A TRANSPORTATION CRADLE FOR TUBULAR GOODS
Field of the Invention
The present invention relates to apparatus for use in transporting tubular goods such as oil pipes. In particular, a cradle is disclosed to assist simultaneous manoeuvring of a plurality of tubular goods. Background to the Invention
The oil and gas drilling industry requires, at the drill site, large numbers of cylindrical tubular pipes, for example to direct the oil and gas being extracted and also to protect the bore holes and the pipe string within the bore holes. The pipes are formed of steel and specialist equipment is therefore required in order to move the pipes from the point of manufacture or storage to the in-use location and vice versa. Transportation is made more problematic by the circular cross-section of the pipe which makes efficient stacking difficult and also introduces a requirement to prevent the pipe from rolling.
One apparatus which has been in use for over 25 years has a framework which fits around a collection of pipes holding the pipes into position. In order to prevent the pipes from rolling against each other and causing damage a moulded element is integrally bound to the lower inner surface of the framework. The moulded element includes a series of concave channels which co-operate to provide a groove in which the pipe sits, isolated from its neighbours. A locking bar allows one face of the framework to be opened and closed to enable addition and retention of the pipes. An integral lock ensures that the bar is not released unintentionally.
The above apparatus has a number of disadvantages when in use. Firstly, the framework can only be properly used for one size of pipe. The user is therefore, if he wishes to use the framework safely, constrained to purchase and then retain close to the required use area, frameworks suitable for each size of pipe being used. This represents an increased financial cost to the user and also requires storage space to be put aside for the frameworks which are not in use. In a rig, particularly off shore, space is usually at a premium.
Secondly, the frameworks are subject to frequent mechanical impacts and can easily be damaged. The locks especially, due to their location and relative weakness are particularly prone to being damaged. Moreover, the moulds are also subject to frequent impact. When damage occurs which requires repair, the entire framework needs to be sent away for repair which can result in large loss of time.
In addition to the above, the prior art apparatus described cannot be used in both older and newer rigs due to the differences in design of the mouldings. Summary of the Invention
According to the invention, there is provided an apparatus for transporting tubular goods such as oil pipelines, the apparatus comprising: a framework having first and second support sides; a base cross-piece linking the support sides; a first base moulding, secured about the lower part of the base cross-piece, the first base moulding including a plurality of downwardly orientated concave recesses, regularly spaced from each other and so sized to retain a length of pipe, a second base moulding secured about the upper part of the base cross-piece, the second base moulding including a plurality of upwardly orientated concave
recesses, regularly spaced from each other and so sized to retain a length of pipe, one or more further, removably mounted mouldings having both upwardly and downwardly orientated concave recesses; a top cross-piece, removably securable to the support sides; a locking means to retain the cross-piece in position, the framework including lifting means enabling the framework to be moved between locations. The first base moulding is preferably releasably secured about the lower part of the base cross-piece.
The removal aspect of the first base moulding allows for more rapid maintenance which can therefore lower costs and also repair times. Moreover, different mouldings having different sizes of recess can be used, increasing the range of use for the rest of the framework and reducing capital outlay and storage costs for the user. Advantageously, the locking means is demountable. During usage, the locking means can easily be damaged due, for example, to impact from the tubular goods and therefore the demountable nature of the locking means speeds up replacement of damaged items. Preferably, the portion of the moulding between recesses has a convex cross- section of opposite curvature to the recess to enable a pipe to roll into the recess, and therefore into the correct position.
The framework preferably includes a plurality of vertically orientated channels, to retain the further, removably mounted mouldings. The channels, arrayed pairwise along the framework, enable the mouldings to be slid and retained in position.
The or each further removably mounted mouldings are optionally mounted about
A- a cross-bar, the ends of the cross-bar being housed within a channel. A channel further optionally includes securing means enabling a moulding to be firmly received. Advantageously, the framework comprises a plurality of framework sections to enable the length of a framework to be changed. Further advantageously, the apparatus includes end covers to cover the ends of the tubular goods and prevent ingress of dirt or water into the goods. The lifting means is optionally formed of 6mm, HEBlOO steel to provide improved strength.
Optionally, the mouldings are formed of Shore 95-98 polyurethane to minimise damage to the tubular goods and also provide a hard wearing surface.
The top cross-piece is advantageously hingeably mounted to one of the support sides for ease of usage.
Brief Description of the Drawings
The invention is now described with reference to the accompanying drawings which show by way of example only one embodiment of a framework. In the drawings: Figure 1 a is a section through a prior art framework;
Figure Ib is a section through a framework according to the present invention;
Figures 2a-c are respectively a section showing three tubular pipes within a framework, a top view of a framework section and an enlarged view of a lifting means;
Figures 3a & 3b are a side view of pipes in a framework and an end view of the view shown in Figure 3 a;
Figure 4 is a perspective view of an embodiment of a cradle;
Figures 5a and 5b are a side and perspective view of a door in a framework; and Figure 6 illustrates a channel-type housing for retaining mouldings.
Detailed Description of the Invention
Many areas of industry, but in particular the oil and gas drilling and supply industry require large numbers of tubular pipes to be delivered to and removed from a particular site. For example, when carrying out a drilling operation, a string is formed of individual pipes, which string is passed down into a bore hole. When the drilling or extraction process is complete, the string is removed and disassembled, with the individual pipes then being removed and prepared ready for re-use. It will therefore be readily seen that an efficient storage and transportation means is required to minimise the wastage of time and storage space. The problem of storage space is particularly acute when the drilling site is an off-shore facility where space is at a premium.
The prior art framework 10 of Figure IA represents one way of addressing the problem and has been in use for over 25 years. Using a suitably sized framework and components, length of pipe having diameters of from around 2-20"
(approximately 5 -50cm) can be transported. The frameworks in accordance with
Figure IA do however have a number of drawbacks. Firstly, the lower moulding
11 is integral with the bottom beam 12, which bottom beam 12 is itself integral with the side supports 13, 14. In the event of damage to the moulding 1 1 therefore replacement or repair is not easily carried out and the framework needs to be sent away to a specialist repair site.
In addition, the mouldings 11 are designed to cope with pipes having a narrow range of diameters. Therefore if a site is carrying out an operation involving different sizes of pipes then different frameworks will need to be kept available to
deal with each size. The expensive storage space required then obviously increases.
The invention therefore contemplates a framework as shown in Figure IB. The framework is able to be used in combination with a mechanised handling system as well as those conventional systems which utilise manual handling. The framework 20 has two side supports 21, 22 which act to retain the other elements of the framework 20 and also form a side wall for pipes contained within the framework 20, to prevent their falling out. The side supports 21 , 22 are connected together by a base beam 23. In addition to having a structural role, the base beam
23 provides support for mouldings 24, 25. The mouldings 24, 25 can be permanently attached to the base beam 23 with the base beam 23 being removably attached to the side supports 21, 22. Advantageously the mouldings 24, 25 are removably attached to or associated with the base beam 23. In the latter case, the base beam 23 can either be permanently fixed to or removably fixed to the side supports 21, 22.
Each moulding 24, 25 comprises one or more concave recesses 26a, 26b to retain and support a length of pipe 27. The width and depth of the recesses are selected to suit a particular pipe being stored and the number of recesses across the width of the framework is governed at least in part by the diameter of the pipe. It will be appreciated that where the opposite sides of a moulding have recesses of a different size then this enables pipes of different diameter to be housed within the same framework 20.
The framework 20 shown in Figure 2 has in addition, handling brackets 30, 31 shown in more detail in Figure 2C. The brackets 30, 31 are generally planar and have an aperture 49 allowing a lifting chain or rope 32 (Figure 3b) to be passed therethrough.
Further mouldings 28, 29 mounted about a cross-beam 23a, 23b respectively are then laid down over the top of any pipes 27 resting on the next lower moulding. In the exemplified embodiments the side supports 21 , 22 each include an inward facing channel 21a, 22a into which the cross-beams 23a, 23b, supporting the
mouldings 28, 29 can pass and be retained. The cross-beams 23a, 23b can be clamped, bolted or otherwise secured within the channels 21a, 22a, to support- means within the channels 21a, 22a, the position of said support-means being, in an unillustrated embodiment, adjustable along a channel 21a, 22a.
A final uppermost moulding 33 is located into place by a locking mechanism (not illustrated), typically by being bolted in position. This ensures that the pipes are firmly held and do not move around during transport. It is a feature of the present invention that the locking mechanism is demountable to facilitate the removal of a defective or damaged mechanism without the entire framework being sent away for repair. The top beam is secured to the side support by a 5/8" (1.6cm) bolt which also screws into the locking mechanism. When desired, the final moulding 33 can be hingeably mounted to the rest of a frame. Once the pipes have been loaded into position, the mouldings and the sides of the framework protect the pipe sections from damage due to impact.
A further feature of the invention is that the peaks 34 of the moulding are rounded, in contrast to those in the prior art which are flat (see 15, Figure 1). This feature ensures that if, on loading, the pipe is placed onto a peak 34, then it rolls into a recess 26 and does not remain on the peak 34 and so require manual manoeuvring.
In use therefore, and as illustrated in Figure 3A, a number of frameworks 40-43 are aligned. The frameworks 40-43 already have the lowermost mouldings secured in position about the bottom beam 12, and the alignment of the frameworks 40-43 is such that the recesses of the frameworks 40-43 correspond to each other to receive the pipes and retain the pipes parallel to each other. The pipes are lowered into position to form a first layer. A further moulding 28 is then placed over the pipes in the lower layer, and each of the frameworks 40-43 and further pipes laid into the upwardly oriented recesses of the further mouldings.
The process is repeated until the uppermost moulding 33, again in each
framework 40-43 is put into position and locked into place. If required, end covers 45, 46 are placed over the ends of the pipes to prevent dirt or water ingress.
The cradles as such, when fully laden are able to be stacked on one another with the downwardly facing concave recesses 26a of the uppermost cradle engaging around the upper surface of the top layer of pipes in the lower most cradle.
The cradle thus formed is ready to be lifted and lifting chains 47, 48 are passed through the apertures 49 in the brackets 30, 31 and secured to a suitable lifting mechanism of a type known in the art. Typically only the central two frameworks
41, 42 are employed for the lifting procedure, and only these frameworks need therefore have a bracket 30, 31 attached. The outermost framework 40, 43 function in this case as clamps to retain and support the pipes in position. The cradle together with the pipes can then be moved.
Figure 4 shows a further embodiment of a cradle 50, which includes four framework sections 51-54, each able to provide support for layers of four pipes. Strength and structural integrity is provided to the cradle 50 by the horizontal bars 55, reinforced by the diagonally orientated support bars 56. Cross-bars 57 provide strength across the width of the cradle 50. The cradle 50 is therefore a strong but relatively lightweight structure in which pipes can be safely transported.
In order to facilitate loading and unloading of pipes from a framework, a door can be included in the framework, typically in the central region. The basic feature of the door is that the sides of the framework can be moved such that the pipes stored in the framework are accessible from that side by means of a fork lift truck. Once the door is opened, the truck can be manoeuvred such that the tines, or suitably modified equivalent can be brought beneath a pipe or pipes to lift and remove the pipe(s) from the framework.
This is exemplified in Figures 5a, 5b, which show an embodiment of a door 61 in a framework 60. The door sections 62, 63 are such that they are removable when loading or unloading is to take place and securable to the framework 60 once this has finished. Conventional means, known in the art can be used to secure the
door 61, such as hinges, bolts, clamps etc.
It will of course be understood that the invention is not limited to the specific details described herein, which are given by way of example only, and that various modifications and alterations are possible within the scope of the invention.