Heavy weight drill pipe was developed in the mid-1960s as an intermediate weight drill string member. It was originally developed for three reasons:
1. As a transition member to be run between heavy weight drill pipe and drill collars.
2. As a flexible weight member to be run in directional drilling.
3. As a weight member on small rigs, drilling small diameter holes.
More recently, with the advent of horizontal drilling, it has found a new application being used in the curved portion of the hole below the drill collars.
Heavy weight drill pipe is normally manufactured by attaching high alloy tool joints to a lower alloy tube. Figure 1 is a typical configuration. This attachment is normally done by inertia welding (although other methods have been used). Additionally, some heavy weight pipe has been produced using drill collar bar material and turning the bar to the finished dimensional profile.
It is manufactured primarily in three sizes: 3-1/2″, 4-1/2″, and 5″. Most manufacturers also make 4″ size, with some 5-1/2″ and even 6-5/8″ size. (The size represents the tube diameter.)
While being similar in appearance to drill pipe, heavy weight drill pipe has the following different dimensional characteristics:
1. The heavy weight drill pipe tube wall is heavier, being approximately 1″ thick on most sizes.
2. The tool joint(s) are longer.
3. The tube section has a larger diameter at mid length to protect the heavy weight drill pipe from wear.
4. Some manufacturers provide spiral grooving in this larger section. It is said that this promotes hole cleaning and resistance to differential wall sticking, among other
5. Hardbanding is normally standard on both box and pin tool joints with additional hardbanding on the center wear section.
6. API pin stress relief features and API boreback box stress relief features are normally standard on sizes above 3-1/2″.
Most manufacturers offer the following recommendations for running heavy weight pipe:
When run in vertical holes for weight:
1. Run the necessary number of joints to provide the required weight plus enough more joints to ensure the transition point stays in the heavy weight pipe.
2. Do not run in compression where the hole size is more than 4″ larger than the heavy weight tool joint size.
When run in the transition zone between heavy weight drill pipe and collars:
1. Run a minimum of 18 to 21 joints.
2. Utilize the manufacturer’s recommendations for the maximum drill collar size to be run below the heavy weight.
When run in directional holes for weight:
1. Run the necessary number of joints to achieve the desired weight on bit. (It is not uncommon to run as many as 60 joints in this application.)
R.K. Pipe sells a wide variety of new and used drilling equipment including tubular products (drill pipe, drill collars, heavy weight drill pipe, spiral weight, etc.), pipe handling equipment (rotary tables, bushings and slips, elevators, tongs, kellys, blocks, swivels and hooks, etc.), blowout preventers, mud pumps, and many other items. We handle equipment from multiple manufactures including Gardner Denver, National Oilwell, EMSCO, IDECO, MKP, BJ, WEB WILSON, VARCO, BASSH ROSS, AOT, WOOLEY, DM, GLOBAL, and others. Please check our online inventory for a full list of what R.K. Pipe has in stock.