Drilling or Service Rig

The present invention relates to a drilling or service rig. More particularly, it concerns a hydraulic drilling or service rig for use in drilling or service operations on- or offshore, the rig being formed by a derrick structure projecting from a foundation. The derrick structure is arranged to receive a carriage, movable along the longitudinal axis of the derrick structure, for the attachment of a drilling or service device, the carriage being arranged to be moved, under the influence of at least one double-acting hydraulic cylinder, along the longitudinal axis of the derrick structure away from or towards the foundation of the rig, and the derrick structure being telescopically movable.

The object of the invention is to provide a transportable drilling and/or service rig, which is formed by a simple and flexible structure arranged to be operated at substantially any angle in the vertical plane and/or horizontal plane.

By the term drilling rig is meant, in this document, an apparatus, which is arranged to drill a hole through loose or firm masses by means of a motor, a drill string and a drill bit. By the term service rig is meant, in this document, an apparatus which is arranged to carry out at least one of the following work operations: snubbing, pipe-handling, workover, so-called plug and abandon, casing drilling and underbalanced drilling.

A relatively great number of types of drilling and/or service devices are known, arranged for on- or offshore use.

From the American patent U.S. Pat. No. 5,697,457 ('457) is known a mobile drilling rig, which is provided with a telescopic, multi-stage lifting cylinder, which is placed within a rectangular derrick. The drilling rig is arranged to be transported in a horizontal position on a vehicle and be brought into a vertical position at the drilling site.

From the European patent EP 0 148 588 ('588) is known a drilling rig which is arranged to be transported lying on a vehicle and be tilted up as required. A derrick in the form of a frame, on which a carriage may be moved up and down, forms the rig. The carriage is moved by a double-acting hydraulic cylinder, which is placed between the two legs of the frame.

From the American patents U.S. Pat. No. 6,068,066 ('066) and U.S. Pat. No. 6,343,662 ('662) is known a drilling rig which includes at least three load-carrying, telescopically movable derricks, there being placed in each of the derricks two opposite conventional hydraulic lifting cylinders which are interconnected and which may bring about movement of the derrick structure. On the derrick structure is placed a top structure carrying a laterally movable carriage. To the carriage there may be connected heave-compensating means in the form of hydraulic cylinders, which are connected to a top drive. The carriage may also be provided with devices for carrying out pipe handling.

There are several disadvantages related to the above prior art drilling rigs. In the '457 patent a telescopic cylinder is placed inside a derrick. This makes access in connection with necessary service and maintenance difficult. Further, the top drive will produce a torque as the load from the top drive works eccentrically to the derrick. This torque will produce increased friction between the inner and outer sections of the derrick. To compensate for some of this increased friction an extensive system of friction-reducing means is placed between the said inner and outer parts of the derrick. The drilling rig of the '457 patent is restricted to the use of just one hydraulic cylinder, which may be limiting to the capacity, both with respect to load and with respect to the extension that the cylinder may effect.

In the '588 patent is described a derrick which may be tilted from a horizontal into a vertical position. The derrick has a fixed extent longitudinally and, thus, may not be shortened or extended as required.

In the patents '066 and '662 mentioned above is disclosed a very extensive system constituted by three separate derricks which cannot possibly be used on mobile so-called modular rigs or land rigs, and which also cannot possibly be rotated in the vertical plane. With the solution described and shown, it is not possible for a push force to be applied to the drill string either, which is essential to the invention according to the present application.

The invention has as its object to remedy or at least reduce one or more drawbacks of the prior art.

The object is achieved through features as specified in the description below and in the Claims that follow.

In this document positional indications such as “upper” and “lower”, “bottom” and “top” or “horizontal” and “vertical” refer to the position of the rig in the figures that follow, which may also be a natural, necessary or practical working position.

In what follows, the terms “conventional cylinder” and “telescopic cylinder” are used extensively about the hydraulic cylinder or cylinders which is/are arranged to move the carriage along the derrick structure. By conventional cylinder is meant a cylinder which has only one piston rod, but which is preferably double acting and has different areas for the movements “in” and “out”. In a specialist environment this type of double-acting cylinder is often referred to as a differential cylinder. By telescopic cylinder is meant a differential cylinder formed by one or more piston rods, with or without pistons, built into each other. Each piston rod or piston represents one stage. A telescopic cylinder may thus have two or more stages.

In one aspect the present invention is formed by a drilling or service rig for use in operations on- or offshore, the rig being formed by a derrick structure which projects from a foundation, and which is arranged to receive a carriage, movable along the longitudinal axis of the derrick structure, for a drilling or service device, the carriage being arranged to be moved, under the influence of at least one double-acting hydraulic cylinder, along the longitudinal axis of the derrick structure away from or towards the foundation of the rig, and the derrick structure being telescopically movable. The connection between the carriage and the cylinder may be fixed or flexible.

In a preferred embodiment the at least one hydraulic cylinder is placed on an external side of the derrick structure.

In a further preferred embodiment the drilling or service rig is arranged to be tilted in the vertical plane from a position, in which the derrick is in a substantially vertical position, and into a position, in which the derrick is in a substantially horizontal position. The drilling and/or service rig, referred to, in what follows, as the “rig”, is preferably arranged to be operated in both these positions and in all positions between the said vertical position and the said horizontal position. This, together with the possibility of the rig to exert both a push force and a pull force on the carriage, provides the advantageous feature of the rig being usable for inclined drilling or for performing service activities in inclined boreholes. In a further embodiment the rig is arranged for drilling or performing service activities in a position inclined upwards, that is a position in which the drill bit or service device is working in an upward direction relative to the horizontal plane. This may be relevant in onshore drilling or service activities.

In one embodiment the derrick is provided with at least one conventional hydraulic cylinder in addition to the at least one telescopic cylinder.

The derrick structure of the rig may be formed by any structure known per se, which is arranged to absorb the forces to which the structure is subjected. In one embodiment the derrick structure is formed by a latticework structure. In an alternative embodiment the derrick structure is formed by at least one pipe profile. The pipe profile may be of any cross-sectional shape, such as, but not limited to, circular, oval, rectangular or polygonal.

In what follows, is described a non-limiting exemplary embodiment of a preferred embodiment which is visualized in the accompanying drawings, in which similar or corresponding parts are indicated by the same reference numeral, and in which:

FIG. 1 shows a perspective view of a derrick structure for a rig according to the invention, in which a carriage is slidably placed on the derrick structure, and in which the carriage has been brought, by means of two double-acting, telescopic cylinders, to an upper end portion of a telescopic portion of the derrick structure;

FIG. 2 shows the derrick structure of FIG. 1 in a front view;

FIG. 3 shows a cross-sectional view through the line A-A of FIG. 2;

FIG. 3
a shows, on a larger scale, a section C of FIG. 3;

FIG. 3
b shows a horizontal view through the line B-B of FIG. 2,

FIG. 4 shows, on a smaller scale, the derrick structure of FIG. 1 in an alternative embodiment with just one double-acting, telescopic cylinder, which is connected at its upper end portion to the carriage;

FIG. 5 shows a perspective view, seen at an angle from above and from the rear, of a telescopic derrick structure, in which an upper end portion of a conventional cylinder is fixed to an upper portion of the sliding portion of the telescopic derrick structure, and in which the carriage is arranged to be moved along the said sliding portion by means of two telescopic cylinders which are attached to a lower portion of the said sliding portion;

FIG. 6 shows a view of the derrick structure in FIG. 5, viewed from the front;

FIG. 7 shows a side view of the derrick structure, viewed from the left towards the right in FIG. 6;

FIG. 8 shows a view of the derrick structure of FIG. 5, viewed from the rear;

FIG. 9
a shows, on a larger scale, a section D of FIG. 7;

FIG. 9
b shows a horizontal view through the line B-B of FIG. 6;

FIG. 10 shows, on a smaller scale, a perspective view of a portion of a rig, in which a drill string is connected to a top drive which is placed on a carriage which has been moved, by means of two double acting, telescopic cylinders, near an upper portion of the derrick structure of the rig;

FIG. 11 shows a perspective view of an alternative embodiment of the rig of FIG. 10, the drill string being connected to a rotary table and a swivel fixed to the carriage;

FIG. 12 shows a perspective view of the rig of FIGS. 10 and 11, but the drill string is connected to a downhole motor;

FIG. 13 shows, on a larger scale, the rig of FIG. 12, viewed from above;

FIG. 14 shows, on a smaller scale, a perspective view of a rig according to the present invention, in which the rig is placed on a vehicle;

FIG. 15 shows a perspective view of a rig according to the present invention, which is placed at an end portion of a multi-joint arm connected to a caterpillar vehicle; and

FIG. 16 shows a perspective view of a rig structure according to the present invention, in which a pipe-handling tool is connected to the carriage of the rig.

In the drawings, the reference numeral 1 identifies a rig, which includes a derrick structure 3 and a carriage 7, which is arranged to be moved along the longitudinal axis of the derrick structure 3 by means of at least one hydraulic, double-acting telescopic cylinder 9, which is connected, at a lower end portion, to a foundation 11. At its upper end portion, the at least one telescopic cylinder 9 is connected to the carriage 7 at an attachment portion 13.

A person skilled in the art will appreciate that the rig 1 of the exemplary embodiments is only shown by means of principle drawings and that in a situation of use the rig must be connected to a hydraulics control system, known per se, and a power supply. The hydraulics control system is arranged to provide, among other things, synchronized movement of the cylinder pistons/piston rods in the configurations of the invention in which more than one cylinder of each of the telescopic cylinder and conventional cylinder types are used in parallel. Additionally it will be understood that in all figures the foundation 11 is connected to a stable base, which is suitable for carrying the loads transmitted from the rig 1.

In FIGS. 1-3 is shown a rig 1 of a configuration in which the derrick structure 3 is formed by a fixed frame 4, which is connected, in a manner known per se, to the foundation 11, and by a sliding frame 5 which is arranged to be moved along the longitudinal axis of the said fixed frame 4. In the configuration, which is shown in FIG. 1, among others, the carriage 7 is arranged to be moved along the longitudinal axis of the sliding frame 5 by means of two hydraulic telescopic cylinders 9. When the telescopic cylinders 9 are in their initial position, that is to say when the telescopic cylinders 9 have their smallest extent (not shown), the lower portion of the sliding frame 5 will preferably have been brought to bear on a portion of the foundation 11. At the same time the attachment portion 13 of the carriage 7 will have been brought to a portion of the sliding frame 5, which is substantially level with the top portion of the lower element of the telescopic cylinder 9. As the telescopic cylinders 9 are extended, the carriage 7 will be brought to bear on a top portion 5′ of the sliding frame 5 (see FIG. 3a), after which the sliding frame 5 will be put into a sliding motion along the fixed frame 4 until the telescopic cylinders 9 or the sliding frame 5 reach(es) their (its) outermost or most extended position. The slide guides between the carriage 7 and sliding frame 5 and between the fixed frame 4 and the sliding frame 5 are shown as an outer profile, which is complementary to an inner profile, the outer profile surrounding a portion of the inner profile. This is the simplest form of slide guides. However, a person skilled in the art will know of a wide variety of alternative slide guides that could be used to achieve sliding motion between the said carriage 7 and derrick structure 3. In one embodiment (not shown) of the present invention, the slide guides are provided with rolling devices, known per se, which considerably reduce the friction between the carriage 7 and the sliding frame 5 and between the sliding frame 5 and the fixed frame 4, and the rolling devices are able to absorb torsional forces from the drilling device in a simple manner.

By the use of at least one double acting, telescopic cylinder 9 the possibility is provided for force to be applied to the carriage 7 in both directions along the derrick structure 3. This is very useful in cases in which there is a need to apply, for example to a drill string (see for example FIG. 10), a compressive force exceeding the force produced by gravity forces acting on the movable parts of the rig 1 including the carriage 7, a top drive 17 and the weight of the drill string. In drilling or servicing activities, in which the rig 1 is in an inclined, in a horizontal or in an upwards-tilted position, the advantageous features of double-acting cylinders 9 will be obvious to a person skilled in the art.

Another substantial advantage of the present invention is that a drill string that has got stuck in the borehole may be subjected to a stroke, for example by means of a so-called “jar” to try to free the drill string. In such jar activity or jarring, the structure, to which the drill pipe is attached, is subjected to great loads. In prior art embodiments, in which a carriage is driven by means of, for example, a pitch rack solution; there is a great risk of damage being caused to the driving gear. By the use of hydraulic cylinders connected to a carriage, the loads will be dampened by the cylinders and the hydraulic system in a manner known per se, and damage to the structural elements is prevented, or at least substantially reduced.

By the provision of a telescopic frame 3 there is achieved the advantageous feature of the rig 1 being relatively small in its smallest extent, which may be of substantial importance, for example when the rig is being moved.

By letting the push and pull forces be transmitted directly from the double-acting, telescopic cylinders 9 to the carriage 7, to which the top drive 17 or other equipment (see FIGS. 11 and 16) is attached, the derrick structure 3 may be designed to absorb far smaller forces than known derrick structures, which may again lead to a simpler and economically more favourable structure. Weight and dimensions of a rig 1 are particularly important when the rig is to be used in areas of limited space and/or weight restrictions, and not least when the rig 1 is arranged to be mobile, and when there is a need to move the rig 1 on, for example, a public road network, in a terrain or in places where there is limited lifting capacity for lifting equipment in.

In a preferred embodiment the at least one double acting, telescopic cylinder 9 is articulatedly supported (not shown) on at least one of the foundation 11 or attachment portion 13.

In a most preferred embodiment both attachment portions 11, 13 are articulatedly supported. Other forces than tension and compression may thereby be substantially eliminated from being transmitted from the carriage 7 to the telescopic cylinders 9.

In the exemplary embodiments the carriage 7 is provided with slots 8 arranged to receive attachment means for attaching drilling and/or service devices to the carriage. The slots 8 provide the possibility of attaching both a drilling device and a service device, so that the carriage 7 may carry, at the same time, both a drilling device and a service device.

In FIG. 4 is shown an alternative embodiment of the rig 1 of FIGS. 1-3, in which the carriage 7 is arranged to be moved along the derrick structure 3 by means of at least one double acting, telescopic cylinder 9.

In FIGS. 5-9 is shown an alternative embodiment of a rig 1 in accordance with the present invention, in which the telescopic derrick 3 of the rig corresponds to the derrick 3 shown in FIG. 1. In FIG. 5 a conventional cylinder 15 is connected at its one end portion to a foundation 11. At its other end portion, the conventional cylinder 15 is connected to a top portion of a sliding frame 5, which is arranged to be moved along a fixed frame 4 which is secured, in a manner known in itself, to the foundation 11. A lower end portion of two double-acting, telescopic cylinders 9 is connected to the said sliding frame 5 by way of two cylinder attachment elements 18 which are fixed to a lower portion of the sliding frame 5. At their upper end portions, the telescopic cylinders 9 are connected to a carriage 7 by way of attachment portions 13 on the carriage 7. In an alternative embodiment (not shown) the cylinder pistons (top portions) of the telescopic cylinders 9 are attached to a top portion of the sliding frame 5, and cylinder attachment elements 18 fixed to the carriage.

From their initial positions, that is when the conventional cylinder 15 and the telescopic cylinders 9 of FIG. 5 have their smallest extents (not shown), the lower portion of the sliding frame 5 will preferably have been brought into abutment against a portion of the foundation 11. At the same time, the attachment portions 13 of the carriage 7 will have been brought to a portion of the sliding frame 5 substantially level with the top portion of the lower cylinder element of the telescopic cylinder 9. By an out-stroke or extension of the conventional cylinder 15, the sliding frame 5 will be moved along the fixed frame 4 in an upward direction from the foundation 11. As the telescopic cylinders 9 are fixedly connected at their lower end portions to a lower portion of the sliding frame 5, the telescopic cylinders 9 will be moved together with the sliding frame 5. As the telescopic cylinders 9 are extended, the carriage 7 will be moved along the sliding frame 5 until the telescopic cylinders 9 reach their outermost or most extended position, in which the carriage is preferably at a top portion of the sliding frame 5. In a preferred embodiment the telescopic cylinders 9 are arranged to be operated independently of the conventional cylinder 15.

The combination of a conventional cylinder 15 and double acting telescopic cylinders 9 has several advantages. For example, the heavy loads may be carried by the conventional cylinder 15, whereas the double-acting telescopic cylinders 9 may carry out relatively rapid low-strain movements. By heavy loads the double-acting, telescopic cylinders 9 may be locked hydraulically and/or manually. When there is a need for rapid movement of the carriage 7 along the derrick structure 3, the conventional cylinder 15 may be run at the same time as the double-acting, telescopic cylinders 9. This also provides the possibility of reducing the speed of the individual cylinder, but still maintaining a relatively rapid movement of the carriage 7.

The length of stroke of the double acting, telescopic cylinders 9 can be reduced in the embodiment shown in FIG. 5 compared to that of the embodiment shown in FIG. 1, for example. This is because the “range of operation” is divided between the telescopic cylinders 9 and the conventional cylinder 15. This may be economically favourable as a double acting telescopic cylinder is relatively more expensive to manufacture than a conventional cylinder.

Even though only one conventional cylinder 15 is shown in FIG. 5, it will be understood that more than one, and preferably two, conventional cylinders 15 can be arranged to move the sliding frame 5 relative to the fixed frame 4. Similarly, the telescopic cylinders 9 may be formed by just one double-acting telescopic cylinder 9.

In an alternative embodiment (not shown) the conventional cylinder 15 of FIG. 5 may be replaced by one or more double acting, telescopic cylinders.

In FIGS. 10, 11 and 12 is shown a rig formed by a derrick or frame structure 3, to which a carriage 7 is slidably connected as described above. The carriage 7 is moved along the frame 3 by means of two double-acting, telescopic cylinders 9 which are connected, at their lower end portions, to a foundation 11, and which are connected, at their upper end portions, to the carriage 7 by way of two attachment portions 13. In a preferred embodiment the cylinders 9 are articulatedly supported as described above. To the carriage 7 are attached different types of drilling devices 17 known in themselves, to which there is attached a drill string 19. In FIG. 10 the drill string 19 is shown connected to a top drive 17, and in FIG. 11 the drill string is connected to a swivel 17 and a rotary table 19′. In FIG. 12 is shown a downhole motor 19′″ placed in a lower end portion of the drill string 19.

In FIG. 13 is shown, on a larger scale, a view of the rig of FIG. 12, viewed from above. In the portions that are in sliding contact with the frame 3, the carriage 7 and the attachment portions 13 for the cylinders 9 are provided with bearing means 14, the purpose of which is to reduce the friction between the frame 3 and the carriage 7, and/or to reduce the wear resulting from the movement of the carriage 7 along the frame 3. In a preferred embodiment the bearing means 14 are formed by a synthetic material such as a suitable plastics material, but they may also be formed by metal or other suitable materials, which will be an expert choice. In an alternative embodiment (not shown) the bearing means are formed by rolling devices.

In FIG. 14 the rig 1 of FIG. 10 is shown placed on a trailer 30 of a vehicle 32. The rig is arranged to be rotated about an attachment portion 26 in a support element 28 from a first position (not shown), in which the frame structure 3 of the rig 1 is substantially parallel to the horizontal top surface 34 of the trailer 30, into a second position, in which the rig 1 is in a substantially vertical position. The rig 1 is rotated relative to the trailer 30 by means of a hydraulic lifting cylinder 20 known in itself, which is rotatably connected at a first end portion 22 to the top surface 34 of the trailer, and which is rotatably connected at a second portion 24 to a portion of the frame 3.

In FIG. 15 is shown the rig 1 of FIG. 10 placed on an end portion of a hydraulically controlled and articulated arm 42 projecting from a caterpillar vehicle 40. In the embodiment shown, at a portion of attachment to the vehicle 40, the arm 42 is arranged to rotate in a plane P in a manner known per se. The rig 1 is arranged to be rotated about a plane R about its portions of attachment to the arm 42 by means of an articulated connection 44 and a not shown hydraulic cylinder, known per se, which produces the rotation. With the embodiment shown in FIG. 15 it is possible to place the rig 1 in an upside-down position, in which the lower portion of the drill string 19 takes the highest elevation of the rig. This enables the drilling of a hole, in which the drill string 19 is run from a first position towards a second position of a, relative to the first position, higher elevation. The rig can also be configured for carrying out servicing activities instead of drilling activities.

It will be understood that any rig 1 shown or mentioned herein, is arranged to be rotatably connected to a mobile device such as the vehicle 30, 32 shown in FIG. 14 or to an arm 42 as shown in FIG. 15.

In FIG. 16 is shown a rig 1, in which a pipe-handling tool 50 of a kind known per se is connected to the carriage 7. The pipe-handling tool 50 carries two joined-together pipes 19. In the embodiment shown, the rig 1 is arranged to be rotated in the vertical plane by means of two hydraulic cylinders 52, and to be rotated relative to a supporting base 54 by means of a driving device not shown. Other service devices than the pipe-handling tool 50 or the drilling device or a combination these can also be connected to the carriage 7.

The present invention provides a transportable drilling and/or service rig exhibiting, relative to the prior art devices, sensational simplicity and flexibility, in which the rig is arranged to be operated at practically all angles in the vertical plane, while at the same time, by means of at least one hydraulic cylinder, the carriage may be subjected to a force in both directions, and in which, additionally, impact forces or so-called “jarring” may be transmitted to a drill string, for example.

Drilling or Service Rig

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CPC

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