Process for making upsets for oilfield drill pipe
Pipe to be upset is conveyed via walking beam though a series of induction heating coils and one end is heated to a maximum temperature of 2350 degrees F. Thereafter, a robot transports the pipe into a forging machine where the pipe end is upset in one or more die pockets. For those types of pipes where the pipe end temperature falls below an acceptable temperature during upsetting, the robot delivers the pipe end to an auxiliary induction heating coil and is re-heated to an acceptable forging temperature. The robot then transports the pipe back into the forging machine where the pipe end is forged to its final upset dimensions.
1. A manufacturing process for forming upsets on ends of drill pipe for those types of drill pipe requiring re-heating between second and third upsetting stages, comprising:
operating a first preheat coil to preheat a pipe end of the drill pipe to be upset in a first preheat coil;
walking the drill pipe to a second, primary heating coil;
bringing the pipe end to a forging temperature of 2350 ° F. max in the primary heating coil;
picking up the drill pipe from the primary heating coil position via a gantry robot;
transporting the drill pipe to a first position of a pipe upsetter device and inserting the pipe end into the first position of the pipe upsetter device;
cycling the upsetter device on the end of the drill pipe a first time;
transporting the pipe to a second position of the pipe upsetter device and inserting the pipe end into the second position of the pipe upsetter device;
cycling the pipe upsetter device on the pipe end a second time;
transferring the drill pipe to a reheat coil located between the pipe upsetter device and the primary heating coil;
re-heating the drill pipe end to the forging temperature in the reheat coil;
transporting the drill pipe to a third position of the upsetter device;
cycling the pipe upsetter device a final time; and
delivering the drill pipe for downstream operations.
2. The process of claim 1 , wherein a non-upset portion of the drill pipe adjacent to the reheat coil is air cooled during the re-heating.
3. The process of claim 2 , further comprising applying a generally circular air curtain to the pipe end during the re-heating between the second position and the third position of the upsetter device.
4. The process of claim 3 , wherein the air curtain supplied by a semi-circular air manifold having a plurality of air orifices spaced about its inner diameter is pressurized with compressed air, wherein the manifold is mounted on a face of the re-heat coil and the air orifices are spaced around the inside diameter of the manifold to deliver a flow of cooling air to the non-upset area of the drill pipe to the auxiliary induction heating coil.
5. A process for forming upsets on a pipe end of a drill pipe, comprising:
preheating the pipe end;
moving the pipe end into a heater to bring the pipe end to a forging temperature of above 2350° F.;
inserting the pipe end into a first position of a pipe upsetter device and cycling the upsetter device on the pipe end a first time;
transporting the pipe to a second position of the pipe upsetter device and cycling the pipe upsetter device to upset the pipe end a second time;
if the drill pipe requires a third upsetting then transporting the pipe end to a reheat coil located between the pipe upsetter device and the primary coil;
re-heating the pipe end to about 2350° F. in the reheat coil; and
transporting the drill pipe to a third position of the pipe upsetter device and cycling the upsetter device to upset the pipe end a third time.
6. The process of claim 5 , further comprising cooling a non-upset region of the drill pipe adjacent the pipe end while reheating the pipe end in the reheat coil.
7. The process of claim 6 , further comprising applying a generally circular air curtain to the pipe end during the re-heating between the second position and the third position of the pipe upsetter device.
8. The process of claim 7 , wherein the air curtain supplied by a semi-circular air manifold having a plurality of air orifices spaced about its inner diameter is pressurized with compressed air, wherein the manifold is mounted on a face of the re-heat coil and the air orifices are spaced around the inside diameter of the manifold to deliver a flow of cooling air to the non-upset area of the drill pipe to the auxiliary induction heating coil.
9. The process of claim 7 , wherein a robot then transports the drill pipe back into the at least one final die pocket of the upsetter device where the pipe end is forged to its final dimensions.