Patent Grant
8864428
Continuous rod is a long string of hardened, solid steel rod. The continuous rod was developed nearly 30 years ago for reciprocating pump applications where multiple-coupled sucker rods were typically used. Unlike separate sucker rods that couple together every 25 or 30-ft, the continuous rod only requires couplings at the top and bottom of the rod string. An early example of a unitary steel sucker rod string is disclosed in U.S. Pat. No. 3,923,469, which is incorporated herein by reference.
Today, operators can use continuous rod, such the COROD® brand of continuous sucker rod, for artificial lift systems, pump applications, and other well operations. (COROD is a registered trademark of Weatherford/Lamb, Inc.) The continuous rod (also called continuous sucker rod or coiled sucker rod) can be manufactured to almost any desired length. The rod is typically heat treated to a tensile strength of about 110-ksi, which corresponds to a Rockwell hardness value of about 26-HRc. Any hardness value above this may result in increased corrosion in an H2S environment.
The cross-section of the rod can be round or elliptical and can range in size from about 12/16-in to about 18/16-in. Both the round and elliptical rods can be used for reciprocating rod-pumping applications, but the round rod is better suited for rotary-type rod-pumping applications. Today, round rod is a necessary component to meet the high torsional needs of progressing cavity pumps. In fact, most of the continuous rod produced today has a round cross-section, and the demand for larger diameter rod continues to increase.
Due to its length, the continuous rod is coiled for storage and transport on a spool or reel. An early example is such a reel is disclosed in U.S. Pat. No. 3,504,866, which is incorporated herein by reference. For purposes of discussion,
As noted previously, continuous rod was originally developed to operate reciprocating downhole pumps. Because the continuous rod only needed to support reciprocating motion for these pumps, the rod did not require a specific cross-section. Therefore, manufacturers chose an elliptical cross-section for the rod, such as disclosed in U.S. Pat. No. 3,923,469. This elliptical cross-section ensured that the rod could be easily coiled on a reel without excessive bending stresses and then straightens itself after it was uncoiled.
The elliptical rod was used for a long time exclusively in North America and mainly in Canada. Accordingly, manufacturers configured a reel with an 18-ft (216-in) diameter based on Canada's transport regulations to store and transport rod. This 18-ft diameter reel, such as disclosed in U.S. Pat. No. 3,504,866, was large enough for coiling the rod on the reel 10 without excessive bending stresses, but was small enough to facilitate transporting the reel 10 under Canada's regulations.
Later, downhole rotary pumps were developed. Because these pumps are operated by rotation, the continuous rod used for these pumps needed a more round cross-section to handle torque. Naturally, manufacturers began storing and transporting this round rod on the 18-ft diameter reels 10 already existing in inventory. When coiled on these existing reels 10, however, the round rod experienced much higher bending stresses, and the outer skin of the round rod tended to yield. For example, round rod with a 1-in diameter coiled in one of these 18-ft diameter reels 10 can be significantly stressed and permanently bent because surface bending stresses can be as high as 138-ksi. Operators found that the yielding of the round rod coiled in the 18-ft diameter reel did not apparently affect the operation of the rod once deployed and straightened for use with a downhole rotary pump. Yet, further reduction in the 18-ft diameter of the conventional reels has not been sought or promoted due to the problems with yielding and bending stress. Accordingly, the current amount of bending of the round rod has become an expected consequence of coiling the round rod on the 18-ft diameter reels 10, and the round cross-section rod has been used with the 18-ft diameter reels 10 for many years.
Despite its usefulness and industry acceptance, storing and transporting continuous rod on the existing 18-ft diameter reels 10 can be expensive and time-consuming. Depending on where the rod is to be used, the reel 10 with the coiled rod may be transported on any number of trucks and ships and may pass through several areas of the world with different shipping and transportation requirements. In most places and especially Canada, the current 18-ft diameter used for the reels 10 limits the transportation of the continuous rod to truck mounted transportation. As expected, the size and weight limitations for truck-mounted transportation can be significant.
As one example,
Unfortunately, rail transportation of the 18-ft diameter reels 10 is not possible due to their size. In addition, the reels 10 must be shipped as bulk freight for overseas shipments, requiring special handling procedures and equipment. As expected, any long distance transport of these reels 10 can be very expensive, and the difficulties and expense involved in transporting the rod has limited its application and use in the industry.
In addition, the conventional reel 10 shipped with the coiled rod is a substantial inventory item. Therefore, the empty reel 10 must be returned to a facility for reuse. As expected, returning the empty reel 10 from a distant location to the manufacturing facility can still cost a considerable amount.
All of the required costs and travel time involved in transporting rod on the conventional 18-ft diameter reel 10 have been recognized in the industry for some time, but have simply become accepted. In fact, one recently recognized solution in the industry to overcome the problems with transporting continuous rod has sought to avoid the transportation issue entirely. For example, U.S. Pat. No. 6,481,082 proposes a technique for making continuous rod directly at the well site by welding individual, 40-ft lengths of straight round bar together on location to form the desired rod. In this way, the rod does not need to be manufactured at a facility and transported on a reel to the work site. Although this solution avoids the issue of transporting the continuous rod, it creates potentially new difficulties at the work site.
The subject matter of the present disclosure is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.
A continuous sucker rod transport system includes a reel having a cage and a removable hub. A support disposed about a center of the cage holds the continuous rod that has been coiled in the cage. In contrast to conventional reels, the cage has a diameter less than 18-ft (216-in) and preferably has a diameter of approximately 14-ft (168-in) or 11.5-ft (137-in).
The cage's support can have a plurality of support members. Each of these members can have an outer upright for holding the continuous rod disposed about the cage's outer perimeter. Each of the support members can also have an inner upright disposed about the cage's inner perimeter. These inner uprights can each have a foot at one end thereof and a head at the other end. In this way, cages can be stacked one on top of another by mating the heads of a lower cage into the feet of an upper cage.
The removable hub fits in the center of the cage. The hub has arms that extend from a central member, and distal ends of the arms removably attach to the support members on the cage. To achieve this attachment, the feet on the cage's inner uprights allow locks on the hub's arms to lock therein and attach the hub and cage together. The cage has shoulders and slots on the feet of its inner uprights. The arms' locks have fixed nubs that fit into the slots of the uprights. The locks also have levers that pivot on the arms to engage the shoulders on the uprights. An actuator, such as a pneumatic cylinder, piston, and spring can be used to lock/unlock the levers from the shoulders.
The cage can be transported with the hub removed. In addition, the cage can be supported in a space defined by an internal height and width of a flat rack container, such as a “super rack” container used in overseas shipping. In fact, two cages having a 14-ft diameter with coiled rod can be supported on stands in the container. Each stand can have angled walls for supporting the cage in a space defining a height less than or equal to 11⅓-ft (136-in) and defining a depth less than or equal to 7¾-ft (93-in). Alternatively, six cages having a 137-in diameter can be supported in the container. Either way, the cages fit into the envelope of the flat rack container, and this allows the stored cages to be handled and transported by rail and ship using the existing intermodal container system, which facilitates transport of the continuous rod to distant locations.
The foregoing summary is not intended to summarize each potential embodiment or every aspect of the present disclosure.
Referring to
The continuous rod is not shown for simplicity, although it is understood that the rod would be coiled around the cage 100 inside the support 102. As also shown in
1. Cage
Turning in more detail to the cage 100, the support members 110 are disposed about a center of the cage 100 for holding the coiled rod. Each support member 110 has an outer upright 120 toward the cage's outer perimeter and has an inner upright 130 toward the cage's inner perimeter. The outer upright 120 define an acute angle 122 and holds the spring bias of the rod when coiled in the cage 100. This angle 122 helps to layer the continuous rod at it is coiled inside the cage 100. Each of the inner uprights 130 has a foot 140 at one end (connected to the outer upright 120) and has a head 150 at a free end (separated from the outer upright 120).
Rings 160 disposed about the cage 100 attach to the uprights 120/130 and interconnect the support members 110 together. For example, one ring 162 attaches inside the outer upright's angles 122, and another ring 164 attaches inside the outer uprights 120 where they connect to the inner uprights 130. For additional support and to guide the rod, the cage 100 also has two rings 166/168 disposed about the free ends of the uprights 120/130. These two rings 166/168 define a circumferential slot for passage of the continuous rod into and out of the cage 100 during use.
The support members 110 can be composed of square, round, flat, or other shaped bars or rods that can be integrally formed or can be welded, bolted, or otherwise affixed together. Separate support members 110 tied together by interconnecting rings 160 is preferred to reduce the weight and cost of the cage 100, which may be reusable or may be an expendable component. However, the support 102 can use walls or other flat surface disposed about the outer perimeter of the cage 100 to hold the continuous rod if desired.
2. Removable Hub
As noted previously, the hub 200 has arms 220 that extend from the hub's central member 210 and that removably couple to the cage 100. As best shown in
The cage 100 can not only couple to the hub 200 as shown in
3. Removable Coupling Between Cage and Hub
The lock 240 on the arm 220 has parallel levers 242 on one side of the bar 224 and has an opposing lever 244 on the other side. These levers 242/244 pivot on a pin 246 disposed in the bar's pivot base 234. An upper pin 248 connects the distal ends of the levers 242/244 together, and an intermediate pin 243 is disposed between the parallel levers 242.
An actuator 250 pivotably extends from a shelf 223 on the lower bar 242 to the lock 240. The actuator 250 includes a cylinder 252 with a piston rod 254 extending therefrom and biased by a spring 256. Although shown unattached in
Initially, the lock 240 with its levers is pivoted upward from the bias of the spring 256. However, the slanted face of the shoulder 148 pushes the lock 240 when it hits the locking pin 248 as the cage (100) and hub (200) are brought together. When the foot 140 seats on the nub 232, the lock 240 is biased back to its upright position so that the locking pin 248 engages the perpendicular face of the shoulder 148. This coupling is done for each of the hub's arms 220 to each of the cage's feet 140 to connect the hub (200) and cage (100).
At this point, the location of the pivot 246 offset from the alignment between the foot 140 and nub 232 tends to force the lever arms 242/244 further onto the shoulder 148 if the cage (100) and the hub (200) move to separate from one another. In particular, the lock 240 is held on the shoulder 148 by the spring 256. The location of the pivot 246 with regards to the shoulder 148 on the upright 130 helps to draw the locking pin 248 into the inner upright 130 if the cage 100 is drawn off the hub 200. This helps ensure the engagement of the lock 248 on the shoulder 148 without the need for the application of force by the spring 256.
To uncouple the lock 240 and free the cage (100) from the hub (200), the lock 240 is pulled back from the shoulder 148 to release the cage's foot 140 to the hub's arm 220. This can be done manually using a tool or the like. Alternatively, as shown in
As shown in
Again, the lever arm 245 is held on the shoulder 148 by the spring 256, and the slant of the shoulder 148 can further pull the lever arm 245 toward the upright 130 if the cage (100) is drawn off the hub (200). To uncouple the lever arm 245 and free the cage (100) from the hub (200), the lever arm 245 is pulled back from the shoulder 148 manually using a tool or the like or using the actuator 250. As shown in
Although two locks have been disclosed for coupling the cage 100 to the removable hub 200, other forms of locks can be used. In general, the locks can use levers, latches, bolts, shoulders, ties, or other fasteners or mechanisms that removably interconnect portion of the cage 100 to portion of the hub 200.
Referring to
As also shown in
1. Cage
Turning in more detail to the cage 300, the support members 310 are disposed about the center 304 of the cage 300 for holding the coiled rod. Some of the support members (i.e., such as those labeled 311) are smaller than the main support members 310. Each support member 310 has an outer upright 320 toward the cage's outer perimeter to hold the spring bias of the rod when coiled in the cage 300.
Each outer upright 320 has upper and lower legs 322/324 extending from the ends of the uprights 320 toward the center of the cage 300. Preferably, these legs 322/324 are slightly angled from perpendicular to the upright 320, which facilitates stacking the cages 300 as described below. Rings 360 disposed about the cage 300 attach around the ends of the uprights 320 and interconnect the support members 310 together. In addition, upper and lower rings 362/364 attach around the upper and lower legs 322/324 to interconnect the support members 310 together.
The uprights 320 on the main support members 310 each have a foot 340 at one end and have a head 350 at the other end. In addition, the lower legs 324 on the main support members 310 each have a guide 325. The feet 340, heads 350, and guides 325 are discussed in more detail later.
As with the previous cage, this cage 300 defines a diameter less than 18-ft. Yet, this cage 300 preferably defines a diameter less than 14-ft and more preferably about 12-ft or 11.5-ft. Unlike the previous cage, the outer uprights 320 of this cage 300 do not define an angle so the outer periphery of the cage 300 is cylindrical. Lacking an angle to guide the rod naturally into layers into the cage 300, coiling rod into this cage 300 may require equipment to feed the rod into the cage 300 so that it layers neatly inside. To facilitate proper layering, this equipment may also load the rod into the cage 300 while the cage 300 is upright.
2. Removable Hub
As noted previously, the hub 400 has arms 420 that extend from the central member 410 and that removably couple to the cage 300. As best shown in
As best shown in
The hub's central member 410 can fit onto an axle or axis of handling equipment, and the reel 50B having the cage 300 and hub 400 can be rotated thereabout when coiling and uncoiling the rod. Therefore, the hub 400 can be used for handling the cage 300 in a manufacturing facility and at a work site, but can be removed for transporting the cage 300 by itself.
The cage 300 can not only couple to the hub 400 as shown in
Depending on the circumstances, two or more cages 300 can be stacked together as shown. Stacking of the cages 300A-B in this way can facilitate storage and handling of the cages 300A-B whether they have continuous rod coiled therein or not. This stacking also allows the cages 300 to be easily stored as inventory at a facility.
3. Removable Coupling Between Cage and Hub
Similar to previous locks, this lock 440 has a lever 442 pivotably connected to the upper bar 424. The lever 442 moves a cross pin 448 relative to a shoulder 348 on the support's leg 324, and an actuator 450 pivotably extends from the upper bar 424 to the lever 442. As before, this actuator 450 can have a cylinder 452 with a piston rod 454 biased by a spring 456.
As the cage (300) and hub (400) are brought together, the nub 432, if present, can insert into the upright's foot 340. Initially, the lever 442 is pivoted outward by the bias of the spring 456. However, the slanted face of the shoulder 348 pushes the lever 442 when it hits the cross pin 448 as the cage (300) and hub (400) are brought together. Eventually, the lever 442 is biased back to its upright position so that the cross pin 448 engages the perpendicular face of the shoulder 348.
At this point, the offset location of the pivot 446 tends to force the lever 442 further onto the shoulder 348 if the cage (300) and the hub (400) move to separate from one another. To uncouple the lever 442 and free the cage (300) from the hub (400), the actuator 450 pulls back the lever 442 from the shoulder 348.
Although this lock 440 uses a lever 442 and shoulder 348, other forms of locks could be used similar to discussed previously. As one additional example of a lock shown in
Turning now to
In addition to the benefits accrued from the modular nature of the disclosed reels 50A-B, the cages 100/300 have reduced size compared to conventional reels used in the art. As noted previously in the Background of the present disclosure, the conventional reel for storing and transporting coiled rod—even round rod—has an 18-ft diameter that has become the industry standard. As noted, the 18-ft diameter reel was initially suited for elliptical cross-section rod and Canada's transport regulations. Then, round rod developed later for rotary pump applications also used the existing 18-ft diameter reels, and the yielding produced in the round rod when coiled on these 18-ft reels simply became accepted. Therefore, the round rod has been used with the conventional 18-ft diameter reels for many years.
In contrast to this conventional size and despite the long-standing reluctance to coil rod about a smaller diameter, the cages 100/300 of the disclosed reels 50A-B have diameters less than 18-ft (216-in). For example, the cage 100 of
As a preliminary matter, the plastic strain resulting from coiling round rod on a conventional 18-ft diameter reel is about 0.5%, which has not caused performance problems so that the use of the 18-ft diameter reel for round rod has become accepted practice. Coiling round rod on as small as a 12-ft diameter would increase the plastic strain to about 0.7%. Although the increase in the strain is small (i.e., 0.2%), the cold work from coiling the rod on a smaller spooling diameter would be expected to adversely affect various properties of the round rod, which would be detrimental to the rod's performance. These affected properties relate to mechanical property changes, localized corrosion resistance, environmental cracking resistance, and high cycle fatigue.
1. Testing of Rod Coiled about Cage's Diameter
Accordingly, several tests were conducted to determine what effect reducing the spooling diameter from 18-ft to as small as 12-ft would have on the properties of round rod. These tests measured tensile properties, localized corrosion resistance, environmental cracking resistance, and high cycle fatigue life for continuous rod samples composed of 4120M and having a 1.15-in diameter. In all measured properties, there were no significant differences between rod samples subjected to the two spooling diameters of 18-ft and 12-ft. Accordingly, the tests unexpectedly showed that decreasing the spooling diameter for the round rod to as small as 12-ft would not adversely affect the rod's properties and performance despite the conventional expectation in the industry that detrimental yielding would result.
a. Sulfide Stress Cracking
In a first test, sulfide stress cracking (SSC) screening tests were conducted at room temperature to assess changes in the rod's resistance to environmental cracking in H2S containing environments. Different samples of rod were tested, including (1) rod as-manufactured, (2) rod as-coiled and straightened from the standard 18-ft reel, and (3) rod coiled (bent) over a 72-in radius mandrel 10 times and straightened to simulate the coiling and uncoiling of the rod on a 12-ft (144-in) spooling diameter.
Four-point bent beam specimens were machined from each of the test samples, and the test specimens were strain gauged in different H2S environments. The purpose of the tests was to determine whether there would be a difference in performance between the coiling diameters in an environment that more closely approximated a typical oil environment. None of the test specimens failed during the tests in the different H2S environment. In fact, no environmental cracking was detected so the rod was found to exhibit good resistance to sulfide stress cracking regardless of bending diameter (as low as 12-ft).
b. High Cyclic Fatigue
The most common failure mode for continuous rod is high cycle fatigue. Accordingly, high cycle fatigue tests were performed to assess changes in the fatigue resistance with respect to the spooling diameter as low as 12-ft. The fatigue tests were conducted using the standard 0.1 “R” ratio and high cycle fatigue specimens that are appropriate to the rod's geometry. As is known, the “R” ratio is the ratio of the minimum load to the maximum load. The specimens were curved such that the gage section that was fatigue-tested was near the OD of the rod along the plane of highest bending (outer radius). The samples tested were from the standard 18-ft spooling diameter and the smaller 12-ft spooling diameter.
The tests were conducted in air at various stress levels to determine the stress life relationship. The results indicated that there were no major differences between the tested samples having the standard 18-ft spooling diameter and those having the 12-ft spooling diameter.
c. Localized Corrosion
One of the known problems with cold work is the effect on localized corrosion. Previous study on tubulars that were cold strained by deformation indicates that the corrosion rate of the tubular's material is directly affected by the strain to which it has been subjected. Therefore, electrochemical tests were conducted on rods from the two spooling diameters of 12-ft and 18-ft by running a Tafel curve, resistance polarization, and cyclic polarization tests on these samples. The Tafel curve runs resulted in anodic and cathodic Tafel slopes and an average corrosion rate. In the end, the electrochemical tests performed did not reveal any significant differences in corrosion rates between the 18-ft and 12-ft spooling diameters.
2. Test Conclusions
As indicated above, the tests investigated tensile properties, localized corrosion resistance, environmental cracking resistance, and high cycle fatigue life of the rod having 12-ft and 18-ft spooling diameters. In all measured properties, there were no significant differences between rod samples subjected to the two spooling diameters.
The resistance to sulfide stress cracking was very good in that stress levels up to the yield strength exhibited no cracks. The actual environmental or material limits were not detected because no cracking was observed in any of the tests conducted. The results of the tests indicate that there are no significant differences between the 12-ft and 18-ft spooling diameters for the continuous rod.
Accordingly, the spooling diameter of the disclosed cages 100/300 can be less than 18-ft without adversely affecting the properties and performance expected from the continuous rod. In fact, the spooling diameter of the disclosed cage 300 in
With an understanding of how the cages 100/300 and hubs 200/400 couple together and the preferred diameters of the cages 100/300, discussion now turns to how the disclosed reels 50A-B can be transported and used.
1. Modular Transport
The cages 100/300 can hold the spring bias of the continuous rod once coiled therein. Because the hub 200/400 is removable, operators can transport coiled rod in the cage 100/300 alone without the removable hub 200/400. This reduces the total weight of what must be shipped to transport the coiled rod and greatly reduces the transportation costs.
The modular nature of the reels 50A-B can also reduces transportation cost because some components used to transport the coiled rod may be specifically expendable while other may be reusable. For example, the cages 100/300 may be an expendable transport component or could be reusable depending on transportation costs and where the rod is being shipped. In other words, the cages 100/300 can be lost packaging for long distance transport, but the cages 100/300 can be reused if returned to the manufacturing facility when economically feasible. The removable hubs 200/400, however, can be shipped separately from worksite to worksite and do not need to be shipped and returned with the cages 100/300.
Being smaller in diameter, the cages 100/300 are also more amenable to forms of transportation not available for conventional 18-ft reels used in the industry. For example, the smaller diameter cages 100/300 can be transported by rail and can require less space on a truck trailer.
2. Super Rack Transport
In another benefit, the smaller diameter cages 100/300 can fit inside a shipping container typically used for rail and oversea transport. This container is commonly referred to as a super rack container. Similar to the conventional flat rack container, the super rack container is available from Super Rack Global Pte Ltd. and disclosed in U.S. Pat. No. 6,227,397, which is incorporated herein by reference.
The super rack container is open an all sides, although it may have fixed or collapsible end walls. Unlike the conventional flat rack, the super rack container has telescoping corner posts that can extend to different levels. One available super rack container is the 40′ Highcube Super Rack available from Super Rack that has interior dimensions of 457.3-in (11.615-m) (L)×96-in (2.438-m) (W)×a height (H) ranging in 4 increments from 89-in (2.264-m) to 137-in (3.483-m). These types of super rack containers can be used by shipping services and carriers, such as the United Arab Shipping Company (UASC), Hanjin Shipping, Sarjak, HMM, STX Pan Ocean, etc.
Being able to fit inside such dimensions typically used for rail and oversea transport, the cages 100/300 can be transported by the intermodal transport system in an intermodal container by rail, ship, and truck. This form of transport does not require the cages 100/300 to be handled directly when changing from one mode of transport to another. Therefore, standard cranes and other handling equipment of the intermodal transport system can be used when transporting the cages 100/300 in the containers. Empty cages 100/300, if to be returned to a manufacturing facility, are preferably transported in the containers so they can be handled using the existing intermodal container system even when returned.
a. Intermodal Transport of First Reel
Stands 510A-B hold the cages 100A-B in the container 500. Each stand 510A-B sits on the platform 502 and has an angled wall 512 extending therefrom, which can be at an angle θ of about 60-degrees. The angled wall 512 supports the cage 100 thereon in a space defining a height (h) less than or equal to 137-in (i.e., about 136-in) and defining a depth (d) less than or equal to 96-in (i.e., about 93-in). In fact, the cage 100 may encompass a space having 92 7/16-in (d)×135 15/16-in (h)×168-in (w). As shown, the cages 100A-B can be transported without the hubs 200 disposed thereon, and ledges or shelves 514 may support the lower end of the cages 100A-B. Of course, ties, bolts, or other form of fastening can be used to affix the cages 100A-B to the walls 512 and/or platform 502 depending on the transportation needs.
Using the super rack containers 500, stands 510, and 14-ft diameter cages 100 without hubs 200 eliminates the need for specialized trailers and dedicated oversize permits along the shipping routes. Overall, this form of transport will reduce shipping costs significantly, as detailed below. Although shown without the hubs 200, transporting the cages 100 with the hubs 200 with the super rack containers 500 could also maintain reduced shipping costs. As such, the benefits of the smaller diameter cage 100 could be maintained even though the hub 200 is not removed or is not even removable.
b. Intermodal Transport of Second Reel
These cages 300 can be supported by triangular supports between the pairs and by chains and other conventional means for supporting cargo. Although shown without the hubs 400, transporting the cages 300 with the hubs 400 with the super rack containers 500 could also maintain reduced shipping costs. As such, the benefits of the smaller diameter cage 300 could be maintained even though the hub 400 is not removed or is not even removable.
3. Transportation Cost Reduction
The cost of transporting the continuous rod is expected to be significantly reduced below the current industry standard, and in some instances, the cost may be reduced by as much as fifty percent. The conventional shipping method uses the conventional 18-ft diameter reels that must be transported by truck on land. For overseas shipments, the conventional reels are break bulk and are stored below deck.
Using the disclosed reel 50A with 14-ft diameter cage 100 and removable hub 200, for example, a new shipping method can use super rack containers (500) that can be transported by rail and stored above deck on a ship.
As shown in Table 3 below, example cost for shipping two reels by the conventional method from Canada to Houston and then Houston to the Middle East may be about $12,500.00 per reel.
As shown in Table 4 below, example cost for shipping continuous rod by the new method from Canada to the Middle East may be about $6,250.00 per cage. This new method uses the cages (100) having the 14-ft diameter shipped with coiled rod without the removable hub (200). These cages (100) can be positioned on stands (510) and fit onto super rack containers (500), which can be carried like standard freight on rail lines, vessels, and the like. Using this new method, the shipping cost per cage is about 50% less expensive compared to the conventional method currently in use.
Each cage (100), however, for the new transportation method has about 20% less coiled rod compared to the conventional 18-ft diameter reels. Therefore, more cages (100) need to be shipped in order to transport the same amount of coiled rod. As shown in the cost analysis of Table 5 below, transporting forty conventional reels of coiled rod at $12,500 per reel may cost a total of $500,000 using the conventional method. Using the new method, forty-eight cages (100) must be used to transport the same length of rod. As can be seen by the difference in cost, however, even though more cages must be shipped, the new method still results in a total cost that is about 40% less than the conventional method.
Based on the cost analysis, reduced transport weight, reduced transport size, and other benefits outlined above, the disclosed reel 50 having the 14-ft diameter cage 100 and removable hub 200 represents a significant improvement over current industry practices for transporting continuous rod. Moreover, due to the long-standing use of the conventional 18-diameter reels and the reluctance to use any other transport method, the disclosed reel 50 having the 14-ft diameter cage 100 and removable hub 200 satisfies a long felt need in the industry to deal with the existing limits of transporting continuous rod. The use of the smaller diameter cages 300 of
Various measurements have been provided herein. Due to the nature of how the cages and removable hubs are made, the values of these measurements may vary within acceptable tolerances suitable to the constructed reel and its use. For example, measurements provided herein can vary by several inches either way, yet still be suitable for the implementation.
The foregoing description of preferred and other embodiments is not intended to limit or restrict the scope or applicability of the inventive concepts conceived of by the Applicants. In exchange for disclosing the inventive concepts contained herein, the Applicants desire all patent rights afforded by the appended claims. Therefore, it is intended that the appended claims include all modifications and alterations to the full extent that they come within the scope of the following claims or the equivalents thereof.
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| Entry |
|---|
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| Number | Date | Country | |
|---|---|---|---|
| 20110073552 A1 | Mar 2011 | US |
