Patent Application
20210123312
Embodiments of the subject matter disclosed herein generally relate to downhole tools for well operations, and more specifically, to a wellbore setting tool that sets a plug at a desired depth into the well and then releases, at a desired time, a restriction element to close the plug.
During well exploration, various tools are lowered into the well and placed at desired positions for plugging, perforating, drilling, or measuring the well. These tools are placed inside the well with the help of a conduit, as a wireline, electric line, continuous coiled tubing, threaded work string, etc. Plugs are used to separate various sections of the well for perforating and/or fracturing purposes. The plugs block the casing so that a fluid from cannot pass the plug. The plugs need to be engineered to withstand a high pressure (thousands of psi) that is traditionally applied to the well, but also to be easily milled away after they have performed their duty.
A traditional plugging system 100 is shown in
The typical process of connecting the casing 114 to the subterranean formation 118 may include the following steps: (1) setting the plug 120, which has a through passage 122 inside the well, (2) closing the passage 122 to block fluid flow through the plug, (3) increasing the pressure inside the casing, and (4) perforating the casing 114 with a perforating gun 126. A controller 130, located at the surface 112, is used to control the various tools and/or the fluid's pressure inside the wellbore 116. In one application, a wireline tool 124 may be used to lower the setting tool 102, the plug 120, and the gun string 126.
The structure of the traditional setting tool 102 and plug 120 is illustrated in
To close the plug for preparing the well for perforating and/or fracturing, the setting tool 102 needs to be taken out of the well, a ball is introduced into the well and pumped down until the ball sits into a seat 218 located at a proximal end of the plug 120. The ball (not shown) closes the passage and the fluid pressure inside the well and above the plug 120 can be increased. However, the operation of taking the setting tool outside the well and then pumping down the ball is time consuming and expensive. Further, the existing plugs, although made from composite materials, still require a substantial amount of time to be milled out, when the need appears to remove them.
A more efficient plug is illustrated in
Sleeve 206 is configured to have a trap 302 for trapping the ball 310 when the well is flown back, as shown in
Returning to
The next string of guns, setting tool, ball, and plug is then lowered into the well for performing further perf and fracturing operations. The reason it is possible to lower the next gun string into the well is because the fluid that is pumped into the well exits the newly created perforations. The sequence repeats, and each of these sequences are called a stage. There could be many stages per well (e.g., >40). After all of the stages are done, the balls either dissolve, or a Coiled Tubing Run is used to mill them out and remove debris from the well.
If not enough of the perforations are created in any of the stages, it is called a mis-fire. The next string of guns or anything else cannot now be pumped down to its depth because the ball is preventing the fluid from being pumped into the well. Thus, the ball needs to be removed before the next string of guns can be pumped in. If a mis-fire happens, the well pressure at the surface is dropped quickly. This causes the fluid to flow-back out of the well. This means that the fluid in the well flows in an upstream direction, which makes the ball 310 to enter the sleeve 206 and become trapped by the trap 302. Now the guns, setting tool and the ball are removed from the well and the next gun string is pumped in as the removal of the ball 310 from the plug 120 allows the fluid to be pumped into the well.
The problem with this design is that if the ball is not caught, or if it is dropped when the tool is being removed, the well remains plugged. Then, a coiled tubing run is required to get to the plug and mill-out or capture the ball. After this blockage is removed, the perforating can continue. However, the coiled tubing run is slow and costly. Other existing approaches, as the ball in place or the drop ball methods, suffer from similar problems, and/or are more time consuming, and/or uses a large amount of water. Thus, there is a need for a setting tool and ball that have a simplified structure, are easy to be installed, and the ball can be released only when decided by the operator of the well.
According to an embodiment, there is a setting tool for setting a plug in a well. The setting tool includes a housing extending along a longitudinal axis X and having a bore, a sleeve extending along the longitudinal axis of the housing, and located within the bore of the housing, and a holding mechanism located within the sleeve and configured to hold a ball within the sleeve. The holding mechanism is configured to release the ball upon receiving a signal.
According to another embodiment, there is a setting tool for setting a plug in a well, the setting tool including a sleeve extending along a longitudinal axis and configured to be attached to the plug; a ball that fits inside a bore of the sleeve; and a holding mechanism located within the sleeve and configured to hold the ball within the sleeve. The holding mechanism is configured to release the ball upon receiving a signal.
According to yet another embodiment, there is a method for releasing a ball from a setting tool in a well, the method including loading the ball into the setting tool, securing the ball to the setting tool with a holding mechanism located within the setting tool, lowering the setting tool and the ball into the well, activating the setting tool to set up a plug inside the well, and releasing the ball into the well based on a signal received by the holding mechanism.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate one or more embodiments and, together with the description, explain these embodiments. In the drawings:
The following description of the embodiments refers to the accompanying drawings. The same reference numbers in different drawings identify the same or similar elements. The following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims. The following embodiments are discussed, for simplicity, with regard to a setting tool for releasing a restriction element to block a plug. However, the embodiments discussed herein are also applicable to other tools that need to release a restriction element at a desired instant in time.
Reference throughout the specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with an embodiment is included in at least one embodiment of the subject matter disclosed. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places throughout the specification is not necessarily referring to the same embodiment. Further, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.
According to an embodiment, there is a setting tool that holds a restriction element (e.g., a ball herein) and a plug that accepts the ball. The setting tool is attached to the plug. The setting tool sets the plug and then, it releases the ball to close the plug at a time that is decided by the operator of the plug. If a decision is made that the guns have failed to perforate or that the ball should not be released, the setting tool may be retrieved from the well while the ball is still locked inside the setting tool. Thus, according to this embodiment, there is no need to drill the ball or remove it by other means that are time and/or water consuming. The ball is simply not released into the well although the plug has been set. The ball is held inside the setting tool with a holding mechanism. The holding mechanism may be implemented, as discussed next, as a mechanical device, an electronic device, or as a flexo-mechanical device.
A setting tool-plug system 400 that includes a novel setting tool 410 is now discussed with regard to
The setting tool 410 includes a housing 420 and a sleeve 422 located within a bore 421 of the housing 420. The housing 420 is configured to contact the plug 480 while the sleeve 422 is attached to the inner mandrel 484 of the plug, with the shearing pins 486. When the setting tool is actuated, the housing 420 generates a reactionary force along the longitudinal axis X while the sleeve 422 is pulling the mandrel 484 along the opposite direction of the axis X, thus exerting a pulling force opposite to the reactionary force. In this way, the mandrel 484 is biasing the sealing element 482 toward a member 486, which results in the sealing element expanding along a radial direction and eventually touching the casing 470, as illustrated in
Returning to
The swinging arm 434 has a through hole 440 through which a pushing arm 442 extends, from one side of the swinging arm to the other. The pushing arm 442 has a shoulder 444, located between the swinging arm 434 and an upstream end 410A of the setting tool 410. A downstream end 410B of the setting tool is connected to the plug 480. Note that the terms “upstream” and “downstream” in this application refer to the head and toe of the well, respectively. Shoulder 444 is configured to pass through the hole 440 of the swinging arm 434 when the pushing arm 442 is free to move along the positive direction of the longitudinal axis X. However, as long as the plug 480 is attached to the setting tool as shown in
After the plug 480 has been set as illustrated in
At this time, the setting tool is armed for ball release. After enough perforations are made into the casing, the operator may decide to release the ball. To achieve this, the pump at the surface is used to pump the guns and the setting tool down onto the plug 480, so that the pushing arm 442 contacts the plug 480. The pushing arm 442 then starts to move along the negative direction of the longitudinal axis X, and shoulder 444 engages the swinging arm 434, which results in the swinging arm 434 being rotated about the fixed point 436, backward, i.e., in the upstream direction, as illustrated in
As previously discussed, the holding mechanism 430 that holds and controls the release of the ball 432 can be implemented as an electronic device, as now discussed with regard to
More specifically, the holding mechanism 430 in
A cross-section A-A trough the setting tool 810 is shown in
The motor 840 may be actuated in various ways for freeing the ball 432. For example, it is possible to have a cable 844 (see
In another embodiment, as illustrated in
In one implementation, the sensor 1120 may be implemented as an acoustic sensor. After a shaped charge of a gun is fired, the noise would be detected by the acoustic sensor. The signal generated by the acoustic sensor is transmitted to the controller, which compares an intensity of the signal to a given threshold. The firing of a shaped charge generates an intense signal. The presence of the intense signal confirms that perforations were made. Thus, the controller 1100 activates the motor 840 to release the ball 432.
In another implementation, it is possible to have a system 1200, as shown in
In still another embodiment, a shaped charge 1212 associated with the gun string 1210 creates a pressure pulse when fired. This pressure pulse can be used as the signal for instructing the controller 1100 to activate the motor 840. In this case, the sensor 1120 is a pressure sensor that is located outside the inner cavity 810.
In yet another embodiment, the sensor 1120 is an accelerometer. When the gun string 1210 fires, the gun string and also the setting tool 410, which is fixedly connected to the gun string 1210, experience a sudden movement (a jump). The accelerometer 1120 detects this jump and a signal indicative of it is sent to the controller 1100. The controller 1100 stores in a memory a threshold value and compares the jump experienced by the accelerometer with the threshold value. If the jump value is larger than the threshold value, the controller determines that the gun string has fired and motor 840 is activated to release the ball 432. Alternatively, the operator at the surface may raise or lower the setting tool 410, which is connected to a wireline 1240 or equivalent device, according to a known pattern. When the controller identifies the pattern based on the signals measured by the accelerometer 1120, the controller instructs the motor 840 to rotate to release the ball 432. In still another embodiment, the gun string and setting tool may be moved with a certain velocity pattern and the sensor 1120 may be selected to measure this velocity. When the measured pattern is identical to a stored velocity pattern, based on the signals measured by the accelerometer 1120, the controller instructs the motor 840 to rotate to release the ball 432. Other changes in well parameters may be used for communicating with the local controller 1120.
In yet another embodiment, as illustrated in
The well fluid 472 is able to enter inside the sleeve 422, through ports 420A formed in the housing of the setting tool 410 and ports 422A formed in the sleeve and move along paths 1330, from outside the setting tool to its inside. In addition, the ports are made into the housing 420 and the sleeve 422 so that the paths 1330 take the well fluid behind the ball 432, to push the ball outside the setting tool. In addition, the ports 420A and 422A are located in their corresponding housing and sleeve so that the ports are aligned with each other only when the setting tool has been separated from the plug, i.e., when the sleeve 422 has been retrieved inside the housing 420.
With this configuration, after the gun string's shaped charges have been fired, the operator moves the setting tool with a high velocity (which depends on the viscosity of the well fluid, diameter of the ports in the housing and sleeve, size of the ball, etc.) so that the well fluid 472 acts with a force against the ball and also makes the flexible walls 1312 of the mechanical enclosure 1310 to vibrate as indicated by arrows 1340, which eventually results in the mechanical enclosure flexing radially outward and the distance between the shoulders 1316 becoming larger than the diameter of the ball, so that the ball is released from the mechanical enclosure 1310 and ultimately from the setting tool 410. In one application, if the walls of the mechanical enclosure are made to be very flexible, the vibrations generated by the firing of the shaped charges of the gun string may force the ball out of the mechanical enclosure.
A method for operating a setting tool based on one or more of the embodiments discussed above is now discussed with regard to
The above-discussed global and local controllers may be implemented as a computing device as illustrated in
Server 1501 may also include one or more data storage devices, including hard drives 1512, CD-ROM drives 1514 and other hardware capable of reading and/or storing information, such as DVD, etc. In one embodiment, software for carrying out the above-discussed steps may be stored and distributed on a CD-ROM or DVD 1516, a USB storage device 1518 or other form of media capable of portably storing information. These storage media may be inserted into, and read by, devices such as CD-ROM drive 1514, disk drive 1512, etc. Server 1501 may be coupled to a display 1520, which may be any type of known display or presentation screen, such as LCD, plasma display, cathode ray tube (CRT), etc. A user input interface 1522 is provided, including one or more user interface mechanisms such as a mouse, keyboard, microphone, touchpad, touch screen, voice-recognition system, etc. The server may be part of a larger network configuration as in a global area network (GAN) such as the Internet 1528, which allows ultimate connection to various landline and/or mobile computing devices.
The disclosed embodiments provide methods and systems for setting a plug in a well and/or releasing a ball to close the plug. It should be understood that this description is not intended to limit the invention. On the contrary, the exemplary embodiments are intended to cover alternatives, modifications and equivalents, which are included in the spirit and scope of the invention as defined by the appended claims. Further, in the detailed description of the exemplary embodiments, numerous specific details are set forth in order to provide a comprehensive understanding of the claimed invention. However, one skilled in the art would understand that various embodiments may be practiced without such specific details.
Although the features and elements of the present exemplary embodiments are described in the embodiments in particular combinations, each feature or element can be used alone without the other features and elements of the embodiments or in various combinations with or without other features and elements disclosed herein.
This written description uses examples of the subject matter disclosed to enable any person skilled in the art to practice the same, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the subject matter is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2018/062754 | 11/28/2018 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62694068 | Jul 2018 | US |
