is being simultaneously produced through production port(s)45.

To ensure that the opening62A of the cable hanger46aligns with the openings62B,62C of the fluid bypass port member40and piping spool30upon insertion of the cable hanger46, self-orienting mechanisms are provided in the assembly16. For example, in the embodiment shown inFIG. 2, a self-orienting pin68can be included in the inner sidewall of the fluid bypass port member40, and can protrude inwardly from the inner surface of the fluid bypass port member40. In addition, a self-orienting pin receiving slot70can be cut in a portion of the outer surface of the cable hanger46. The self-orienting pin68and the self-orienting pin receiving slot70are arranged so that when aligned, the opening62A of the cable hanger46aligns with the openings of62B,62C of the fluid bypass port member40and the piping spool30respectively. When the cable hanger46is inserted into the fluid bypass port member40, unless the self-orienting pin68and the self-orienting pin receiving slot70are aligned, the cable hanger46cannot fully insert into the fluid bypass port member40. Instead, the bottom of the cable hanger46will contact self-orienting pin68rather than the self-orienting pin68being inserted into self-orienting pin receiving slot70. Thus, when the cable hanger46is fully seated, an operator will know that the openings62A,62B,62C are aligned.

The hanger assembly16shown inFIG. 2and described herein above is effective to allow insertion of the ESP17through the fluid bypass port member40, and subsequent control of the ESP17by cable through openings62A,62B,62C in the side of the of components of the hanger assembly16. In addition, the assembly still allows production of oil and gas through the vertical production tree because the fluids can pass the hanger assembly16via the production port(s)45in the fluid bypass port member40. Insertion of the ESP17and makeup of the hanger assembly16is described in detail below.

Installation of the piping spool30and fluid bypass port member40can be accomplished while the well is dead. Initially, the well is killed, and all components from the lower master valve12upward are removed from the production tree10(shown inFIG. 1). Next, the piping spool30and fluid bypass port member40, which can be preassembled together, are attached to the wellhead tubing spool18using, for example, fasteners72(shown inFIG. 1), which may be bolts. The openings62A,62B, and62C are closed with a plug74or cap that can be inserted into the opening62C in the piping spool30. The plug74can be held in place by any appropriate means. For example, the plug74may have external threads76that correspond to internal threads78in opening62C. The purpose of the plug74can be to cover and electrically protect the cable connection64. After the piping spool30and fluid bypass port member40are attached to the wellhead tubing spool18, the lower master valve12and other wellhead components are reinstalled on top of the piping spool30. As shown inFIG. 1, tubing bonnet14can be positioned between the lower master valve12and the hanger assembly16. The piping spool30can be attached to the tubing bonnet14, lower master valve12, or other components by any appropriate means, such as, for example, with fasteners38.

With the piping spool30and fluid bypass port member40thus attached to the vertical production tree10, the ESP17can be lowered into and set in the well26while the well is live. To accomplish this, a pressure containing lubricator79and a blowout preventer (BOP)81are installed above the lower master valve12. The cable58is attached to the ESP17at a top end and the ESP17is inserted into the lubricator by passing through a stuffing box83through pressure containing seals at the top of the lubricator. At this point, the BOP is opened, and the lubricator and ESP17are pressurized up to the well pressure.

Once it has been pressurized, the ESP17is deployed downwardly through the vertical production tree10, including through the piping spool30and fluid bypass port member40, to a predetermined location in the well. As the ESP17is lowered, the cable58is fed into the well so that the lower end of the cable58remains attached to the ESP17and the upper end remains above the BOP and outside of the well. Just before the ESP17reaches its intended setting depth, the BOP is closed on the cable58to hold the cable58and the ESP17in place and to contain the well pressure. Then the lubricator pressure is bled off, and the lubricator is removed, thereby exposing the top of the cable58.

With the lubricator removed, the cable hanger46is attached to the top of the cable58, with the cable58extending into the vertical penetrator54as shown inFIG. 2. The cable hanger46is then attached, via the latch53, to a running tool to complete installation of the cable hanger46and the ESP17. The lubricator is reinstalled, the BOP is reopened, and the running tool pushes the cable hanger46downward until it is seated on the fluid bypass port member40as described above. The self-orienting pin68and self-orienting pin receiving slot70, of the fluid bypass port member40and the cable hanger46respectively, align to ensure that when the cable hanger46is fully seated the opening62A aligns with openings62B,62C of the fluid bypass port member40and the piping spool30. Once the cable hanger46is set, the running tool is released from the latch53and retrieved into the lubricator. The lower master valve12is then closed and the lubricator and BOP are removed. On the piping spool30, the previously installed plug74can be removed from the opening62C, and cable66can be connected to cable connection64to establish electrical communication between the ESP17and surface equipment outside the vertical production tree10. To withdraw the ESP17from the well, the above described process is reversed.

One advantage to the technology described herein is that is reduces the need to replace vertical wellheads with horizontal wellheads in order to introduce an ESP or other device into a well through the wellhead. Instead, the technology of the present application allows for retrofitting existing vertical wellheads. This can be beneficial particularly in established oil fields, where vertical wellheads may already be in use, and replacement with horizontal wellheads would be costly and inefficient.

Although the technology herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present technology. It is therefore to be understood that numerous modifications can be made to the illustrative embodiments and that other arrangements can be devised without departing from the spirit and scope of the present technology as defined by the appended claims.