Sucker Rod are high grade rods made up of solid steel that are used in oilfield well drilling and well workover operations. The length of sucker rod ranges from 25, 30 to 37.5 feet (approx. 7 to 11 meters). It is used to connect the reciprocating pumping unit i.e. jack pump which is installed at an oil well with the downhole components of pump at the bottom of the well. These sucker rods run inside the oil well through a tubing string and have threads at both ends. In order to increase the length of sucker rod, other sucker rod can be screwed up along the threaded portion of first sucker rod and so on.
There are two types of Sucker Rods commonly used in oil well drilling or well workover operations as specified by API 11B. They are:
- Solid Steel Sucker Rods
- FRP or Fiber Reinforced Plastic Sucker Rods
Both these types of sucker rods vary in lengths and diameter sizes. For example, solid steel sucker rods are generally available in the length of 25 and 30 feet and its diameter ranges in 5/8, 3/4, 7/8, 1 and 1 1/8 inches. Whereas FRP type sucker rods are available in 25, 30 and 37.5 feet long lengths and diameter ranges in 3/4, 7/8, 1 and 1 1/4 inches.
Sucker rods are also called as pony rods if the length is less than 25 feet.