Certains contenus de cette application ne sont pas disponibles pour le moment.
Si cette situation persiste, veuillez nous contacter àObservations et contact
1. (WO2019067402) FORAGE AVEC UN SYSTÈME DE SIFFLET DÉVIATEUR
Note: Texte fondé sur des processus automatiques de reconnaissance optique de caractères. Seule la version PDF a une valeur juridique

Drilling with a Whipstock System

CLAIM OF PRIORITY

This application claims priority to U. S. Patent Application No. 15/718,942 filed on September 28, 2017, the entire contents of which are hereby incorporated by reference.

TECHNICAL FIELD

This invention relates to a whipstock system, for example, to perform a whipstock installation within a wellbore.

BACKGROUND

Wellbores can be drilled into geologic formations for a variety of reasons, such as, for example, hydrocarbon production, fluid injection, or water production. In the oil and gas industry, a whipstock can be used for sidetracking an initial wellbore or in preparation for directional or horizontal drilling. This process is carried out, for example, to direct a drill string into a new formation, to avoid abandoned objects downhole, or to perform a casing milling operation to cut into the casing around an existing wellbore.

SUMMARY

This disclosure describes tools and methods relating to drilling with whipstock tools that include an independent hydraulic system controlled wirelessly from the surface and/or from a measurement while drilling (MWD) sub assembly. The whipstock tool has independent hydraulic power units that can activate and de-activate tool components such as, for example, upper slips, fluid-isolating rubber elements, and lower slips multiple times. Transmitters and receivers are located at a control unit part of the whipstock tool. In some applications, these transmitters and receivers provide real-time communication between the whipstock tool and the surface, delivering, for example, information regarding the functioning of the whipstock to the surface and commands to the whipstock tool.

Use of an independent hydraulic system controlled wirelessly from the surface or from a MWD sub eliminates the need for a hydraulic control line from the milling assembly to the whipstock tool. This approach increases the robustness of the

l

whipstock system by eliminating the possibility of failure due to damage to the control line while running in hole. The whipstock assembly allows drilling and completion engineers to monitor the functionality of the system and evaluate the mechanisms in real time, identifying premature failures and reducing the costs of the operation.

A whipstock system includes a whipstock body, a control unit mounted on or in the whipstock body, the control unit comprising transmitters and receivers operable to receive commands from an external source, activatable components mounted on or in the whipstock body, and a hydraulic system in the whipstock body, the hydraulic system in communication with the control unit, the hydraulic system including at last one hydraulic power unit operable to repeatedly activate and de-activate the activatable components.

In some implementations, the activatable components include at least one slips assembly and at least one seal assembly. The activatable components include an upper slips assembly and a lower slips assembly. The hydraulic system includes a reservoir and an expansion chamber in the whipstock body, and a pump in the whipstock body in fluid communication with the reservoir and the expansion chamber, wherein transfer of fluid from the reservoir to the expansion chamber activates at least one of the activatable components. The control unit includes one or more processors, and a computer-readable medium storing instructions executable by the one or more processors to perform operations comprising receiving, from the external source, instructions to perform whipstock operations within the wellbore, and transmitting, to the hydraulic system, at least a portion of the instructions. The hydraulic power unit is operatively coupled to the one or more processors and the hydraulic power unit configured to receive at least the portion of the instructions from the one or more processors. The pump is hydraulically connected to an upper slips assembly or a lower slips assembly.

In some implementations, the whipstock system has a mandrel movable to engage an anchor portion of the upper slips assembly or lower slips assembly. The hydraulic pump is hydraulically connected to the at least one seal assembly. The operations further include receiving, from the whipstock assembly, status signals representing a whipstock status of the at least one of the plurality of whipstock assembly, and transmitting, to the surface of the wellbore, the status signals. The external source includes one or more transmitters at the surface, the one or more

transmitters configured to transmit the instructions to the one or more processors, and one or more receivers at the surface, the one or more receivers configured to receive the status signals from the one or more processors. The one or more transmitters and the one or more receivers are configured to communicate wirelessly with the one or more processors. The control assembly further includes a power source mounted on or in the whipstock body, the power source electrically coupled to the one or more processors. The power source is a wireless, stand-alone power source. The wireless, stand-alone power source is a lithium battery. The hydraulic system includes a check valve.

In some aspects a method of deploying a whipstock in a wellbore includes receiving, by a control assembly deployed within a wellbore, instructions to perform whipstock operations within the wellbore, transmitting, by the control unit, at least a portion of the instructions to a hydraulic system on a whipstock assembly, and activating at least one independent hydraulic power unit of the hydraulic system in response to the portion of the instructions transmitted by the control unit to activate components of the whipstock assembly. Activing at least one independent hydraulic power unit of the hydraulic system to activate components of the whipstock assembly includes activating at least one independent hydraulic power unit of the hydraulic system to activate a slips assembly or a seal assembly of the whipstock assembly. Activating at least one independent hydraulic power unit of the hydraulic system in response to the portion of the instructions transmitted by the control unit to deactivate components of the whipstock assembly. Activating at least one independent hydraulic power unit of the hydraulic system includes pumping fluid from a reservoir in the whipstock assembly to an expansion chamber of the whipstock assembly.

The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram of a wellbore drilling system.

FIG. 2 is a side view of a whipstock assembly for use in a wellbore drilling system.

FIG. 3 shows a block diagram of an example control system of the whipstock assembly of FIG. 2.

FIG. 4A is a schematic side view of a portion of an example whipstock assembly with anchors or slips deactivated.

FIG. 4B is a schematic side view of a portion of the example whipstock assembly with anchors or slips activated.

FIG. 5A is a schematic side view of a portion of an example whipstock assembly with rubber seals deactivated.

FIG. 5B is a schematic side view of a portion of an example whipstock assembly with rubber seals activated.

FIG. 6 is a flowchart showing an example method of controlling a whipstock tool.

Like reference numbers and designations in the various drawings indicate like elements.

DETAILED DESCRIPTION

This disclosure describes tools and methods relating to drilling with whipstock tools that include an independent hydraulic system controlled wirelessly from the surface and/or from a MWD sub assembly. The whipstock tool has independent hydraulic power units that can activate and de-activate tool components such as, for example, upper slips, fluid-isolating rubber elements, and lower slips multiple times. Transmitters and receivers are located at a control unit part of the whipstock tool. In some applications, these transmitters and receivers provide real-time communication between the whipstock tool and the surface delivering, for example, information regarding the functioning of the whipstock to the surface and commands to the whipstock tool.

Use of an independent hydraulic system controlled wirelessly from the surface or from a MWD sub eliminates the need for a hydraulic control line from the milling assembly to the whipstock tool. This approach increases the robustness of the whipstock system by eliminating the possibility of failure due to damage to the control line while running in hole. The whipstock assembly allows drilling and completion engineers to monitor the functionality of the system and evaluate the mechanisms in real time, identifying premature failures and reducing the costs of the operation.

FIG. 1 shows an example wellbore drilling system 100 being used in a wellbore 106. The well drilling system 100 includes a drill derrick 1 15 that supports the weight of and selectively positions a drill string 108 in the wellbore 106. The drill string 108 has a downhole end connected to a mill 1 10 that is used to extend the wellbore 106 in the formation 104. Once drilled, the wellbore 106 is provided with a casing 1 18 that provides additional strength and support to the wellbore 106. The wellbore drilling system 100 can include a bottom hole assembly (BHA) 102. The BHA 102 includes a MWD sub 120. The BHA 102 also includes a control assembly

101 mounted on and carried by the BHA 102. The control assembly 101 is designed to be deployed in the wellbore 106 and is configured to handle shock-loads, corrosive chemicals, or other potential downhole hazards.

To sidetrack from the wellbore 106, the drill string 108 and BHA 102 are withdrawn from the wellbore 106. A whipstock 200 is deployed into the wellbore 106 and prepared for operation as is described in more detail with respect to FIGS. 2-6. The drill string 108 and BHA 102 are deployed back down the wellbore 106 to the position of the whipstock 200. Contact with the whipstock 200 deflects the milling or boring direction of the mill 1 10 from its orientation in the previously drilled wellbore 106 toward a selected different direction.

The wellbore drilling system 100 includes one or more transmitters 1 12 at the surface 116. The one or more transmitters 112 can transmit whipstock operation instructions to the control assembly 101 or directly to the whipstock 200. In addition to the transmitters 1 12, one or more receivers 1 13 are positioned at the surface 1 16. The one or more receivers 113 are operable to receive one or more status signals from the control assembly 101. Each of the one or more transmitters 1 12 and the one or more receivers 1 13 communicate (for example, wirelessly) with the control assembly 101. In some implementations, the wireless communication include radio frequency communication, such as Wi-Fi. In some implementations, the wellbore drilling system 100 includes control wires providing communications with the control assembly 101 and the control assembly 101 includes a transmitter operable to communicate with the whipstock tool 200. In some implementations, the wellbore drilling system 100 includes one or more repeaters 1 14 positioned between the surface 1 16 and the BHA

102 within the wellbore 106. The repeaters 1 14 can boost a strength of a wireless

signal between the one or more transmitters 112 or the one or more receivers 113 and the control assembly 101.

The wellbore drilling system 100 can be used in forming vertical, deviated, and horizontal wellbores. In some implementations, the wellbore drilling system 100 includes a sub 103 operable to receive status signals of the BHA 102 and transmit instructions to the BHA 102. In such an implementation, data received from the BHA 102 can be stored in the sub 103 and can be retrieved after the sub is returned to the topside facility.

FIG. 2 shows a whipstock tool 200 that includes a whipstock ramp 202 positioned upward from a whipstock sub body 204. The whipstock tool 200 includes independent hydraulic power units 310, 312, 314 (depicted in FIG. 3) that can activate and de-activate tool components such as, for example, upper slips 206, seals 210, and lower slips 208 multiple times. Some whipstock tools include additional or altemative deployable components. The whipstock tool 200 also includes a control unit 220 and a battery 222. The control unit 220 includes one or more transmitters and receivers. In some applications, these transmitters and receivers provide real-time communication between the whipstock tool and the surface delivering, for example, information regarding the functioning of the whipstock to the surface and commands to the whipstock tool.

The whipstock tool 200 can be used in a method of providing directional drilling from a wellbore 106 that has been already drilled and, in some instances, cased. The whipstock ramp 202 includes a tapered steel guide for the drill string whose function is to deflect the milling or boring direction of the mill 110 from its orientation in a previously drilled wellbore, toward a selected different direction. The guide taper or ramp 202 provides a whipstock deflection surface that turns the borehole axis from alignment with the existing borehole to a deflected orientation (for example, the deflected orientation can be about 1° to about 10° relative to the axis of the main wellbore).

The whipstock sub body 204 is secured within an existing borehole casing 118 or wellbore 106 by slips or anchors 206, 208 located along the whipstock length below the bottom end of the deflection surface. The slips 206, 208 are firmly anchored to oppose the forces on the whipstock tool 200 along the existing borehole axis and the torque force imposed by the deflected drill string rotation.

The seals 210 engage sides of the existing borehole 106 below the whipstock sub body 204 and limit fluid communication between the lower portion of the existing wellbore and the new, deflected borehole.

The whipstock tool 200 deflects the bit cutting direction within the casing, which turns the mill 1 10 into the wall of the casing 118. After the whipstock sub body 204 is set, a window is milled into the wall of the casing 118 to provide a guide for the mill 1 10 to cut into the earth along the new, deflected direction. The window is milled by a steel milling tool with a milling bit at the end of the drill string 108. In some instances, one or more hole reaming tools can follow to enlarge the casing window.

The MWD sub 120 (see FIG. 1) reports downhole characteristics of the drilling operation (for example, location and orientation of the downhole components) to a surface receiver 1 13. When the face of the whipstock deflection surface ramp 202 is directionally oriented, the slips 206, 208 are engaged by fluid pressure.

Use of an independent hydraulic system controlled wirelessly from the surface or from a MWD sub eliminates the need for a hydraulic control line from the milling assembly to the whipstock tool. This approach increases the robustness of the whipstock system by eliminating the possibility of failure due to damage to the control line while running in hole and removing the need tubing and valves associated with the control line that are vulnerable to malfunction and in-running damage. In addition, the whipstock assembly allows drilling and completion engineers to monitor the functionality of the system and evaluate the mechanisms in real time, identifying premature failures and reducing the costs of the operation.

FIG. 3 shows a block diagram of a control assembly 220 for controlling the whipstock tool 200. The control assembly 220 includes one or more processors 306 and a computer-readable medium 318 storing instructions executable by the one or more processors 306 to perform operations. The control assembly 220 also includes a transmitter 302 and receiver 304 that can be used to receive, from the surface 1 16, instructions to perform whipstock operations within the wellbore, and transmit at least a portion of the instructions to components such as, for example, the upper slips 206, lower slips 208, and/or rubber seals 210 of the whipstock tool 200. The receiver 304 also receives status signals representing a status of the whipstock tool 200. The transmitter 302 can also transmit the status signals to the surface 1 16. The status signals can include a state of a whipstock assembly (such as an "on" state or an "off state), a hydraulic pressure of hydraulic power units of the whipstock tool 200, or the status of other components of the assembly. In some implementations, each of the upper slips 206, lower slips 208, and rubber seals 210 can communicate with the control tool, for example, through a control wires, wirelessly, or hydraulically.

The whipstock 200 includes the control unit 220 as a component of the whipstock. In some systems, the control unit is part of the BHA 102.

Control assemblies include a power source 308 is operatively coupled to the one or more processors 306 and can provide operating power to the one or more processors 306. In the whipstock 200, the power source 308 is the battery 222 (for example, a lithium ion battery).

The whipstock tool 200 includes at least one hydraulic power unit. For example, the whipstock 200 of the wellbore drilling system 100 includes as a first hydraulic power unit 310, a second hydraulic power unit 312, and a third hydraulic power unit 314, operatively coupled to the one or more processors 306 of the control unit 220. The hydraulic power units can receive at least a portion of a set of instructions from the one or more processors 306. The hydraulic power units may receive instructions to change states ("on" command or "off command) of the hydraulic pump, set a target pressure for the hydraulic pump, or any other command that can be executed by the hydraulic power unit. In some implementations, the different hydraulic power units are interconnected to allow fluidic communication between each hydraulic power unit. The interconnection can allow a hydraulic power unit to control multiple whipstock subparts such as the upper slips 206, lower slips 208, and rubber seals 210 in the event of the failure of a hydraulic power unit. In some implementations, each of the whipstock tools include a separate control tool to facilitate communications with the control assembly 220. The one or more processors 306 are coupled to an electrical power source 316 that sends electrical power to the whipstock tool 200.

FIGS. 4A-4B show a portion of an example whipstock tool 400 in various stages of operation. In FIG. 4A, slips 408 of the whipstock tool 400 are in a deactivated mode, while in FIG. 4B, the slips 408 of the whipstock tool 400 are in an activated mode. The slip assembly 400 includes a hydraulic power unit 401 operatively coupled to the control assembly 220 (for example, the first hydraulic power unit 310 or third hydraulic power unit 314 described with respect to FIG. 3).

The hydraulic power unit 401 can act as the activation and deactivation unit for the upper slips 206 or lower slips 208.

The hydraulic power unit 401 can receive instructions from the control assembly 220. The instructions can include, for example, changing states of a hydraulic pump 404, changing an output pressure of the hydraulic pump 404, changing position of an actuatable tool such as the slips 408, or other commands that can be executed by the hydraulic power unit. The slips 408 are operatively coupled to the hydraulic power unit 401 such that the hydraulic power unit 401 can mechanically activate the tool to begin an anchoring operation within the wellbore 106 responsive to being activated. The anchors 408 can correspond to either of the upper slips 206 or lower slips 208.

The hydraulic power unit 401 includes a reservoir 402 and a hydraulic pump 404 fluidly connected to the reservoir 402 and the anchors 408. The hydraulic pump 404 can apply hydraulic fluid from reservoir 402, at a pressure sufficient to activate the slip assembly 400. Application of the hydraulic fluid to the slip assembly 400 causes the anchors 408 to extend radially outward from the slip assembly 400 and towards the wall of the wellbore 106. The slip assembly 400 includes sensors 410 to relay information back to the control assembly 220, such as hydraulic pressure or anchor 408 position.

Once the hydraulic power unit 401 has received a signal to activate the slip assembly 400, the hydraulic pump 404 moves hydraulic fluid from the hydraulic reservoir 402 to an expansion member 406. The expansion member 406 begins to expand. Expansion of the expansion member 406 moves a wedged mandrel 414 towards the anchors 408. The wedge shaped mandrel 414 causes the anchors 408 to extend radially outward from the slip assembly 400 and towards the wall of the wellbore 106.

The hydraulic pump 404 includes a check-valve 420 that prevents back-flow from the expansion member 406 to the hydraulic reservoir 402. In some

implementations, the hydraulic power unit 401 includes one or more pressure sensors to measure a pressure of the hydraulic fluid. The pressure value detected by the one or more pressure sensors can be sent to the controller assembly 101, and the controller assembly 101 then transmits the pressure value to the surface 116. Once whipstock operations are completed, the control assembly 220 sends a signal to the hydraulic

pump 404 to pump hydraulic fluid from the expansion member back into the hydraulic fluid reservoir. In some embodiments, the slip assembly 400 includes a retraction device, such as a spring 412, to return the mandrel 408 and anchors 408 back into the retracted position once the hydraulic fluid has been removed from the expansion member 406. The expansion member 406 can include, for example, a bladder, a piston, or any other expandable actuation device. In some implementations, the hydraulic power unit 401 may be fluidly connected to a separate hydraulic power unit in another portion of the whipstock assembly. Such a connection allows a single hydraulic power unit to control multiple components of the whipstock assembly in the event of a failure of one of the hydraulic power units.

FIGS. 5A-5B show a rubber seal assembly 510 of a whipstock tool 500 in various stages of operation. In FIG. 5 A, rubber elements 510a, 510b, 510c of seal 510 in the seal assembly 510 are in a deactivated mode, while in FIG. 5B, rubber elements 510a, 510b, 510c are in an activated mode. The whipstock tool 500 includes a hydraulic power unit 501 operatively coupled to the control assembly 220 (for example, the second hydraulic power unit 312 described with respect of FIG. 3) and that has a check valve 520. The hydraulic power unit 501 receives instructions from the control assembly 220. The whipstock instructions can include changing states of the hydraulic pump 504, changing an output pressure of the hydraulic pump 504, changing position of an actuatable tool such as rubber seal assembly 510 or other commands that can be executed by the hydraulic power unit. The tool is operatively coupled to the hydraulic power unit 501, that is, the hydraulic power unit 501 mechanically activates the rubber elements 510a, 510b, 510c to engage the casing 1 18 within the wellbore 106 to provide a fluid seal. For example, the hydraulic power unit 501 may cause the individual rubber elements 510a, 510b, 510c of seal assembly 510 to extend radially outward from the rubber element assembly 500 and towards the wall of the wellbore 106. In some implementations, the whipstock 500 includes sensors 512 to relay back information to the control assembly 220, such as hydraulic pressure or position of position of the rubber elements.

Once the hydraulic power unit 501 has received a signal to activate the seal assembly 510, the hydraulic pump 504 moves hydraulic fluid from a hydraulic reservoir 502 to an expansion member 506 to activate the seal assembly 510. The expansion member 506 moves a wedged mandrel 508 towards the rubber elements

510a, 510b, 510c. The wedge shaped mandrel 508 causes the rubber elements 510a, 510b, 510c to extend radially outward from the rubber element assembly 500 and towards the wall of the wellbore 106 or casing 1 18.

On deactivation, the hydraulic pump transfers hydraulic fluid from the expansion member 506 back into the hydraulic fluid reservoir. The rubber element assembly 500 can include a retraction device 522, such as a spring, to return the mandrel 508 and rubber elements 510 back into the retracted position once the hydraulic fluid has been removed from the expandable member 506. In some implementations, the hydraulic power unit 501 may be fiuidly connected to a separate hydraulic power unit in another portion of the whipstock tool 200. Such a connection allows for a single hydraulic power unit to control assemblies in the event of a failure of one of the hydraulic power units, such as hydraulic power unit 501.

FIG. 6 shows a flowchart of an example method 600 used for the wellbore drilling system 100. At 602, instructions to perform whipstock operations within the wellbore 106 are received from a surface 1 16 by a control assembly deployed within a wellbore 106. At 604, at least a portion of the whipstock instructions is transmitted by the control assembly to at least one component of the whipstock assembly, such as the slips 400 or the seal assembly 510. The control assembly 220 receives these instructions from the surface or the MWD sub via the receiver 304 installed in the control assembly 220. The one or more processors 306 of the control assembly 101 analyzes and identifies which HPU to be activate, HPU 310 or 314 for whipstock anchors or upper slips 206 or lower slips 208, respectively, or HPU 312 for the rubber seal assembly 210.

At 606, a respective whipstock component is activated by at least one of the HPUs 310, 312, 314 to anchor the tool within the wellbore 106. Each HPU 310, 312, 314 can be activated independently. Additionally, status signals representing a whipstock status of the at least one of the whipstock assemblies are transmitted by at least one of the whipstock assemblies to the control assembly 220. The status signals from the at least one of whipstock components is received by the control assembly 220. In some implementations the status signals from the at least one of the whipstock assemblies is transmitted to the surface 1 16 by the control assembly 220. The activated HPU(s) transfers hydraulic fluid from the respective reservoir(s) as described above.

At step 606, one of more of the whipstock components may be de-activated, rather than activated, by at least one of the HPUs 310, 312, 314 to release the tool or seal from within the wellbore 106. Each HPU 310, 312, 314 can be deactivated independently. Additionally, status signals representing a whipstock status of the at least one of the whipstock assemblies is transmitted by at least one of the whipstock assemblies to the control assembly 220. The status signals from the at least one of whipstock assemblies is received by the control assembly 220. In some

implementations the status signals from the at least one of the whipstock assemblies is transmitted to the surface 116 by the control assembly 220. The activated HPU(s) transfers hydraulic fluid back to the respective reservoir(s) as described above.

While this specification contains many specific implementation details, these should not be construed as limitations on the scope of any inventions or of what may be claimed, but rather as descriptions of features specific to particular implementations of particular inventions. Certain features that are described in this specification in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

Thus, particular implementations of the subject matter have been described. Other implementations are within the scope of the following claims. In some cases,

the actions recited in the claims can be performed in a different order and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In certain implementations, multitasking and parallel processing may be advantageous.

A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.