1. Technical Field
Embodiments of the subject matter disclosed herein generally relate to methods and systems and, more particularly, to mechanisms and techniques for handling heavy components of a device.
2. Discussion of the Background
During the past years, with the increase in price of fossil fuels, the interest in developing new production fields has dramatically increased. However, the availability of land-based production fields is limited. Thus, the industry has now extended drilling to offshore locations, which appear to hold a vast amount of fossil fuel.
The existing technologies for extracting the fossil fuel from offshore fields use a system 10 as shown in
However, during normal drilling operation, unexpected events may occur that could damage the well and/or the equipment used for drilling. One such event is the uncontrolled flow of gas, oil or other well fluids from an underground formation into the well. Such event is sometimes referred to as a “kick” or a “blowout” and may occur when formation pressure inside the well exceeds the pressure applied to it by the column of drilling fluid. This event is unforeseeable and if no measures are taken to prevent it, the well and/or the associated equipment may be damaged. Although the above discussion was directed to subsea oil exploration, the same is true for ground oil exploration.
Thus, a blowout preventer (BOP) might be installed on top of the well to seal the well in case that one of the above events is threatening the integrity of the well. The BOP is conventionally implemented as a valve to prevent the release of pressure either in the annular space between the casing and the drill pipe or in the open hole (i.e., hole with no drill pipe) during drilling or completion operations. Recently, a plurality of BOPs may be installed on top of the well for various reasons.
Such plural BOPs assembled together form a BOP stack. A traditional BOP stack may be tens of meters high and weighs tens of thousands of kilograms. Various components of the BOP stack need to be replaced from time to time. An example of the BOP 26 is shown in
However, the usage of the crane becomes impractical when plural BOPs are assembled to form the BOP stack. The BOP stack has a frame of its own that contains the multiple BOPs. However, the frame of the BOP stack also limits the accessibility of a crane to the BOPs. Further, as the BOPs are disposed on top of each other and one BOP may be as high as a few meters from the floor, it is impractical for maintenance personnel to directly access the BOP components (they are too high to be reachable) even when the BOP stack is in a maintenance facility. In addition, if the ram block has to be replaced while the BOP stack is in the field (e.g., deep under sea or when the BOP stack is brought on the maintenance vessel), it is difficult to use a crane attached to a solid base to remove various components of the BOPs with that crane in order to reach the ram blocks.
Accordingly, it would be desirable to provide systems and methods that avoid the afore-described problems and drawbacks.
According to one exemplary embodiment, there is a crane for moving a component of a device. The crane includes a supporting mechanism configured to be fixedly attached to the device, an arm mechanism connected to the supporting mechanism and configured to move in a horizontal plane, a sliding mechanism connected to the arm mechanism and configured to move substantially perpendicular to the horizontal plane, and a grabbing mechanism configured to be removably attached to the sliding mechanism and configured to grab the component of the device.
According to another exemplary embodiment, there is a blowout preventer (BOP) crane system for moving a component of the BOP. The BOP crane system includes a body of the BOP having a horizontal chamber; at least a ram block provided in the horizontal chamber and configured to move in the horizontal chamber; a bonnet configured to close the at least a ram block in the horizontal chamber; a supporting mechanism configured to be fixedly attached to the body of the BOP; an arm mechanism connected to the supporting mechanism and configured to move in a horizontal plane; a sliding mechanism connected to the arm mechanism and configured to move substantially perpendicular to the horizontal plane; and a grabbing mechanism configured to be removably attached to the sliding mechanism and configured to grab the component of the device.
According to still another exemplary embodiment, there is a method for handling a ram block of a blowout preventer (BOP). The method includes grabbing a bonnet of the BOP with a first tool attached to a crane, wherein the crane includes a supporting mechanism configured to be fixedly attached to a body of the BOP; moving an arm mechanism of the crane, which is connected to the supporting mechanism, in a horizontal plane to move the bonnet to uncover the ram block; storing the bonnet; replacing the first tool with a second tool, wherein the first and second tools are received by a sliding mechanism connected to the arm mechanism; connecting the second tool to the ram block; and lifting the ram block by actuating the sliding mechanism, which is connected to the arm mechanism, the sliding mechanism being configured to move substantially perpendicular to the horizontal plane.
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 exemplary 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 the terminology and structure of a BOP stack. However, the embodiments to be discussed next are not limited to these systems, but may be applied to other systems that require handling heavy components at certain heights above the floor.
Reference throughout the specification to “an exemplary embodiment” or “another exemplary 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 an exemplary embodiment” or “in another exemplary 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 exemplary embodiment, a crane may be attached to a BOP and can be configured to be able to reach the desired components of the BOP even when the BOP is assembled with other components in a BOP stack. This crane may be fixed to the body of the BOP and may be sized so as to allow it to reach the BOP stack and fetch, for example, the ram blocks of the BOP. The crane may be a jib crane in one exemplary embodiment to be discussed next. The crane may be manually, electrically, and/or hydraulically controlled by an operator. Various exemplary embodiments are discussed next for illustrating the features of such a crane.
According to an exemplary embodiment illustrated in
The spare holes 40 (i.e., the holes 40 that are not used to attach the hinge 38) formed in the body of the BOP 26 may provide the desired support for the crane. Once the crane is fixed to the BOP 26, the crane may be left assembled to the BOP even undersea, such that access to some of the components of the BOP is facilitated. The crane may be operable in the maintenance facility, on a vessel while the BOP stack is transported and also undersea. In one exemplary embodiment, each BOP of the BOP stack may have its own crane attached to its body. In another exemplary embodiment, the crane is a jib crane having a vertically moving component. A jib crane is defined in the context of this specification as a lifting device having at least one boom (jib) configured to move relative to a fixed base of the crane.
In an exemplary embodiment shown in
The supporting mechanism 62 may be a simply plate 64 that connects to the arm mechanism 70 with a pin 66. The plate 64 may have four holes 68 that correspond to holes 40 on the BOP 26. These holes 68 permit the entire crane 60 to be attached to the holes 40 of the BOP 26 with appropriate bolts, screws or other means known by those skilled in the art.
With regard to
In an exemplary embodiment, the arm mechanism 70 has between two and five arm components.
The sliding mechanism 80 is better illustrated in
The sliding mechanism 80 may further include a plate 87 that is attached to the sliding plate 86. The plate 87 may be connected to a supporting plate 88. The supporting plate 88 is configured to support, for example, the grabbing mechanism 90. The grabbing mechanism 90 may include a connecting part 92 (which may be a screw) and a tool 94. In one exemplary embodiment, the supporting plate 88 may have a slot 89 as shown in
In the exemplary embodiments shown in
According to another exemplary embodiment, the bonnet 36 shown in
The sliding mechanism 80 is configured to lift the ram block 30 from the supporting rod 32 such that once the bonnet 36 is open or unscrewed, the ram block 30 may be fully removed from the BOP 26. Although the entire discussion of the crane 60 has been centered on the BOP 26, the same is true for the BOP 28 or other BOPs that might be present in the BOP stack. Also, this discussion is valid not only for BOPs that are removed vertically from their supporting rods but also for those BOPs that are removed horizontally from their supporting rods.
Variations of the crane 60 discussed in the above exemplary embodiments may include, for example, making the crane 60 able to move in a plane other than the X-Y plane, using more arms for the arm mechanism, using other sliding devices instead or in combination with the illustrated sliding mechanism, and/or using differently shaped tools for achieving the movement of the ram block 30 and/or the bonnet 36.
Another variation of the exemplary embodiments is shown in
In another exemplary embodiment, the sliding mechanism 80 is provided with a power source 130 that provides power via a conduit 132 to the sliding mechanism 80 as shown in
In another exemplary embodiment, the crane 60 is attached to the BOP 26 such that the arm mechanism 70 extends substantially parallel to the piston rod 32, as shown in
According to another exemplary embodiment, the tool 94 may have, as shown in
According to an exemplary embodiment, a method for operating the crane when connected to a BOP is discussed with regard to
The disclosed exemplary embodiments provide a crane system and a method for moving heavy components of a BOP or other heavy devices. 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 to disclose the exemplary embodiments, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other example are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements within the literal languages of the claims.