RU2663007C1 - Single-pass mill unit - Google Patents

Abstract

FIELD: technological processes.SUBSTANCE: group of inventions relates to method and systems for milling a guide window in a casing string. Method for milling a guide window in a casing string includes the steps of: introducing a milling assembly comprising a deflecting tool, inside the first wellbore and the first operating mode of the said milling assembly is used to create a guide window in the casing of said first wellbore. Then, the said deflecting tool is fixed in said first wellbore and a second mode of operation of said milling assembly is used to start the second wellbore through said guiding window.EFFECT: technical result consists in reduction of the drilling time.20 cl, 5 dwg

Description

BACKGROUND

The present invention relates generally to well drilling operations, and more particularly, to a single-pass milling unit for multi-barrel well systems.

During drilling operations, it may be necessary to drill a lateral wellbore from an existing cased wellbore or to change the path of a wellbore after a casing has been installed. Often in such cases, before drilling a sidetrack, operators at the well site use the first router to create a guide window in the casing, and then the second router to create a small branch of the wellbore that starts the sideway. Typically, this requires multiple trips on the drill string through the wellbore, which can be costly and time consuming.

BLUEPRINTS

The following is a description of some specific exemplary embodiments of the invention, which will be better understood by reference to the accompanying drawings.

FIG. 1 is a diagram illustrating an offshore oil and gas platform that can utilize a typical single pass mill system in accordance with aspects of the present invention.

FIG. 2 is a flowchart illustrating an example of a single pass milling method according to aspects of the present invention.

FIG. 3A-3D are diagrams illustrating a flowchart for using an exemplary single pass mill assembly in accordance with aspects of the present invention.

FIG. 4A and 4B are diagrams illustrating a first mode of operation of a single pass mill assembly according to aspects of the present invention.

FIG. 5A-5C are diagrams illustrating the movement of an annular mill and an offset column during a first mode of operation of a single pass mill assembly according to one or more embodiments of the invention.

While embodiments of the present invention are illustrated, described and determined by reference to typical embodiments of the invention, such references do not imply a limitation of the invention, and no such limitation should be assumed. An object of the described invention can undergo significant modifications, changes and equivalents in form and function, which can be performed by a person skilled in the art due to this description. The illustrated and described embodiments of the present invention are only examples and do not provide comprehensive information about the scope of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates generally to well drilling operations, and more particularly, to a single-pass milling unit for multi-barrel well systems.

Illustrative embodiments of the present invention are described in detail herein. For clarity, not all features of the actual implementation may be described in this document. Of course, it should be understood that in the development of any such actual embodiment of the invention, numerous implementations of specific solutions must be implemented in order to achieve specific implementation goals, which will differ from one implementation to another. In addition, it should be borne in mind that such a development can be complex and time-consuming, but, nevertheless, due to the description of the present invention, understandable to a person skilled in the art.

The terms “connects” or “connects” as used herein mean either indirect or direct connection. Thus, if the first device is connected to the second device, then such a connection can be made by direct connection or by indirect electrical or mechanical connection through other devices and connections. The term “upstream” as used herein means along the flow path towards the source of the flow, and the term “downstream” used herein means along the flow path in the direction from the flow source. The term “uphole” as used herein means along the drill string or borehole from the far end towards the surface, and “downhole” as used herein means along the drill string or well from the surface towards the far end.

It should be understood that the terms “oil well drilling equipment” or “oil well drilling system” are not intended to limit the use of equipment and processes described using these terms for drilling an oil well. In general, the terms also include the drilling of natural gas or hydrocarbon wells. In addition, such wells can be used for production, control or injection in relation to the extraction of hydrocarbons or other materials from the lower horizons. They may also include geothermal wells designed to produce a heat source, instead of hydrocarbon ones.

For the purposes of this description, an information processing system may comprise any technical means or a combination of technical means configured to calculate, classify, process, transmit, receive, extract, create, commute, store, display, implement, detect, record, reproduce, process or the use of any kind of information, artificial intelligence or data for commercial, scientific, control or other purposes. For example, the information processing system may be a personal computer, a network storage device, or any other suitable device that may vary in size, shape, performance, functionality, and price. The information processing system may include random access memory (“RAM”), one or more computing resources, such as a central processor (“CPU”) or hardware or software controlled logic, ROM and / or other types of non-volatile memory. The information processing system may further comprise a microcontroller, which may be a minicomputer on a single integrated circuit containing a processor core, memory and programmable peripheral input / output devices. Additional components of the information processing system may include one or more disk drives, one or more network ports for communication with external devices, as well as various input and output devices (“input / output”), such as a keyboard, mouse, and video display. The information processing system may also contain one or more buses, configured to implement communication between various hardware components.

For the purposes of this description, computer-readable media may contain any hardware or a combination of hardware that can store data and / or commands for a certain period of time. Computer-readable media may include, for example, without limitation, data storage media such as direct access storage device (e.g., hard disk or floppy disk), sequential access storage device (e.g., tape drive), CD, CD-ROM, DVD, RAM, ROM, electrically erasable programmable ROM (“EEPROM”) and / or flash memory; as well as communications such as wires.

For a better understanding of this description, examples of specific embodiments of the invention are given below. In no way should the examples below be construed as limiting or defining the scope of the invention. Embodiments of the present invention can be applied to horizontal, vertical, inclined, multi-barrel, U-shaped, intersected, bypassed (drilled around a tool tucked into the borehole at an average depth and back into the borehole below) or other nonlinear boreholes in the underground reservoir of any type. Embodiments of the invention may be applicable to injection wells and production wells, including production wells for the extraction of natural resources such as hydrogen sulfide, hydrocarbons or geothermal wells; and in the construction of a borehole for tunneling through rivers and other similar tunnel boreholes for the construction of subsurface or borehole U-shaped pipelines used to transport fluids such as hydrocarbons. Embodiments of the invention described below with respect to one implementation are not limiting.

FIG. 1 illustrates an offshore oil and gas production platform 100 that can utilize an exemplary single pass mill system as described herein, according to one or more embodiments of the invention. Although FIG. 1 illustrates an offshore oil and gas production platform 100, one skilled in the art will appreciate that the various embodiments described herein are equally well suited for use with other types of oil and gas rigs, such as onshore oil and gas rigs or drilling rigs located in any other geographical location. However, in the illustrated embodiment, the platform 100 may be a semi-submersible platform 102 mounted above the subsea oil and gas formation 104 located below the seafloor 106. An underwater riser or channel 108 extends from deck 110 of the platform 102 for installation at the wellhead 112 located on the seafloor 106 and containing one or more blowout preventers 114. The platform 102 has a lifting device 116 and a drilling tower 118 for raising and lowering a pipe string, such as a drill pipe string 120, located ennaya inside the underwater channel 108.

As illustrated, the main wellbore 122 is drilled through various strata of the earth, including formation 104. The terms “parent” and “main” wellbore are used interchangeably herein to refer to the wellbore from which another wellbore has been drilled. However, it should be noted that the parent or main wellbore does not necessarily extend to the surface of the earth, and, instead, may be a branch of another wellbore. The casing 124 is at least partially cemented within the main wellbore 122. The term “casing” is used herein to mean a pipe string used to align the wellbore. In some applications, the casing may be of a type known to those skilled in the art as a “liner” and may be a segmented liner or a continuous liner, such as a tubing string.

As illustrated, a branch or lateral wellbore 128 may be drilled in accordance with one or more embodiments of the single pass mill system and method of operation described below. The terms “branch” and “side” wellbore are used herein to mean a wellbore that is drilled outward from its intersection or merging with another wellbore, such as the parent or main wellbore 122. In addition, without departing from the scope of the invention, the branch or lateral wellbore may have another branch or lateral wellbore drilled outward from it. The casing joint 126 may interconnect elongated portions or sections of the casing 124 and be located at the desired location within the borehole 122, where a branch or sidetrack 128 has been drilled. Accordingly, the casing joint 126 effectively forms an integral part of the casing 124.

A retractable deflecting wedge assembly 130 or another type of milling guide shoe known to one skilled in the art may be located within the casing 124 and / or casing joints 126. The retractable deflecting wedge 130 assembly may be configured to facilitate one or more cutting tools ( that is, milling cutters) in creating an exit from the casing 132 on the inner wall of the connection of the casing 126 in the right place around the periphery. The exit from the casing 132 provides a “window” in the connection of the casing 126 through which one or more other cutting tools (i.e., drill bits) can be inserted to drill the side bore 128.

One of ordinary skill in the art will understand that although FIG. 1 illustrates a vertical section of a main wellbore 122, embodiments of the invention described herein are equally applicable for use in wellbores having other directional configurations, including horizontal wellbores, curved wellbores, deviated wellbores, combinations thereof, and the like. like that. In addition, terms relating to direction, such as higher, lower, upper, lower, up, down, up the borehole, down the borehole and the like, are used with reference to illustrative embodiments of the invention as depicted in the figures, those. the upward direction will be towards the top of the corresponding figure, and the downward direction will be towards the bottom of the corresponding figure, the upward direction of the wellbore will be towards the surface of the well and the downward direction of the well will be towards the bottom of the well.

FIG. 2 is a flowchart illustrating an example of a single pass milling method 200, as described herein, in accordance with one or more embodiments of the invention. At step 210, a single-pass router assembly can be inserted into the wellbore (such as wellbore 122 in the embodiment of FIG. 1).

At step 220, a single-pass milling unit assembly may be secured within the wellbore. The single-pass router assembly can be axially and radially fixed in the casing (such as casing 124 in the embodiment of FIG. 1), at a suitable and most effective depth and orientation for the desired location of the guide window in the casing. The outer column of the single pass mill assembly can act as a platform for creating a guide window. An anchor can be used to fasten the single-pass milling unit, which can contain various tools and interconnected tubular sections to rotate and align the milling tool (both radially and axially) with respect to the orientation of the exit angle and the axial depth of the borehole of the desired guide window. In some embodiments of the invention, the Sperry multi-barrel attachment or connection system available from Halliburton Energy Services, Inc., Houston, Texas, USA, may be an anchor. In other embodiments of the invention, the guide shoe may be an anchor with a combination of motion and shear blocking, or any other mechanical means known to a person skilled in the art for installing a single-pass milling unit both at a certain depth inside the main wellbore and at the desired orientation of the exit angle.

At step 230, the first mode of operation of the single-pass mill assembly can be used to cut a guide window in the casing (such as casing 124 in the embodiment of the invention of FIG. 1). The guide window may be an opening of a predetermined size, geometry, location and orientation (such as the exit from the casing 132 in the embodiment of the invention of FIG. 2). In some embodiments of the invention, a guide window may be used to change the path of an existing wellbore after a casing has been installed. In other embodiments, the guide window may be used as a branch point for drilling a new side wellbore (such as side well 128 in the embodiment of FIG. 1) from the parent wellbore.

At 240, the locking mechanism may be released to allow the outer string of the single pass mill assembly to descend into the well, and the deflecting tool (such as the retractable deflecting wedge 130 in the embodiment of FIG. 1) may be secured to the wellbore so as to align the deflection angle of the deflecting tool relative to the guide window. The deflecting tool may be secured using any of the means described with respect to step 220, such as the multi-barrel attachment system or Sperry joints, to rotate and align the deflecting tool (both radially and axially) with respect to the guide window.

At step 250, the second mode of operation of the single-pass router assembly can be used to start the side wellbore from the guide window cut in step 220. In some embodiments of the invention, the start of creating the side wellbore may include cutting a borehole branch (for example, an 8-12 meter well which can be used as a source and / or guide for subsequent drilling). Optionally, this step may include expanding the guide window cut in step 230.

At step 260, the single-pass milling unit can be removed to the surface, while the deflecting tool installed earlier at step 240 remains fixed (in the axial and radial direction) in the well. A fixed diverting tool can provide an efficiently oriented outlet for conventional drilling systems to complete the side wellbore (eg, a borehole branch) started at step 250. In alternative embodiments of the invention, sidetracking can be continued using a single-pass milling unit. In some embodiments of the invention, this can be achieved by further using the second mode of operation of the single-pass mill unit, which was used to start the side wellbore (step 250), or, alternatively, with the third mode of operation of the single-pass mill unit.

Stages of a method of an embodiment of the invention FIG. 2 may be performed in a different order than that illustrated in FIG. 2. For example, fixing the deflecting tool in the wellbore (step 240) does not necessarily occur between the use of the first mode of operation of the single-pass mill unit (step 230) and the use of the second mode of operation of the single-pass mill unit (step 250). Thus, in some alternative embodiments of the invention, the fastening of the deflecting tool in the wellbore can be carried out before using the first operating mode (step 230) or after using the second operating mode (step 250).

FIG. 3A-3D illustrate a series of steps for using an exemplary single pass mill assembly 300 according to one or more embodiments of the invention. In exemplary embodiments of the invention of FIG. 3A-3D illustrates a drill pipe string 320 located in a borehole 322 that is drilled into the formation 304 and reinforced by a casing 324. The drill pipe 324 may be connected to the formation 304 through a cement layer 323. In some embodiments of the invention, the drill pipe 320 may comprise an axial milling cutter 350 and, optionally, a barrel-shaped milling cutter 352. The single-pass milling cutter assembly may also comprise a deflecting tool illustrated in FIG. 3A-3D in the form of a recoverable deflecting wedge 330.

In the embodiment of FIG. 3A-3D illustrates a retractable deflecting wedge 330 with an integrated milling system comprising a ring mill 342 and a milling channel 344. In at least one embodiment, the milling system 340 may be a First Pass MILLRITE® system commercially available from Halliburton Energy Services, Inc ., Houston, Texas, USA. However, in other embodiments, the milling system 340 may be any multi-barrel milling system known to one skilled in the art. For example, milling system 340 can be any milling system that is capable of cutting the exit from casing 332 into casing 324 (and optionally cement layer 323) and thereby facilitate drilling into the surrounding subterranean formation 304 to create a side wellbore.

The recoverable deflecting wedge 330 may be coupled to the drill pipe string 320 so that they can be inserted into the well 322 together. In the embodiment of the invention of FIG. 3A-3C, the drill string 320 is connected to a retractable deflecting wedge 330 by means of a sleeve 355 and a shear screw 325. As will be described in more detail below with respect to the embodiment of FIG. 3D, the drill string 320 may be detachable from the retractable deflecting wedge 330. The retractable deflecting wedge may have a stopper 360 for engaging with a first stop position 362 and a second stop position 364 of the casing 324. Thus, the drill string 320 can be used to insert a retractable deflecting wedge 330 into the wellbore 322, set the retractable deflecting wedge 330 to a desired position by interacting with the stopper 360 or with the first stopper position 362, or with a second locking position 364, and the subsequent withdrawal from the wellbore 322, leaving the removable deflecting wedge 330 fixed in place.

In FIG. 3A illustrates a typical single-pass router assembly 300 located in a wellbore 322 with a retractable deflecting wedge 330 installed in a first stop position 362. The first stop position 362 can be located in the well so that when the retractable deflecting wedge 330 is locked in a first stop position 362, the milling system 340 (and, in particular, the annular milling machine 342) may coincide with the desired location for cutting the guide window in the casing 324.

In FIG. 3B illustrates a typical single pass mill assembly 300, which is used in the first mode of operation to force the milling system 340 to cut a guide window 332 in the casing 324 and optionally the cement layer 323. In the illustrated embodiment, where the milling system 340 comprises an annular mill 342 and the milling channel 344, the first mode of operation can cause the annular milling machine 342 to rotate and cut through the casing 324 and the cement layer 323 along the entire length of the milling channel 344. Thus, the guide window 332 may have the required dimensions, geometry, location, and orientation. Although various methods known to a person skilled in the art can be used to achieve the first mode of operation of the single pass mill 300, below, with reference to FIG. 4, an embodiment of the invention using a fluid stream is described in detail.

In FIG. 3C illustrates a typical single pass mill assembly 300 in which the retractable deflecting wedge 330 is moved to the second stop position 364. This movement can be performed by a surface operator pushing or pulling the drill string 324 to release the stop 360 from the first stop position 362 and then reposition the drill string 324 to align the stopper 360 with the second stopper position 364. The second stopper position 364 may be positioned in the well so that when the retractable deflecting wedge 330 is locked in about the second locking position 364, the angle of deviation from the extracted deflecting wedge 330 coincides with the guide window 332 in the casing 324.

In FIG. 3D illustrates a typical single pass mill assembly 300, which is used in a second mode of operation to force an axial mill 350 and a barrel-shaped mill 352 to cut a borehole branch 334 through a guide window 332. And although various methods known to a person skilled in the art can be used to achieve a second mode of operation of the single pass mill assembly 300, an embodiment of the invention illustrated in FIG. 3D can use rotational and downward force from drill pipe 320. In particular, an operator on the surface can cause drill pipe 320 to rotate and move down the wellbore with a force sufficient to force axial milling machine 350 to cut off shear screw 325 and cut sleeve 355. Thus, drill string 320 can be detached from the removable deflecting wedge 330. To facilitate detachment, sleeve 355 may consist of a relatively soft material that can be axially cut a milling cutter 350 (e.g., aluminum), wherein the retractable deflecting wedge 330 may consist of a relatively strong material that cannot be cut through by an axial milling cutter 350 (e.g., carbide).

After cutting through the sleeve 355, the drill string 320 (together with the axial milling cutter 350) can be deflected using a retractable deflecting wedge 330 inside the guide window 322. The continued downward force and rotation of the drill pipe 320 will force the axial milling cutter 350 to cut outside the guide window 332 into the reservoir 304 and create a branch of the wellbore 334. In embodiments of the invention where the drill pipe string 320 further comprises a barrel-shaped milling cutter 352, the second mode of operation of the single-pass assembly th router may also extend the guide window 332 and increase the diameter of the branch wellbore 334.

In some embodiments of the invention, the drill string 320 may rise from the wellbore 322 after cutting through a branch of the wellbore 334, leaving a retractable deflecting wedge 330 in the wellbore. Thereafter, another drillstring configured to drill using drill pipe 32 may be inserted into the wellbore 322 any of various means known to a person skilled in the art. This drill pipe string can be deflected by a retractable deflecting wedge 330 into a branch of a wellbore 334 and then used to drill a side well.

Optionally, the recoverable deflecting wedge 330 may also include mechanisms (not illustrated) to facilitate subsequent extraction using flushing. In some embodiments of the invention, the outer edge of the retractable deflecting wedge 330, in the annular space between the retractable deflecting wedge 330 and the casing 324, may contain an elastomer, such as hydrogenated nitrile butadiene rubber (GBNA). The GBNK may be color-coded so that during flushing operations, the position of the flushing tool relative to the extracted deflecting wedge 330 can be determined by the color of the backflow of the drilling fluid. For example, yellow-colored GBNK can be located near the top of the extracted deflecting wedge 330, resulting in when the flushing tool makes initial contact with the removable deflecting wedge 330 and erases this layer of GBNK, the return flow of the drilling fluid will turn yellow. An orange colored GBNA may be located even lower than the retractable deflecting wedge 330, etc. Thus, the retractable deflecting wedge 330 can be accurately detected and captured by the flushing tool to remove from the wellbore 322.

FIG. 4A and 4B illustrate an exemplary first mode of operation of a single pass mill assembly 400 according to one or more embodiments of the invention. The embodiment of the invention of FIG. 4A and 4B illustrate formation 404, drill pipe 420, well bore 422, cement 423, casing 424, first retaining position 462, shear screw 425, retractable wedge 430, milling system 440, ring milling machine 442, milling channel 444, axial milling cutter 450, barrel milling cutter 452, sleeve 455 and stopper 460, one or more of which may be similar to corresponding elements in the embodiments of the invention of FIG. 3A-3D.

In the embodiment of FIG. 4A and 4B, the milling system 440 further comprises a guide 446 (also known as a "guide block", a "movable guide block", or a "milling block"), which can typically support and guide the ring mill 442 within the retractable deflecting wedge 430. As illustrated, the retractable deflecting wedge 430 may define or otherwise form the milling channel 444. As the annular milling machine 442 moves down the wellbore, the guide 446 moves axially along the milling channel 444, which It may comprise a sloping portion (not illustrated) which gradually urges the rotating annular cutter 442 to the inner surface of the casing 424 and, optionally, the cement layer 423, cutting thus the formation of the guide box. As the annular milling machine 442 moves further down the wellbore, the guide 446 moves along the milling channel 444 and, accordingly, the axial length or opening of the guide window increases until the guide block reaches the end of the milling channel 444. Thus, the interaction of the guide 446 with the milling channel 444 allows you to control the size of the guide window cut through the casing 424 and the cement layer 423.

In the embodiment of FIG. 4A and 4B, a displaceable column 470 may be located within the sleeve 455. A rotary column 480 may be located within the displaceable column 470, which may be coupled to the displaceable column 470 and to the annular milling machine 442. The displaceable column 470 and the rotary column 480 may be held in place by means of an interlock a mechanism 474, which can be coupled to a sleeve 455 or a retractable deflecting wedge 430. In some embodiments of the invention, the rotating column 480 may not be a column separate from the displaced column 470, but instead m Jet be displaceable rotary portion 470 column.

In some embodiments of the first mode of operation of the single-pass milling machine assembly 400, the interlock mechanism 474 can be unlocked, allowing the displaceable string 470 and the rotary string 480 to move down the wellbore. In addition, when shifted down the wellbore, the rotatable string 480 can rotate. In some embodiments of the invention, the conversion of hydraulic energy to mechanical energy can create a force forcing a displaceable string 470 to move down the wellbore, as well as to move down the wellbore and rotate the rotating string 480.

FIG. 4B illustrates one embodiment of the invention in which hydraulic energy may be provided by a fluid stream 490, which may be a mud stream (eg, mud) controlled by a surface operator and pumped down the drill pipe 420. The fluid flow 490 may coupling 455, which can create a pressure drop in the fluid stream 490 by preventing mixing of the fluid stream 490 flowing down the wellbore through the sleeve 455, and the fluid stream 490 flowing up the wellbore through the wellbore 422. Optionally, the sleeve 455 may also include a relatively small diameter portion to maintain or increase this pressure drop.

In FIG. 4B illustrates the pressure from the fluid stream 490 that unlocks the locking mechanism 474. Axial seals 472 may be located in the annulus between the displaced column 470 and the sleeve 455 to prevent the fluid stream 490 from entering the annular space as the displaced column 470 and rotates column 480 is moving down the wellbore. Thus, the pressure differential of the fluid stream 490 can be maintained, and the fluid stream 490 can be directed to the displacement column 470 and, accordingly, to the rotary column 480, as illustrated in FIG. 4B.

In some embodiments of the first mode of operation, the rotary column 480 may include a mechanism for converting hydraulic energy into axial force, such as a mixer 484. The rotary column 480 may also include a mechanism for converting hydraulic energy to torque, such as a power section 486. Thus, the flow of fluid 490 through the rotating column 480, including the agitator 484 and the power section 486, can force the agitator 484 to create a force directed down the borehole, and the power section 486 creates tat torque. The force directed down the borehole generated by the agitator 484 can cause the displaced string 470 and the rotary string 480 to move down the wellbore. Similarly, the torque generated by the power section 486 can cause the rotary string 480 to rotate. Optionally, the rotary string 480 may also include a float valve 482, which may restrict fluid flow 490 to a one-way flow into the rotary column 480 from the displaceable column 470. In some embodiments, this may help maintain lubricated mixer 484 and power section 486 by preventing fluid leakage flow 490 from the rotary columns 480 and biased back into column 470.

As a result of moving down the wellbore and rotating the rotating column 480, the annular milling cutter 442 can also rotate while moving down the borehole along the milling channel 444 until the guide 446 reaches the end of the milling channel 444. Thus, the first mode of operation of the single-pass milling unit 400 may force the annular milling cutter 442 to cut through the guide window in the casing 424, and, optionally, the cement layer 432 along the milling channel 444. The connection between the rotary casing 480 and the annular milling cutter 442 may optionally include a transmission 492 to facilitate smooth transmission of axial and rotational forces from the rotary column 480 to the ring mill 442. Similarly, the connection between the rotary column 480 and the ring mill 442 may optionally include a bearing block 494 to facilitate the smooth rotation of the ring mill 442. In some embodiments, the bearing block 494 may be a fluid lubricated block, and in such embodiments at least some of the fluid stream 490 can be directed through the bearing block 494. In alternate embodiments may use other types of bearings are known to those skilled in the art (e.g., oil bearings).

During cutting, fluid stream 490 can trap rock fragments and return them to the surface by flowing up the borehole through a retractable deflecting wedge 430 and borehole 422. When the guide 446 reaches the end of the milling channel 444, the surface operator may see a drop in pressure drop and, thus, understand that the guide window has been cut through. The surface operator can then stop pumping the fluid and, if desired, proceed to initiate a second mode of operation for the single pass mill 400.

FIG. 5A-5C illustrate the movement of an annular milling machine 542 and an offset column 570 during an exemplary first mode of operation of a single pass milling unit 500 in accordance with one or more embodiments of the invention. The embodiment of the invention of FIG. 5A-5C illustrate a formation 504, a borehole 522, a cement layer 523, a casing 524, a retractable deflecting wedge 530, a milling system 540, an annular milling machine 542, a milling channel 544, a guide 546, a coupling 555, a stop 560, a first stop position 562, axial seals 572, locking mechanism 574, rotating column 580, float valve 582, agitator 584, power section 586, transmission 592 and bearing block 594, one or more of which may be similar to the corresponding elements in the embodiments of the invention of FIG. 4A and 4B.

In the embodiment of FIG. 5A, a ring mill 542 and an offset column 570 are illustrated prior to initializing the first mode of operation. An annular milling cutter 542 located at the beginning of the milling channel 544 is illustrated such that the annular milling cutter 542 does not touch the casing 524. An offset string 570 that has not yet been moved inside the sleeve 555 is illustrated, and the locking mechanism 574 can be locked.

In the embodiment of FIG. 5B, an annular milling cutter 542 and an offset column 570 are illustrated during the first mode of operation. A displaceable string 570 is illustrated which is displaced in a sleeve 555 downstream of a wellbore. Moving the displaced column 570 may cause the annular milling machine 542 to move down the borehole along the milling channel 544. The milling channel 544 may include a first inclined portion 547 to force the annular milling machine 542 to move toward the formation 504 as it passes along the milling channel 544. The first inclined portion 547 may be of sufficient height to force the annular milling cutter 542 to cut through the guide window 532 of the desired depth in the casing 524 and, optionally, the cement layer 523. As also illustrated ovano FIG. 5B, one or more components of the single pass mill 500 assembly can be flexible enough to allow the ring mill 542 to move outward.

In the embodiment of FIG. 5C, an annular mill 542 and an offset column 570 are illustrated after completion of the first operation mode. A displaceable string 570 is illustrated, which is further moved in the sleeve 555 downstream of the wellbore. Further movement of the displaceable string 570 may cause the annular milling machine 542 to move down the borehole along the milling channel 544 until the guide 546 reaches the end of the milling channel 544. The milling channel 544 may include a second inclined portion 548 to force the annular milling machine 542 to move to the side from formation 504 as it moves further along the milling channel 544. The second inclined portion 548 may be sufficiently high to cause the annular mill 542 to no longer touch the casing 524. So m, the height of the first inclined portion 547 and second taper portion 548 can be used to control the depth of the guide window 532, and the distance between the first inclined portion 547 and second taper portion 548 can be used to control the length of the guide box.

According to aspects of the present invention, an embodiment of the invention is a method comprising introducing a node into a first wellbore, the node comprising a deflecting tool; using the first mode of operation of the node to create a guide window in the casing of the first wellbore; securing the deflecting tool in the first wellbore; and using the second mode of operation of the node to start the second wellbore through the guide window.

In some embodiments of the invention, the second mode of operation may further include the rotation of the drill pipe string connected to the assembly. In some embodiments of the invention, the first mode of operation may further include fluid flowing through said drill pipe string and within said assembly. In some embodiments of the invention, the first mode of operation further includes the conversion of hydraulic energy from the fluid into a rotational force.

In any of the embodiments described in the previous two paragraphs, the method may further include disconnecting the drill pipe string from the deflecting tool. In some embodiments of the invention, a reclining deflecting wedge may serve as a deflecting tool. In any of the embodiments described in the previous two paragraphs, the method may further include changing the position of the deflecting tool in the first wellbore between the use of the first mode of operation and the use of the second mode of operation.

In accordance with aspects of the present invention, an embodiment of the invention is a system comprising an axial milling cutter coupled to an annular milling cutter, the system functioning: (1) in a first mode of operation, wherein the annular milling cutter creates a guide window in a casing of a first wellbore; and (2) in a second mode of operation in which an axial milling cutter starts a second wellbore through a guide window.

In some embodiments of the invention, the second mode of operation may further include the rotation of the drill pipe string connected to the axial milling cutter. In some embodiments of the invention, the first mode of operation may further include rotating the ring mill using a differential pressure. In some embodiments of the invention, the first mode of operation may further include creating a differential pressure, forcing the fluid to flow through the drill pipe string connected to the annular milling cutter. In some embodiments of the invention, the first mode of operation may further include converting the hydraulic energy of the fluid into a rotational force.

An embodiment of the invention is a system comprising a drill pipe string connected to an axial mill, a retractable deflecting wedge connected to the drill pipe string; a rotating column located inside the retractable deflecting wedge, and an annular milling cutter connected to the rotating column.

In some embodiments of the invention, the rotating column may further comprise a power section. In some embodiments of the invention, the rotating column may further comprise a mixer. In some embodiments of the invention, the rotating column may couple to a displaceable column. In some embodiments of the invention, one or more hydraulic seals may be located in the annular space between the displaced column and the retractable deflecting wedge.

In any of the embodiments of the invention in the two preceding paragraphs, the rotating column may further comprise a float valve. In any of the embodiments of the invention in the two preceding paragraphs, the annular milling cutter can be connected to the rotating column by means of a transmission. In any of the embodiments of the invention in the two preceding paragraphs, the annular milling cutter can be connected to the transmission via a bearing block.

Thus, this invention is well suited to achieve these, as well as its inherent objectives and advantages. The specific embodiments of the invention described above are only illustrative, since the invention can be modified and implemented in various, but equivalent ways, obvious to a person skilled in the art thanks to the ideas set forth herein. Furthermore, no limitation is provided for the structural details or diagrams illustrated herein, other than those disclosed in the claims below. Therefore, it is obvious that the specific illustrative embodiments of the invention described above can be changed or modified, and it is believed that all such variations are within the scope and essence of this invention. In addition, the terms in the claims have their simple, ordinary meaning, unless otherwise expressly and clearly defined by the patent holder. The use of the singular in the claims may mean one or more of the elements herein. In addition, the terms “connect” or “connects” or any common variant used in the detailed description or claims do not mean only direct connection. On the contrary, the two elements can be connected indirectly, but still be considered within the scope of the detailed description and claims as connected.

Claims (31)

1. A method of milling a guide window in a casing string, comprising the steps of: a milling assembly is inserted inside the first wellbore, said assembly comprising a deflecting tool; using the first mode of operation of the specified milling unit to create a guide window in the casing of the specified first wellbore; fixing said deflecting tool in said first wellbore; and use the second mode of operation of the specified milling unit to start the second wellbore through the specified guide window. 2. The method of claim 1, wherein said second mode of operation is used, further comprising rotating a drill string connected to said milling assembly. 3. The method of claim 2, wherein said first mode of operation is used, further comprising fluid flowing through said drill pipe string and into said milling assembly. 4. The method of claim 3, wherein said first mode of operation is used, further comprising converting hydraulic energy from said fluid to a rotational force. 5. The method according to PP. 1, 2, 3 or 4, further comprising the step of disconnecting said drill pipe string from said deflecting tool. 6. The method according to p. 5, characterized in that said deflecting tool is a removable deflecting wedge. 7. The method according to PP. 1, 2, 3 or 4, further comprising the step of changing the position of said deflecting tool in the first wellbore in the interval between using said first operating mode and using said second operating mode. 8. A system for milling a guide window in a casing string, comprising: an axial milling cutter connected to an annular milling cutter, said system being configured to function: (1) in a first mode of operation, wherein said annular milling cutter creates a guide window in a casing of a first wellbore; and (2) in a second mode of operation, wherein said axial milling cutter starts a second wellbore through said guide window. 9. The system of claim 8, wherein said second mode of operation includes rotation of a drill pipe string connected to an axial milling cutter. 10. The system of claim 9, wherein said first mode of operation further includes rotating said ring mill using a pressure differential. 11. The system of claim 10, wherein said first mode of operation further includes generating said pressure drop by forcing fluid to flow through a drill pipe string connected to said annular milling cutter. 12. The system of claim 11, wherein said first mode of operation further includes converting the hydraulic energy of said fluid into a rotational force. 13. The milling system of the guide window in the casing, containing: drill pipe string attached to an axial mill; a removable deflecting wedge attached to said drill pipe string; a rotating column located inside said recoverable deflecting wedge; and An annular milling cutter attached to said rotating column. 14. The system of claim 13, wherein said rotating column further comprises a power section. 15. The system of claim 14, wherein said rotating column further comprises a stirrer. 16. The system of claim 15, wherein said rotating column is connected to a displaceable column. 17. The system according to p. 16, characterized in that one or more hydraulic seals are located in the annular space between the specified offset column and the specified retractable deflecting wedge. 18. The system of claims. 13, 14, 15, 16 or 17, wherein said rotating column further comprises a float valve. 19. The system of claims. 13, 14, 15, 16 or 17, characterized in that said annular milling cutter is connected to said rotating column by means of a transmission. 20. The system of claims. 13, 14, 15, 16 or 17, characterized in that said ring milling cutter is connected to said transmission by means of a bearing block.

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