Page 98 - Air and Gas Drilling Manual

3-26 Air and Gas Drilling Manual
The unique characteristic of this type of drill pipe is that it can be run in
compression in the same manner as drill collars. Most heavy-weight drill pipe is
fabricated in Range 2 and 3 API lengths. It is also available in custom lengths
shorter than Range 2. Heavy-weight drill pipe are available in 3 1/2 inch, 4 inch, 4
1/2 inch, and 5 inch, 5 1/2 inch, and 6 5/8 inch nominal outside diameters. Figure
3-21 shows two typical heavy-weight drill pipe elements standing in a regular drill
pipe rack in a drill rig. One unique feature of heavy-weight drill pipe is the wear pad
in the center of the element. The wear pad acts as a stabilizer and improves the
stiffness of the heavy-weight stand in the drill string and thus reduces the deviation
of boreholes.
Table 3-3 gives the dimensional and mechanical properties for Range 2 heavy-
weight drill pipe (tube body and tool joints).
Table 3-3: Range 2 heavy-weight drill pipe dimensions and mechanical properties
(courtesy of Smith International).