Patent ID: 12234700

DETAILED DESCRIPTION

It is to be understood that the following disclosure provides many different embodiments, or examples, for implementing different features of various embodiments. Specific examples of components and arrangements are described below to simplify the disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. Moreover, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact and may also include embodiments in which additional features may be formed interposing the first and second features, such that the first and second features may not be in direct contact.

Aspects of the invention relate to systems and methods for simultaneous milling and debris collection which may be utilized for example in various types of field tools and the like. For purposes of clarity and brevity, aspects of the invention are described generally with reference to well-based operations. How to utilize aspects of the invention in devices (e.g., intakes, pumps, motors, etc.) other than those exact devices will be understood by those skilled in the art in view of this disclosure.

As used herein, the terms “up” and “down”; “upper” and “lower”; “top” and “bottom”; and other like terms indicating relative positions to a given point or element are utilized to more clearly describe some elements. Commonly, these terms relate to a reference point as the surface from which drilling operations are initiated as being the top point and the total depth of the well being the lowest point, wherein the well (e.g., wellbore, borehole) is vertical, horizontal or slanted relative to the surface.

In various aspects, the disclosed systems can include a device that can perform mechanical operations for simultaneously milling and debris removal on a wireline. The device can include a motor and can, in some aspects, advantageously be configured to operate with a single motor, which can be electric, fuel-based, or hybrid. The device can further include a gear train coupled to the motor and configured to operate based on the operation of the motor. In particular, the gear train can include at least two rotational outputs having different rotational speeds relative to each other. Moreover, the device can include a fluid pump connected to the rotational outputs of the gear train, the fluid pump serving to aid in the flow of fluids (e.g., water, gas, oil, etc.) to aid in the drilling and debris removal process of the wireline device. The fluid pump can feature a pump housing and a pump input. Further, the pump housing can be coupled to one of the rotational outputs of the gear train and the pump input can be coupled to another rotational output of the gear train.

Additionally, the device can include a milling bailer that can serve to remove fluids during the operation of the device while performing a milling operation. The milling bailer can be coupled to the housing of the fluid pump and can be configured to rotate with the fluid pump housing. The milling bailer can further include a bailer portion shaped to intake fluid proximate a distal end of the bailer portion and allow the fluid to flow through a filter and through the fluid pump. Moreover, the milling bailer can include a milling face proximate the distal end of the bailer portion. This milling face can include at least one bit for milling for performing a milling operation while fluid is flowing through the bailer portion.

In some embodiments, a device that performs both milling and debris collection at the same time as described herein has several advantages as it improves the milling process by adding forced circulation and efficient debris removal. Further, debris collection may also be more effective as the debris may be continuously stirred and reduced in size by the device's milling bit.

FIG.1shows a legend for the symbols used in various diagrams of the remaining figures, in accordance with embodiments of the disclosure. In particular, diagram101shows a schematic symbol for a stationary body indicator102, a rotary seal indicator104, a rotary bearing indicator106, a fixed joint indicator108, a gear mesh indicator110, a fluid flow direction indicator112, a bit face indicator114, and a direction of rotation indicator116. In some aspects, the stationary body indicator102can indicate any object or surface that has a fixed position and does not move relative to the tool. For example, the stationary body indicator102can be used to indicate a connection between a wireline and an anchor. In that example, the anchor can be any object holding the wireline above the wellbore surface, such as a winch. In another aspect, the rotary seal indicator104can indicate a seal for a rotating body, such as a shaft. The rotary seal can provide sealing and wiping functionality, such that fluid on one side of the seal is not allowed to travel to the opposing side of the seal. In some aspects, the rotary bearing indicator106can indicate can be used to indicate a rotary bearing, which carries a load by placing rolling elements between two bearing rings. The relative motion of the two bearing rings can enable the rolling elements to roll with little rolling resistance and with little sliding.

The fixed joint indicator108can indicate a fixed connection point between two objects, such as by welding, fastening, or any other technique for coupling. The gear mesh indicator110can indicate a connection point between two gears where the gears mesh such that the gears can transmit power to one another. For example, the gears can have individual teeth that engage a pair of teeth from another gear. The gear teeth can be straight teeth as in spur gears, or can be helical, double helical, bevel, worm, or hypoid in nature. In addition, the gears can be formed conventionally with teeth on the other edges of the gear, or they can take the form of a gear ring with teeth along the inside surface, such as a planetary ring gear.

The fluid flow indicator112can indicate a direction of fluid flow relative to a tool or part of a tool. The bit face indicator114can indicate the presence of one or more milling bits used by a tool to perform a milling operation. The direction of rotation indicator116can indicate a direction of rotation of a tool or a portion of a tool, typically with respect to a central axis.

Further, diagram103shows an example schematic cross-sectional diagram of a planetary gear train having one input and one output, provided to illustrate an example using the schematics from diagram101. The input of this example gear train can be a shaft coupled to a sun gear120. The sun gear120can be central gear that is fixed to the input shaft such that it rotates at the same speed as the shaft. The sun gear120, in turn, is coupled to at least two planet gears122(also referred to as “planetary gears”) on opposing sides of the sun gear. Although only two planet gears122are shown, the assembly can include more than two planet gears122. As shown in the diagram103, each of the planet gears112meshes with the sun gear120at an interior mesh point118and meshes with a ring gear130at an exterior mesh point118. The housing can be a planetary ring gear130that is mounted to a housing124, as shown.

As stated previously, the symbols described above are used across various diagrams in the Figures to represent corresponding components. For example, elements231,241, and251ofFIG.2are mesh points illustrated using the gear mesh indicator110. Similarly, elements359ofFIG.3are rotary bearings illustrated using the rotary bearing indicator106.

The diagram103also includes a planetary carrier126upon which the planet gears122are mounted. In this example, the planet gears122are mounted using a rotary bearing128that allows the planet gears122to rotate freely with respect to the planetary carrier126. The movement of the planet gears122about the sun gear120thereby causes the planetary carrier126to rotate. As shown in the diagram103, the planetary carrier126includes an output, such as a shaft mounted to the planetary carrier126. The rotational movement of the planetary carrier is thereby converted to rotation of the output shaft.

FIG.2shows an example schematic of a stand-alone milling device, in accordance with embodiments of the disclosure. Such a device can be described by the schematic shown in cross-sectional diagram200and can mill metal or scale via a mechanical operation that can be run on wireline in order to remove an obstruction, remove scale from the borehole wall, enlarge the borehole, mill through valves and plugs, combinations thereof, and/or the like. In some aspects, the device can include a motor that drives the milling bit through a multi-stage gear train. The gear train can serve to convert high revolution per minute (RPM), low-torque motor output to a low-RPM, high-torque output at the bit, which can be used for milling.

In more detail, diagram200includes a schematic of an embodiment of a device that can be configured to perform milling operations and in which a motor204(e.g., an electric motor that is powered via an electrical connection202) can drive a milling bit212through a gear train207(e.g., a three-stage planetary gear train, to be described below).

In some respects, the gear train207can include a first stage206, a second stage208, and a third stage210. The gear train207can include a first rotational input203at the first stage206. The remaining stages of the gear train207(e.g., the second stage208and the third stage210) can be coupled to the first stage206and can be configured to modify the torque and/or power of the first stage206accordingly, and thereby transmit a predetermined amount of power to the milling bit212that performs a milling operation, as further described below.

In more detail, the first rotational input203at the first stage206can include a shaft217from motor204that can be coupled to a sun gear219. The sun gear219can include a central gear that is fixed to the input shaft217such that it rotates at the same speed as the shaft217. The sun gear219, in turn, is coupled to at least two planet gears234on opposing sides of the sun gear219. Although only two planet gears234are shown, the assembly can include more than two planet gears234. Further, only one of the pair of planetary gears are labeled in the diagram200to reduce clutter in the diagram. As shown in the diagram200, each of the planet gears234meshes with the sun gear219at an interior mesh point of the mesh points231and meshes with a ring gear235at an exterior mesh point of the mesh points231. In this example the ring gear235is fixed relative to the milling tool. For example, the ring gear235can be mounted to a housing236of the milling tool, as shown.

The diagram200also includes a planetary carrier227spanning the first stage206and second stage208upon which the planet gears234are mounted. In this example, the planet gears234are mounted using a rotary bearing233that allows the planet gears234to rotate freely with respect to the planetary carrier227. The movement of the planet gears234about the sun gear219thereby causes the planetary carrier227to rotate. The rotational movement of the planetary carrier227is thereby converted to second rotational input to the second stage208.

In more detail, the second rotational input at the second stage208can be coupled to a sun gear229of the second stage208. For example, rather than being coupled to a shaft217as explained with the sun gear219of the first stage206, the sun gear229of the second stage208can be coupled to the planetary carrier227of the first stage206. The sun gear229of the second stage208, in turn, can mesh with at least two planet gears244on opposing sides of the second rotational input. Although only two planet gears are shown, the assembly can include more than two planet gears. As shown in the diagram200, each of the planet gears244meshes with the sun gear229of the second stage208at an interior mesh point of the mesh points241and meshes with a ring gear246at an exterior mesh point of the mesh points241. Again, the housing of the second stage208can be a planetary ring gear that is mounted to a housing236, as shown, containing the planet gears244and providing an exterior mesh point241for the planet gears244. The planet gears244can be mounted to a second planetary carrier247using rotary bearings243, such that the planet gears244can rotate within the rotary bearings243, but rotational movement of the center of the planet gears244around the sun gear229causes the second planetary carrier247to rotate.

The rotational movement of the second planetary carrier247provides a third rotational input to the third stage210. The second planetary carrier247can span the second stage208and third stage210, at which point the second planetary carrier247can be coupled to a sun gear249of the third stage210such that the rotational velocity of the second planetary carrier247matches that of the sun gear249. The sun gear249, in turn, can mesh with two or more planet gears254. In this example, again, the planet gears254are mounted to a third planetary carrier257using a rotary bearing253that allows the planet gears to rotate freely with respect to the third planetary carrier257. The movement of the planet gears254thereby causes the third planetary carrier257to rotate.

Although only two planet gears are shown, the assembly can include more than two planet gears. As shown in the diagram200, each of the planet gears254meshes with the third sun gear249at an interior mesh point of the mesh points251and meshes with a ring gear258at an exterior mesh point of the mesh points251. Again, the housing of the third stage210can include a planetary ring gear258that is mounted to a housing236, as shown.

The planet gears254of the third stage210can be mounted to a third planetary carrier257, as mentioned above, using rotary bearings253that allow the planet gears254to rotate freely within the third planetary carrier257while causing the third planetary carrier257to rotate.

In this example, the third planetary carrier257is coupled to a milling tool body261such that the two components rotate at the same speed. As shown, the milling tool body261can be supported on either side with one or more rotary bearings259that allow the milling tool body261to rotate within the housing236of the tool. The rotation of the milling tool body261in the rotation direction205causes the milling face212to rotate such that it can perform milling operations. For example, the bits of the milling face212can be brought into contact with material, such as a portion of a pipe or a valve, and the milling face212can remove material with a milling operation.

FIG.3shows an example schematic of a stand-alone debris collection device, in accordance with embodiments of the disclosure. In an example, a device depicted by diagram300can have a relatively powerful pump that circulates well fluids through a collection bailer (which can serve as separation and storage tank) that separate the fluids from any solids that these fluids may carry. In some respects, solids can be deposited inside the bailers, which can be brought to surface when full. The pump of the debris collection device can also be driven by an electric motor through a gear train. In some aspects, the gear train needed for debris collection may have fewer stages compared to a corresponding gear train needed for milling, at least because the fluid pump may not require as much torque as is needed for milling, as described below.

In particular, diagram300includes a schematic of an embodiment of a device that can be configured to perform debris collection operations in which a motor304(e.g., an electric motor that is powered via an electrical connection302) can drive a fluid pump312through a gear train307(e.g., a two-stage gear train, to be described below). Further, the fluid pump312can circulate fluid through a milling bailer314, which is shown as a tank.

In some respects, the gear train307can include a first stage306and a second stage308. The gear train307can include a first rotational input303at the first stage306. The second stage308can be coupled to the first stage306and can be configured to modify the torque and/or power of the first stage306accordingly, and thereby transmit a predetermined amount of power and energy to rotate and power the fluid pump312and the milling bailer314to perform a debris collection operation via fluid flow.

In more detail, the first rotational input303at the first stage306can be a shaft317coupled to a sun gear319. The sun gear319can be central gear that is fixed to the input shaft317such that it rotates at the same speed as the shaft317. The sun gear319, in turn, is coupled to at least two planet gears334on opposing sides of the sun gear319. Although only two planet gears are shown, the assembly can include more than two planet gears. Further, only one of the pair of planetary gears are labeled in the diagram300to reduce clutter in the diagram. As shown in the diagram300, each of the planet gears334meshes with the sun gear319at an interior mesh point of the of the mesh points331and meshes with a ring gear335at an exterior mesh point of the mesh points331. In this example the ring gear335is fixed relative to the debris collection tool. For example, the ring gear335can be mounted to a housing336of the debris collection tool, as shown.

The diagram300also includes a planetary carrier327spanning the first stage306and second stage308upon which the planet gears334are mounted. In this example, the planet gears334are mounted using a rotary bearing333that allows the planet gears334to rotate freely with respect to the planetary carrier327. The movement of the planet gears334about the sun gear thereby causes the planetary carrier327to rotate. The rotational movement of the planetary carrier327is thereby converted to and serves as second rotational input to the second stage308.

In more detail, the second rotational input (i.e., the rotational movement of the planetary carrier327) at the second stage308can be coupled to a sun gear329of the second stage308. For example, rather than being coupled to a shaft317as explained with the sun gear319of the first stage306, the sun gear329of the second stage308can be coupled to the planetary carrier327of the first stage306. The sun gear329of the second stage308, in turn, can mesh with at least two planet gears344on opposing sides of the second rotational input. Although only two planet gears344are shown, the assembly can include more than two planet gears. As shown in the diagram300, each of the planet gears meshes344with the sun gear329of the second stage308at an interior mesh point of the mesh points341and meshes with a ring gear346at an exterior mesh point of the mesh points341. Again, the housing of the second stage308can be a planetary ring gear that is mounted to a housing336, as shown, containing the planet gears344and providing an exterior mesh point341for the planet gears344. The planet gears344can be mounted to a second planetary carrier347using rotary bearings343, such that the planet gears344can rotate within the rotary bearings343, but rotational movement of the center of the planet gears344around the sun gear329causes the second planetary carrier347to rotate.

The rotational movement of the second planetary carrier347provides a third rotational input to the third stage310. The second planetary carrier347can span the second stage308and third stage310, either directly or by being coupled to a rotational body361used as an input for the pump312. The rotational body361can be positioned inside the housing336of the tool, supported on either side with one or more rotary bearings359that allow the rotational body361to rotate within the housing336. The rotational movement of the rotational body361is coupled to the pump as an input, thereby converting the rotational movement to an input to the pump312. In particular, the rotation of the second planetary carrier347can directly rotate and power the pump312, for example, as shown via the direction of rotation indicator305. As noted, the fourth rotational input can thereby transmit a predetermined amount of power and energy to rotate and power the fluid pump312and the milling bailer314to perform a debris collection operation via fluid flow at aperture316. As shown, the fourth rotational input can turn the fluid pump312due to its connection at fixed joints. Further, the rotation of the fluid pump312can rotate the bailer314.

Using the rotational input described above, the pump312can circulate fluid and filter out debris. For example, fluid can be ingested into a bailer314at an inlet316located at a distal end of the bailer314. The fluid can then be pulled through the pump312and ejected outward from the tool, as shown by the solid arrows in diagram300. One or more filters can be place inside the bailer314, such that debris remains inside the bailer314while fluid flows through the bailer314and then through the pump312. As shown in the diagram, in this example, neither the pump housing nor the bailer314rotates with respect to the tool housing336.

FIGS.4and5shows related embodiments of a combined milling and debris collection device, and in which additional portions of the entire device, including the milling bailer (to be shown and described), rotates. Such embodiments allow for the use of relatively simple bailers to be used in connection with the device that can be substantially similar and/or identical to bailers used with a stand-alone debris removal device such as that shown and described in connection withFIG.3, above. In addition, the disclosed embodiments can enable a stand-alone milling device such as that shown and described in connection withFIG.2, above, to be converted to a combined milling and debris collection device by modifying a last stage of the stand-alone milling device's three-stage gear train (such as the third stage210of gear train207ofFIG.2), as further shown and described below. Such embodiments can enable the ease of adoption of milling and debris removal devices in the field. Further, the gear train can include a planetary gear system in which the drive power from the motor connects to the sun gear of the gear system. The sun gear then drives the planetary gears assembled with the external gear ring to operate. The planetary gear system can revolve on its own axis.

FIG.4shows an example schematic of a first embodiment of a combined milling and debris collection device, in accordance with embodiments of the disclosure. In particular, diagram400shows an embodiment in which, a third stage410of the gear train407can include a three-stage planetary gear box that is modified to have two outputs, described below. The tool ofFIG.4is attached to a wireline402that can be used to raise and lower the tool within the well.

A first output of the gear box can be directly connected to the input of a pump412, such as a portion of the pump coupled to an impeller. This first output can have a relatively high RPM and can drive the fluid pump412. Further, the gear train407can be driven by a single input411from the motor404.

The second output can have a relatively lower RPM but higher torque in comparison with the first rotational output. The second output can be coupled to a rotatable housing487portion of the tool, which in turn can be connected to the fluid pump housing413, the milling bailer414, and the bit face416. Thus, the entire milling bailer414portion of the tool can rotate. Further, as shown in diagram400, both first and second outputs from the gear train407spin in the same direction, as indicated by rotation direction indicators403and405. Accordingly, since the fluid pump's412input has higher RPM than the pump housing413, the fluid pump412operates at the difference between the two RPM values.

In some aspects, the milling bailer414can include a bailer portion shaped to intake fluid proximate a distal end of the bailer portion and allow the fluid to flow through a filter (not shown) and through the fluid pump412,413. Further, the milling bailer414can include a milling face416proximate the distal end of the bailer portion, the milling face416including at least one bit for milling and configured to perform a milling operation while fluid is flowing through the bailer portion. Further, in other aspects, the distal end of the bailer portion can include an aperture423in the milling face416that allows the fluid to enter an interior portion of the bailer portion.

In more detail, the first rotational input403at the first stage406can be a shaft417coupled to a sun gear419. The sun gear419can be central gear that is fixed to the input shaft from the motor404such that it rotates at the same speed as the shaft. The sun gear419, in turn, is coupled to at least two planet gears434on opposing sides of the sun gear419. Although only two planet gears are shown, the assembly can include more than two planet gears. As shown in the diagram400, each of the planet gears434meshes with the sun gear419at an interior mesh point of the mesh points431and meshes with a ring gear435at an exterior mesh point of the mesh points431. In this example, a housing436can include a fixed planetary ring gear435that is mounted to the housing436, as shown.

The diagram400also includes a first planetary carrier427spanning the first stage406and second stage408upon which the planet gears434are mounted. In this example, the planet gears434are mounted using a rotary bearing433that allows the planet gears434to rotate freely with respect to the planetary carrier427. The movement of the planet gears434about the sun gear thereby causes the planetary carrier427to rotate. The rotational movement of the planetary carrier427is thereby converted to and serves as second rotational input to the second stage408.

In more detail, the second rotational input (i.e., the rotational movement of the planetary carrier427) at the second stage408can be coupled to a sun gear429of the second stage408. For example, rather than being coupled to a shaft as explained with the sun gear429of the first stage406, the sun gear429of the second stage408can be coupled to the planetary carrier427of the first stage406. The sun gear429of the second stage408, in turn, can mesh with at least two planet gears444on opposing sides of the second rotational input. Although only two planet gears are shown, the assembly can include more than two planet gears. Further, only one of the pair of planetary gears are labeled in the diagram400to reduce clutter in the diagram. As shown in the diagram400, each of the planet gears444meshes with the sun gear429of the second stage408at an interior mesh point of the mesh points441and meshes with a ring gear446at an exterior mesh point of the mesh points441. Again, the housing of the second stage408can be a planetary ring gear446that is mounted to a housing436, as shown, containing the planet gears444and providing an exterior mesh point441for the planet gears444. The planet gears444can be mounted to a second planetary carrier437using rotary bearings443, such that the planet gears444can rotate within the rotary bearings443, but rotational movement of the center of the planet gears444around the sun gear429causes the second planetary carrier437to rotate. The rotational movement of the second planetary carrier437provides a rotational input to the third stage410.

The second planetary carrier437can couple to a shaft449that spans the second stage408and third stage410. The shaft449can couple to a third sun gear439arranged as part of a third planetary gear box stage410, such that rotation of the shaft449provides equivalent rotation of the third sun gear439. The shaft449can also extend beyond the third sun gear439, as shown, extending through a rotational bearing464mounted to a fixed portion of the housing436. The shaft449can be coupled to the pump412,413, or more specifically the portion of the pump that drives the pump, such as an impeller, referred to herein as the pump input412. In this manner, rotation of the shaft449can cause rotation of the pump input412, such as by driving an impeller.

The third sun gear439at the third stage410, which is driven by the shaft449, can also be coupled to at least two planet gears454using gear mesh connections. Although only two planet gears are shown, the assembly can include more than two planet gears. Further, only one of the pair of planetary gears are labeled in the diagram400to reduce clutter in the diagram. As shown in the diagram400, each of the planet gears454meshes with the third sun gear439at an interior mesh point of the mesh points451and meshes with a ring gear455at an exterior mesh point of the mesh points451.

In the first and second stages406,408, each stage utilizes a ring gear that is mounted to a fixed housing436. However, in the third stage410, the ring gear455is mounted to a rotatable housing487. The rotatable housing487mounts to the fixed housing436at a variety of coupling points, such as a rotary seal457around the shaft449, a rotary seal483where an external portion of the fixed housing436meets the rotatable housing487, and two rotary bearings463, each of which is mounted to a portion of the fixed housing436located internally relative to the rotatable housing487as shown.

In this example, the fixed housing436extends into the third stage410. Fox example, the fixed housing436holds the planet gears454in place, rather than using a gear carrier as in the first and second stages406,408. Because the fixed housing436does not rotate, and the planet gears454are mounted to the fixed housing by way of rotary bearings453, the rotation of the third sun gear439causes rotation of the planet gears454but does not change the position of the planet gears454. That is, the planet gears454do not rotate about the third sun gear439as in the first and second stages406,408. Instead, the planet gears454interface with a ring gear455at the exterior mesh points451, causing the ring gear455itself to rotate. In this example, the ring gear455is mounted to the rotatable housing487, such that any rotation of the ring gear455causes similar rotation of the rotatable housing487.

The rotatable housing487can be coupled to various other components of the tool. For example, as shown inFIG.4, the rotatable housing487is coupled to a pump housing413of the fluid pump. The pump housing413can be any portion of the pump aside from the pump input412; for example, the pump housing413can be a shell that surrounds an impeller. Rotation of the pump input412and pump housing413, relative to one another, can cause the pump to move fluid. For example, the pump input412can remain still while the pump housing413rotates in order to pump fluid. Similarly, the pump input412can rotate while the pump housing413remains still, and the pump will move fluid. In another example, the pump input412and pump housing413rotate at different speeds, causing the pump to operate based on the speed differential.

By way of operating the pump412,413, the tool can then pull fluid into a milling bailer414, such as through an orifice423proximate the distal end of the milling bailer414. The fluid can pass through one or more filters within the milling bailer414to remove debris. The filtered fluid then enters the pump412,413and is expelled out of the pump housing413.

At the same time that the pump412,413is operating to filter the surrounding fluid, the milling bailer414can also be performing a milling operation. For example, the rotatable housing487of the tool can also be coupled to the milling bailer414. In the example ofFIG.4, the rotatable housing487is coupled to the milling bailer414via the pump housing413, such that the rotatable housing487rotates the pump housing413, which rotates the milling bailer414. In other examples, the rotatable housing487can be shaped to directly couple to the milling bailer414. In both examples, rotation of the rotatable housing487translates into rotation of the milling bailer414. The milling bailer414includes one or more bits416on the distal end, such that when the rotating bits come into contact with a material, such as metal, the bits remove a portion of the material to produce a milling effect.

FIG.5shows another example schematic of another embodiment of a combined milling and debris collection device, in accordance with embodiments of the disclosure. In this embodiment, like the embodiment shown in diagram400described above, a third stage510of the gear train507can include a planetary gearbox that is modified to have two rotational outputs, that is, a first rotational output and second rotational output, which can be connected and configured in a similar but not identical manner as described above to respective input505, fluid pump512, and fluid pump housing513. However, in this embodiment the two outputs can spin in directions opposite to each other, as indicated by direction of rotation indicators511and515. This increases the RPM difference, which may be preferable if the fluid pump512requires relatively high RPM to operate. In this embodiment as with the embodiment described above, the entire milling bailer514tool rotates.

In more detail, a first output of the gear box can be directly connected to the input of a pump512, such as a portion of the pump coupled to an impeller. This first output can have a relatively high RPM and can drive the fluid pump512,513. Further, the gear train507can be driven by a single input from the motor504. The tool ofFIG.5is attached to a wireline502that can be used to raise and lower the tool within the well.

The second output can have a relatively lower RPM but higher torque in comparison with the first rotational output. The second output can be coupled to a rotatable housing587portion of the tool, which in turn can be connected to the fluid pump housing513, the milling bailer514, and the bit516. Thus, the entire milling bailer514portion of the tool can rotate. Further, as shown in diagram500, both first and second outputs from the gear train507spin in the opposite direction, as indicated by rotation direction indicators511and515. In an example where the pump input512and the pump housing513rotate at different speeds (e.g., different RPM), the differential between those rotational speeds will drive the pump512,513.

In some aspects, the milling bailer514can include a bailer portion shaped to intake fluid proximate a distal end of the bailer portion and allow the fluid to flow through a filter (not shown) and through the fluid pump512,513. Further, the milling bailer514can include a milling face516proximate the distal end of the bailer portion, the milling face516including at least one bit for milling and configured to perform a milling operation while fluid is flowing through the bailer portion. Further, in other aspects, the distal end of the bailer portion can include an aperture523in the milling face516that allows the fluid to enter an interior portion of the bailer portion.

In more detail, the first rotational input505at the first stage506can be a shaft517coupled to a sun gear519. The sun gear519can be central gear that is fixed to the input shaft517from the motor504such that it rotates at the same speed as the shaft517. The sun gear519, in turn, is coupled to at least two planet gears534that mesh with the sun gear519. Although only two planet gears are shown, the assembly can include more than two planet gears. As shown in the diagram500, each of the planet gears534meshes with the sun gear519at an interior mesh point of the mesh points531and meshes with a ring gear535at an exterior mesh point of the mesh points531. In this example, a housing536can include a fixed planetary ring gear535that is mounted to the housing536, as shown.

The diagram500also includes a first planetary carrier527spanning the first stage506and second stage508upon which the planet gears534are mounted. In this example, each planet gear is mounted to the carrier527using a rotary bearing533that allows the planet gears to rotate freely with respect to the planetary carrier527. The movement of the planet gears534about the sun gear519thereby causes the planetary carrier527to rotate. The rotational movement of the planetary carrier527is thereby converted to and serves as second rotational input to the second stage508.

In more detail, the second rotational input (i.e., the rotational movement of the planetary carrier527) at the second stage508can be coupled to a sun gear529of the second stage508. For example, rather than being coupled to a shaft as explained with the sun gear519of the first stage506, the sun gear529of the second stage508can be coupled to the planetary carrier527of the first stage506. The sun gear529of the second stage508, in turn, can mesh with at least two planet gears544. Although only two planet gears are shown, the assembly can include more than two planet gears. As shown in the diagram500, each of the planet gears544meshes with the sun gear529of the second stage508at an interior mesh point of the mesh points541and meshes with a ring gear545at an exterior mesh point of the mesh points541. Again, the housing of the second stage508can be a planetary ring gear545that is mounted to a housing536, as shown, containing the planet gears544and providing an exterior mesh point541for the planet gears544. The planet gears544can be mounted to a second planetary carrier537using rotary bearings543, such that the planet gears544can rotate within the rotary bearings543, but rotational movement of the center of the planet gears544around the sun gear529causes the second planetary carrier537to rotate.

The rotational movement of the planetary carrier537is then converted to third rotational input to the third stage510. For example, the second planetary carrier537can couple to a shaft549that spans the second stage508and third stage510. The shaft549can couple to a third sun gear539arranged as part of a third planetary gear box stage510, such that rotation of the shaft549provides equivalent rotation of the third sun gear539. The shaft549can also extend beyond the third sun gear539, as shown, extending through rotational bearings564. The shaft549can be coupled to the pump512,513, or more specifically the portion of the pump that drives the pump, such as an impeller, referred to herein as the pump input512. In this manner, rotation of the shaft549can cause rotation of the pump input512, such as by driving an impeller.

The third sun gear539at the third stage510, which is driven by the shaft549and/or the second carrier537, can also be coupled to at least two planet gears554using gear mesh connections. Although only two planet gears are shown, the assembly can include more than two planet gears. Further, only one of the pair of planetary gears are labeled in the diagram500to reduce clutter in the diagram. As shown in the diagram500, each of the planet gears554meshes with the third sun gear539at an interior mesh point of the mesh points551and meshes with a ring gear555at an exterior mesh point of the mesh points551.

The planet gears554can be mounted to a third planetary carrier547by way of rotational bearings553. The rotational bearings553allow the planet gears554to rotate relative to the third planetary carrier547, while the movement of the planet gears554about the sun gear539causes the third planetary carrier547to rotate. In this example, the third planetary carrier547is fixed to—or alternatively, formed as part of—a rotatable inner housing557. The rotatable inner housing557is configured such that it can rotate within, and with respect to, the fixed housing536of the tool. For example, the fixed housing536can support the rotatable inner housing557using rotational bearings563that surround the rotatable inner housing557and are mounted within the fixed housing536. The fixed housing536can also prevent fluid or debris from penetrating between the housing536and the rotatable inner housing557by using a rotary seal559, as shown in the diagram500.

The rotatable inner housing557can be configured such that it is rigidly coupled to a rotatable housing587that extends away from the fixed housing536of the tool. In some examples, rather than being rigidly coupled to one another, the rotatable inner housing557and rotatable housing587are formed as one piece that rotates together. In either example, rotation of the rotatable inner housing557can translate directly to rotation of the rotatable housing587.

As shown, the rotatable inner housing557can extend through at least a portion of the rotatable housing587. Additionally, the rotatable inner housing557can support the shaft549that serves as an input to the pump input512.

The rotatable housing587, in turn, can include a pump housing513. The pump housing513can be any portion of the pump aside from the pump input512; for example, the pump housing513can be a shell that surrounds an impeller. Rotation of the pump input512and pump housing513, relative to one another, can cause the pump to move fluid. For example, the rotatable housing587can be coupled to the pump housing513by way of fasteners or welding, or can be formed together with the housing513in some examples. In either case, rotation of the rotatable housing587can cause equivalent rotation of the pump housing513. As mentioned above, the pump input512can be driven by a shaft549, which rotates at a different rate relative to the pump housing513. This differential in rotational speeds can drive the pump512,513.

The rotatable housing587and/or the pump housing513can be coupled to various other components of the tool. For example, as shown inFIG.5, the rotatable housing587is coupled to a pump housing513of the fluid pump, which is then rigidly coupled to a milling bailer514, such as by using fasteners or welding. Therefore, rotation of the rotatable housing587translates into a same-speed rotation of the milling bailer514. This can be accomplished by rigidly coupling the rotatable housing587directly to the milling bailer514in some examples (not shown).

By way of operating the pump512,513, the tool can then pull fluid into the milling bailer514, such as through an orifice523proximate the distal end of the milling bailer514. The fluid can pass through one or more filters within the milling bailer514to remove debris. The filtered fluid then enters the pump512,513and is expelled out of the pump housing513.

At the same time that the pump512,513is operating to filter the surrounding fluid, the milling bailer514can also be performing a milling operation. For example, the rotatable housing587of the tool can also be coupled to the milling bailer514. In the example ofFIG.5, the rotatable housing587is coupled to the milling bailer514via the pump housing513, such that the rotatable housing587rotates the pump housing513, which rotates the milling bailer514. In other examples, the rotatable housing587can be shaped to directly couple to the milling bailer514. In both examples, rotation of the rotatable housing587translates into rotation of the milling bailer514. The milling bailer514includes a bit face516on the distal end having one or more bits, such that when the rotating bits come into contact with a material such as metal, the bits remove a portion of the material to produce a milling effect.

As noted, the disclosed systems as shown and described above (e.g., with respect toFIGS.4and5) include a device that has a dual-output stage of a gear train. In some respects, the planetary gear trains described above can be configured such that the planetary carrier portion rotates in either direction based on the configuration of the intermediate planet gears. In such a device, one of the outputs can drive the fluid pump, while the other output rotates the entire debris collection tool, to which a bit is attached. This allows the device to avoid the use of a specialized bailers specific to this service; rather, a standard milling bailer that exists in the field can be reused. Further, the gear train of milling tools are modified in a relatively simplified manner to execute the functionality described herein.

FIG.6shows an example flow chart illustrating some example operations of a method for performing simultaneous milling and debris collection, in accordance with embodiments of the disclosure, with each block representing a stage of an example method. At block602, a tool can be provided. The tool may be attached to a suitable well access line such as a wireline cable, a length of coiled tubing, or the like. The well access line can extend downhole from a surface of the wellbore and is in communication with surface equipment, control equipment, and the like for communication of power, telemetry and control signals. A user can direct operation of the tool including setting a target torque value, setting a push force limit value, starting rotation of the bit and starting a milling or drilling operation. Stage602can also include providing a tool as described above, particularly with respect to the embodiments ofFIGS.4and5.

At block604, the tool can be lowered down a well using the wireline. The tool can be deployed into the well on the well access line (e.g., the wireline) and maneuvered into a desired location within the well. At block606, the tool can be positioned such that the milling face is in contact with a surface to be milled. In some wells, such as horizontal or deviated wellbores or the like, additional modules may be utilized to position the tool to the desired location, for example, by engaging with the walls of the well. The tool can provide a signal (e.g., an electrical signal) to a user that the milling surface has contacted the surface to be milled. At block608, the motor can be operated such that the milling bailer rotates, causing the milling face to mill the surface while fluid flows through the milling bailer portion to the fluid pump. During operation of the tool, an electronics module can control the speed of the motor, and phase current samples from the motor can be used to control the torque output of the motor. Based on the phase current samples, firmware in the electronics module can calculate respective torque values experienced on the shaft of the motor. The calculated torque values can be used to report real-time torque measurements to the surface via a telemetry cartridge or the like. This calculated torque value is also used to request push force adjustment from the electronics module.

An example method, such as the method ofFIG.6, can also include retrieving the tool from the well and performing cleaning or maintenance operations. For example, the debris collection operation of the tool can cause a build-up of debris collected within a bailer portion of the tool. An example method can include cleaning this debris from the bailer, such as by removing one or more filters within the bailer for cleaning, or by pumping cleaning fluid through the bailer in a flow direction opposite the normal debris-collection direction.

The preceding description has been presented with reference to present embodiments. Persons skilled in the art and technology to which this disclosure pertains will appreciate that alterations and changes in the described structures and methods of operation can be practiced without meaningfully departing from the principle, and scope of this invention. Accordingly, the foregoing description should not be read as pertaining only to the precise structures described and shown in the accompanying drawings, but rather should be read as consistent with and as support for the following claims.