Patent Publication Number: US-7587923-B1

Title: Method of making a tubular

Description:
RELATED U.S. APPLICATIONS 
   Not applicable. 
   STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   Not applicable. 
   REFERENCE TO MICROFICHE APPENDIX 
   Not applicable. 
   FIELD OF THE INVENTION 
   The present invention relates to the forming and manufacturing of tubulars. More particularly, the present invention relates to the manufacturing of tubular products and tubulars having an upset formed on at least one end thereof. Furthermore, the present invention relates to techniques for marking such tubulars during the manufacturing process and during the forming of the upset of the tubular. 
   BACKGROUND OF THE INVENTION 
   Metal pipe, such as drill pipe, is normally assembled by joining adjacent lengths of drill pipe. The ends of the drill pipe are normally upset for welding to a threaded tool joint for connection of adjacent pipe lengths. The drill pipe lengths prior to forming of the upset ends and threads are of a constant wall thickness and have uniform inner and outer peripheries. A conventional method of forming an upset utilizes a die mandrel to form in a forging operation an external upset portion of increased wall thickness. Then, in a separate step with another die and mandrel, the end of the pipe is pressed or squeezed inwardly to form an internal upset portion. As used herein, the term “tubular” refers to green tubes, upsetted tubes, drill pipe, threaded casing, threaded tubing and tool joints. 
   Conventionally, it is important to be able to control the inventory of such pipe during the formation of the upset and subsequent to the formation of the upset. Whenever “green pipe” is received and throughout the upsetting operation, a bar code is applied to the outer diameter of this green pipe. The pipe is identified and orientation numbered by applying a bar code for traceability purposes. This bar code is applied with either paint or by the application of a label onto the outer diameter of the pipe. Such a bar code can correspond to heat, lot, purchase order number and pipe description. Once this bar code is applied to the outer diameter of the pipe, the information regarding the pipe can be stored in the computer system of the upsetting factory. As such, inventory control can be effectively maintained by the factory. A particular length of tubular can be continually monitored throughout the manufacturing process. 
   Unfortunately, in the manufacturing of present tubular products or other related steel products, it is impossible to paint a barcode and numbers with paint that is able withstand the severe thermal shock at the heat treatment portion of the manufacturing processes. The heat treatment process during the manufacture of the tubular will encounter temperatures as high as 1800° F. This tubular is then water-quenched with up to 300 p.s.i. of water pressure or severe oil quenched. Such heat treatment and quenching activities are carried out in order for the tubular, or other related products, to reach the proper physical properties for usage. At present, nearly all tubular products that go to heat treatment are hand-stamped at one end by several employees. This often develops a problem in that numbers are not stamped correctly. As a result, there is a loss of traceability. This can create problems for inventory control, customers, tracking, traceability, accounting, loss of production and for the waste of man-hours in correcting these problems. 
   It is an object of the present invention to provide a method of marking a tubular that increases the ability to trace the tubular during the manufacturing process. 
   It is another object of the present invention to provide a method of marking a tubular which improves the efficiency of the manufacturing process. 
   It is a further object of the present invention to provide a method of marking a tubular that enhances inventory control in the manufacturing environment. 
   It is another object of the present invention to provide a method of marking a tubular that reduces costs associated with the marking of the tubular and enhances the profitability associated with the sale of such manufactured tubular. 
   It is another object of the present invention to provide a method of marking a tubular which reduces human error. 
   It is a further object of the present invention to provide a method of marking a tubular that enhances the productivity associated with the manufacture of the tubular. 
   It is another object of the present invention to provide a method of marking a tubular that allows for instant data collection during the manufacturing process. 
   It is still another object of the present invention to provide a method of marking a tubular that enhances the ability to accurately cost the labor associated with the manufacture of the tubular. 
   It is another object of the present invention to provide a method of marking a tubular that is relatively easy to implement. 
   It is another object of the present invention to provide a method of having a barcode marked on tool joint 35° that will have all information of manufacturing process and description of both tool joint and tubular product all transferred by computer network. 
   These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention is a method of marking a tubular that comprises the steps of: (1) applying an identification indicia onto the outer diameter of the tubular; (2) forming an indicator onto at least one of the ends of the tubular such that the indicator corresponds to information in the identification indicia; (3) heat treating the tubular such that the identification indicia is diminished; and (4) reapplying the identification indicia onto the outer diameter of the tubular based upon the indicator formed on the end of the tubular. 
   In the present invention, the identification indicia is preferably a bar code. This bar code can either be a 2D matrix bar code or a any other barcode symoblogy. 
   In the present invention, an upset is formed onto at least one of the ends of the tubular. The step of forming an indicator includes applying the indicator on an end face of the upset or, alternatively, applying the indicator on an outer diameter of the tubular adjacent the end of the upset. The indicator is formed of by either laser-engraving the indicator, stenciling the indicator, pin dotting the indicator, or by affixing a tag that has the indicator formed thereon onto the end of the upset. 
   The step of reapplying the identification indicia onto the outer diameter of the tubular includes scanning the end of the tubular after the step of heat treating so as to store information from the indicator, and applying the stored information as a bar code onto the outer diameter of the tubular. The step of heat treating includes heating the tubular to an austenitize temperature, and quenching the tubular after the step of heating. The step of reapply includes printing the identification information onto the outer diameter of the tubular between the ends the tubular. 
   The end of the tubular can be machined so as to remove the indicator therefrom. The step of machining occurs after the identification information is reapplied to the outer diameter of the tubular. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       FIG. 1  is a perspective view showing a tubular having a bar code marked on an outer diameter thereof. 
       FIG. 2  shows the tubular of  FIG. 1  as having upsets formed at opposite ends thereof. 
       FIG. 3  shows a subsequent step of the method of the present invention in which the indicator is placed onto an end face of an upset at one end of the tubular. 
       FIG. 4  illustrates the tubular after the process of heat treating in which the identification indicia is diminished. 
       FIG. 5  illustrates a further subsequent step of the process of the present invention in which the identification indicia is reapplied onto the outer diameter of the tubular. 
       FIG. 6  shows a final step of the method of the present invention in which the end of the upset of the tubular is machined such that the indicator is removed therefrom. 
       FIG. 7  shows an alternative step of the method of the present invention in which the indicator is formed on a 35° taper area of a threaded connection of the tubular. 
       FIG. 8  is a perspective view of an alternative form of the present invention in which the indicator is placed on the outer diameter of the tubular adjacent to each of the opposite ends of the tubular. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to  FIG. 1 , there is shown the tubular  10 . The identification indicia  20  is located generally centrally on the pipe  12  between the ends  14  and  16 . This identification indicia  20  is a bar code which will contain information relating to the tubular  10 . This information can be in the nature of heat numbers, lot, purchase order number, pipe description and pipe condition. The pipe description can be in the nature of describing the length of pipe  12 , the diameter of pipe  12 , the wall thickness of pipe  12  and the type of steel used for the pipe  12 . Additionally, such identification indicia  20  can also be indicative of the manufacturer of the tubular  10 , the location of the manufacturer, and other detailed information. The application of such the identification indicia  20  onto the outer diameter of the pipe  12  is presently carried out conventionally in manufacturing operations. 
   In  FIG. 2 , it can be seen that the tubular  10  has a first upset  22  that is formed adjacent to the end  14  and an upset  24  that is formed adjacent to the end  16  of pipe  12 . The upsets  22  and  24  are formed in a conventional upset forming process. The upsets  22  and  24  have a greater wall thickness and serve to form connectors for joining the tubular  10  to an adjacent tubular. The identification indicia  20  remains on the outer diameter of the pipe  12  generally centrally between the ends  14  and  16 . 
   In  FIG. 3 , the tubular  10  enters another stage in accordance with the method of the present invention. The information from the identification indicia  20  is now formed as an indicator  26  on the end face  28  at the end  14  of the upset  22 . The indicator  26  contains information which corresponds to the information from the identification indicia  20 . The indicator  26  can be laser engraved, plasma sprayed, stenciled, pin dotted, scribed or otherwise engraved onto the end face  28 . Alternatively, the indicator  26  can be in the form of a metal tag that has the indicator information imprinted or formed thereon. The metal tag can then be tack welded or otherwise secured onto the end face  28  of the tubular  10 . 
   In  FIG. 4 , the tubular  10  is illustrated after being subjected to heat treatment processes. As can be seen in  FIG. 4 , the identification indicia  20  has been diminished as a result of the heat treating process. As used herein, the term “diminished” means that the bar code associated with the identification indicia  20  is no longer readable or, at least, quite difficult to read. Since typical bar codes associated with the identification indicia  20  cannot withstand the high temperatures and quenching process associated with heat treating, such a identification indicia  20  will inevitably become damaged. As a result, it is not easy to read or receive information from the diminished identification indicia  20 . Fortunately, however, the indicator  26  still remains intact on the end face  28  of the upset  22 . Unlike prior art process, the indicator  26  is dot pin or pin dotted using computer processes. In other words, in order to apply the indicator  26 , it is only necessary to scan the bar code associated with the identification indicia  20  and program the computer so as to dot pin or pin dotted the indicator  26  on the end face  28 . In this manner the indicator  26  will withstand the heat treatment and quenching processes associated with the manufacture of the tubular  10 . 
     FIG. 5  illustrates the process the present invention after the heat treatment processes. As can be seen, the identification indicia  20  has been reapplied onto the outer diameter of the pipe  12  of tubular  10 . The bar code of identification indicia  20  is easily applied by reading the information on the indicator  26  at end face  28  of upset  22 . The bar code  20  can be reapplied by painting, labeling or other techniques described herein above. 
   In  FIG. 6 , the upset  22  of tubular  10  has been subjected to additional machining processes. Conventionally, after forming the upset  22  and during the machining to the tubular  10 , the indicator  26  is machined off the end face  28  of upset  22 . Since the bar code associated with identification indicia  20  remains, the tubular  10  can continue to be identified throughout the manufacturing process. 
     FIG. 7  shows the application of the indicator  40  onto the 35° taper area of tool joint  44 . As used herein, the tool joint  44  is a “tubular” onto which the indicator  40  can be applied. The indicator  40  is applied adjacent to the end  48  of the tool joint  44 . The opposite end  42  is a threaded connection that extends outwardly from the body  46  of tool joint  44 . The indicator  40  should have information corresponding to the identification indicia formed on the body  46  of tool joint  44 . The indicator  40  is in the form of pin dotting. 
     FIG. 8  shows that the process of the present invention is equally applicable to a straight tubular product such as tubular  50 . Tubular  50  has a first end  52  and a second end  54 . The identification indicia  56  is formed on the outer diameter of the tubular  50  between the ends  52  and  54 . The indicator  58  is formed adjacent to the end  52  but on the outer diameter of the tubular  50  adjacent to the end  52 . Indicator  60  is formed on the outer diameter of the tubular  50  adjacent to the end  54 . The application of the indicators  58  and  60  on the outer diameter of the tubular  50  can also be incorporated into the forming of the upsets on the tubular. Within the concept of the present invention, the indicators can be formed on either the end face of the upsets or on the outer diameter of the tubular adjacent to such end faces. 
   The present invention is particularly applicable, but not limited to, to the entire process of bar coding the tubular upset pipe. In conventional processes, the “green pipe” is delivered to the factory. The pipe is identified and numbered by applying a bar code for traceability purposes with paint or a label on the outer diameter thereof. The pipe is inspected by scanning the outer diameter of the pipe. The pipe is stored prior to the step of upsetting. During the upsetting process, pipe is loaded on an incoming upsetter rack so as to upset one end and scan the outer diameter thereof. The pipe is then preheated. Ultimately, the pipe is heated to the upsetting temperature while the outer diameter of the pipe is suitably scanned. The upsets are then formed on the pipe. The upset is then properly inspected. The pipe is then turned around and loaded on an incoming upsetter rack for upsetting the second end of the pipe. Once again, the second end of the pipe is preheated and then heated to the upsetting temperature. After forming the upset, the pipe is then stored so as to be ready for heat treatment. 
   During the storing of the pipe, the bar code information from the outside diameter of the tubular can be transferred as a bar code to one end or both ends of the upsetted pipe, this is carried out by a computer network. The bar code is applied by laser, stencil, pin dot, metal tag, scribing or any other type of permanent marking or engraved markings at both or one end of the tubular pipe. The tubular pipe is then loaded on an incoming rack for heat treatment. The end of the pipe is scanned before entering the austenitize furnace. The end of the pipe, with its markings, may be scanned after heat treatment. The end of the pipe may be further scanned before entering a tempering furnace. This end of the pipe may be further scanned after the tempering operation. Ultimately, the pipe is then stored. 
   After this storage of the pipe after heat treatment, the bar code information from one end or both ends of the tubular product is transferred to the outer diameter of the tubular by printing a bar code with paint and with the same product information from the end of the tubular product bar code by using a computer network. The outer diameter of the pipe can then be scanned and stored. 
   After storing, the pipe can be loaded on an incoming rack for machining the inside and outside diameters at the face of the pipe. As a result, the bar code markings on the ends of the tubular product are thereby removed. After the bar code on the ends of the tubular product are removed, the pipe is scanned on the outer diameter alone during the remaining processes of forming the tubular. 
   The paint used for the formation of the bar code of the identification indicia  20  should be printed with a paint that is able to withstand temperatures of up to 900° F. This will withstand the temperatures that occur during the internal coating that is baked onto the tubular  10  products and the temperatures associated with the heat experienced by the tubular during drilling activities. 
   The foregoing disclosure and description of the invention is illustrative and explanatory thereof. Various changes in the details of the illustrated construction can be made within the scope of the appended claims without departing from the true spirit of the invention. The present invention should only be limited by the following claims and their legal equivalents.