Embodiments of the subject matter disclosed herein generally relate to a tool that is lowered into a casing of a well and needs to be fixed at a certain position in the well, and more specifically, to a braking and setting mechanism that achieves this functionality in the well.
In the oil and gas field, once a well is drilled to a desired depth H relative to the surface, and the casing protecting the wellbore has been installed and cemented in place, it is time to connect the wellbore to the subterranean formation to extract the oil and/or gas. This process of connecting the wellbore to the subterranean formation may include a step of fluidly insulating with a plug a previously fractured stage of the well, a step of perforating a portion of the casing, which corresponds to a new stage, with a perforating gun such that various channels are formed to connect the subterranean formation to the inside of the casing, a step of removing the perforating gun, and a step of fracturing the various channels of the new stage by pumping a fluid into the channels. These steps are repeated until all the stages of the well are fractured.
During one or more of these steps, it is often the case that a perforating gun needs to be deployed in a certain stage, at a predetermined position in the well, and be fired so that the shaped charges of the perforating gun establish channels between the inside of the casing and the oil formation around the casing, thus achieving a fluid communication between the inside and outside of the casing. Positioning the perforating plug to the desired location in the well is typically achieved with a wireline or similar tool. Once the perforating gun has arrived in position, its shaped charges are fired to create perforations into the casing of the well. After one or all of the perforating guns are fired, they are pulled out of the well with the wireline.
However, more recent perforating guns are released into the well without a wireline or with a slickline, with the intent of not retrieving them from the well. For this case, most parts of the perforating gun may be dissolvable, which means that they can be left inside the well and they will eventually dissolve and disappear. For this kind of perforating guns, no wireline may be used to deploy then. These perforating guns are simply released inside the well and driven by pumping a fluid behind them until the guns arrive at the desired position in the well. As there is no wireline to stop the movement of the perforating guns inside the well, or the used slickline cannot withstand the tension generated by the moving perforating guns, a braking mechanism has been provided to each perforating gun and this braking mechanism is configured to be deployed to the desired location in the well where the perforating gun should be fired to fix the gun at that position.
The existing braking mechanisms use an ignitor (a detonating material) which is configured to ignite a power charge inside the perforating gun, and this power charge actuates one or more arms to extend from the body of the perforating gun toward the casing of the well, and eventually to push against the casing to stop the movement of the perforating gun. Note that the ignitor and the power charge are in addition to the existing shaped charges, detonator cords, and detonators and these elements act independent of each other.
One of the problems with such a braking mechanism is that from a regulatory standpoint, in a perforating gun, every explosive must be accounted for, and the mixing of different types of explosives (explosive for the shaped charges, cords and detonators, and explosive for the braking mechanism, which are typically made of different materials) can change the shipping class of the perforating gun to a more sensitive classification, which makes the assembly and shipping of the perforating gun from the manufacturer to the operator of the well more cumbersome.
Thus, there is a need to eliminate the explosive material associated with the braking mechanism to at least simplify the regulatory aspects, but also to make the entire device less prone to accidents.
According to an embodiment, there is a braking and setting device configured to slow down a movement of a tool in a well and to fix the tool relative to the well. The braking and setting device includes two or more arms configured to extend from the tool, toward the well, to brake the movement of the tool along a longitudinal axis X; a movable piston configured to be hosted fully within the tool and to move only when a well fluid acts on a base portion of the movable piston, while a tip portion of the movable piston pushes away the two or more arms; and an actuation mechanism configured to establish a fluid communication between the well fluid and the base portion of the movable piston. The movable piston moves exclusively due to a force exerted by the well fluid on the movable piston.
According to another embodiment, there is a perforating gun configured to slow down in a well and fix to a casing of the well. The perforating gun includes a body extending along a longitudinal axis X; one or more shaped charges configured to make a perforation in the well; a detonator cord connected to the one more shaped charges; and a braking and setting device partially located within the body and configured to slow down a movement of the body in the well and to fix the body relative to the well. The braking and setting device brakes and sets the body exclusively due to a force exerted by the well fluid.
According to still another embodiment, there is a method of deploying a perforating gun into a well with a braking and setting device. The method includes releasing the perforating gun into the well; sending a command to the perforating gun to actuate the braking and setting device; actuating an actuation mechanism, based on the received command, to open a fluid communication between a well fluid from the well and a movable piston of the braking and setting device; moving the movable piston exclusively due to a force exerted by the well fluid, where the movable piston pushes away two or more arms against a casing of the well to brake the perforating gun; and setting the perforating gun to be fixed relative to the casing with the two or more arms.
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 single perforating gun used for perforating a casing in a horizontal well. However, the embodiments discussed herein may be used for plural perforating guns or other tools that are used in a well, and also for tools that are provided inside a vertical well.
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, a perforating gun includes, in addition to the shaped charges, detonator, and detonation cord, a braking and setting mechanism that uses no ignitor and no power charge for braking and fixing the associated perforating gun to a desired position inside the well. The braking and setting mechanism is activated exclusively by a pressure of a fluid that is present in the well, i.e., the well pressure. The pressure of the fluid may be the hydrostatic pressure plus an applied pressure, which is applied by the operator of the well with a pump at the head of the well. An actuation mechanism, for example, a valve, is configured to open a passage that fluidly communicates the outside of the perforating gun with a wedge piston. The valve opens when a command is received and allows the well fluid to press on the wedge piston, to move the braking arms outside a body of the perforating gun, to contact the casing and stop the movement of the perforating gun. Details of these features are now discussed with regard to the figures.
When the perforating gun 110 arrives next to the oil formation 108, as illustrated in
The braking and setting mechanism 112 is shown in more detail in
The movable piston 310 may be made from a dissolvable metal or a composite material that can be easily drilled. The movable piston 310 also has a base portion 314B, and the base portion is shaped as a cylinder. The tip portion 314A has a smaller diameter than the base portion 314B. One or more o-rings 316 are placed around the movable piston 310 to seal an interface between the movable piston and a first internal chamber 318 located inside the body 111. The first internal chamber 318 fluidly communicates with a second internal chamber 330, also located inside the body 111. While the first internal chamber 318 hosts the movable piston 310, the second internal chamber 330 hosts an actuation mechanism 340. The first internal chamber 318 fluidly communicates with the second internal chamber 330 through a passage 332. The second internal chamber 330 also fluidly communicates with an ambient of the housing 302, i.e., with the well fluid 126, through a dedicated passage 334. The passage 334 is configured to not allow the well fluid 126 to enter in the annulus space 113, between the housing 302 and the body 111. While the well fluid 126 can freely enter from the casing 104, through the passage 334, into a first sub-chamber 330A of the second internal chamber 330, the well fluid 126 is prevented by the o-rings 316 from entering a second sub-chamber 330B. The second sub-chamber 330B is separated from the first sub-chamber 330A by a second movable piston 336. The second movable piston 336 includes a tip portion 336A and a base portion 336B. The tip portion 336A has a smaller diameter than the base portion 336B. The tip portion 336A is configured to exactly fit inside the passage 332 to prevent the well fluid 126 from entering from the first sub-chamber 330A into a second sub-chamber 318B of the first internal chamber 318. In this regard, note that the movable piston 310 and more precisely the base portion 314B of the movable piston 310 splits the first internal chamber 318 into a first sub-chamber 318A and the second sub-chamber 318B. Also note that the base portion 314B of the movable piston 310 fluidly insulates the first sub-chamber from the second sub-chamber due to the o-ring 316.
Returning to the actuation mechanism 340, it includes, in this embodiment, a fuse 342 which is configured to hold a spring 344 (compressional or torsional) tightly wound around a split nut 346 (see, for example, U.S. Patent Publication no. US2018/0347314, which is incorporated herein by reference and is assigned to the present assignee). The split nut 346 is preventing the moving piston 336 from shifting, and thus, from allowing the well fluid 126 to move into the passage 332. The split nut 346 is located on an extension 336C of the base portion 336B. Note that also because the diameter of the base portion 336B is larger than the diameter of the top portion 336A of the moving piston 336, the pressure exerted by the well fluid on the movable piston 336 is opposite to the positive direction of the longitudinal axis X of the perforating gun, thus, further preventing the second movable piston 330 from opening the passage 332.
The fuse 342 is connected to a signal wire 350, that exits through a port 352 from the housing 302 of the perforating gun 110. When an electrical signal is sent through the signal wire 350, the fuse 342 burns, and the spring 344 springs outwardly releasing the segments of the split nut 346, and thus allowing the moving piston 336 to move to the left in the figure, i.e., along the negative direction of the longitudinal axis X. When this happens, the tip portion 336A of the moving piston 336 exits the passage 332 and allows the well fluid 126 to enter from the passage 334 into the first chamber 318, to exert a pressure on the first movable piston 310.
While
When this happens, the well fluid 126 enters the second sub-chamber 318B of the first chamber 318 and applies a force directly on the movable piston 310. As the pressure inside the first sub-chamber 318A (atmospheric pressure) of the first chamber 318 is much smaller than the well fluid pressure inside the second sub-chamber 3186, and also because the force exerted by the well pressure on the tip portion 314A of the movable piston is smaller than the force exerted on the base portion 314B, the first movable piston 310 is forced to move to the right in the figure, in the positive direction of the longitudinal axis X, which results in pushing away the arms 114A and 1146 of the braking and setting mechanism 112. In this way, due exclusively to the pressure of the well fluid 126, the braking and setting mechanism is activated and the perforating gun 110 housing this mechanism is fixed in place inside the casing, at a desired location. Note that the well fluid pressure is either given by the hydrostatic pressure of the fluid inside the well, or by a combination of the hydrostatic pressure and an additional pressure applied by the pump from the head of the well. No matter which approach is taken, the actuation mechanism 340 needs to be electrically actuated in this embodiment at the desired location where the perforating gun needs to be fixed, and then the well fluid pressure actuates the arms of the braking mechanism. As previously discussed, the actuation mechanism 340 can be activated either due to a sensor 352, or through an electric line that extends from the head of the well to the port 352.
In one embodiment, as illustrated in
When the gun 110-1 arrives at the desired location in the casing, a command is sent through the wire 350 to the actuation mechanism 340, as discussed above. This command is sent from the controller 122, either along the slickline 354 as an electrical signal, if the slickline is present, or through the well fluid 126, as a pressure wave that is recorded by the sensor 352. The pressure wave may result in the pressure PH being modulated, for example, by the pump 120 at the surface. Alternatively, a sound modem may be used to transmit a sound through the well fluid to the sensor 352. Irrespective of how the actuation mechanism 340 is activated, once the well pressure enters inside the braking and setting mechanism 112, it forces the arms 114A and 114B to extend and fix the first perforating gun 110-1 to the casing, as shown in
If the perforating guns are attached to a slickline, then the shaped charges may be initiated by sending a command to their detonators along the slickline. However, for the case that the perforating guns are completely autonomous, i.e., no wireline, then a new configuration is necessary for activating the detonator to fire the corresponding shaped charges.
In this regard,
The connection device 500 is shown in
To actuate the moving pin 514, various approaches may be used. In this embodiment, for example, a dissolvable collar 518 may be attached to the part of the moving pin that extends into the channels 512. The collar 518 prevents the pin 514 from entering into the bore 510. When the perforating gun is in the well, the well fluid enters through the channels 512 and start dissolving the dissolvable collar 518. Because of the various o-rings 516, the bore 510 is at this time filled with air at atmospheric pressure and the well fluid cannot enter into the bore because the moving pin seals the bore. The moving pin does not move into the bore due to the large pressure difference because the dissolvable collar prevents this move. However, once enough of the dissolvable collar has been dissolved by the well fluid, the moving pin is freed from this hold, and the pressure difference between the well fluid and the air inside the bore 510 suddenly exerts a large force on the moving pin. Due to this force, the moving pin travels with a high speed inside the bore 510, to the right in the figure, and hits the detonator 366, thus activating it. Those skilled in the art would understand that this is only one possible configuration of the connection device 500 and other configurations may be implemented based on the teachings in this disclosure.
When the connection devices 500 are used to connect together the various perforating guns that are lowered together into the casing, and after a given perforating gun is fixed relative to the casing and the other perforating guns are moved further down the casing, then the fixed perforating gun 110-1 would look as shown in
A method for deploying a perforating gun into a well with the help of a braking and setting device is now discussed with regard to
The disclosed embodiments provide methods and mechanisms for braking the movement of a tool inside a well and fixing the tool relative to the well. 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.
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Number | Date | Country | |
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20210388687 A1 | Dec 2021 | US |
Number | Date | Country | |
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63037070 | Jun 2020 | US |