The general sucker rod is connected by couplings with the up-linked polished rod to the extractor and the down-joint plunger to the pump, of which the function is to transfer the reciprocating motion of the suspension point of the surface extractor to the down-hole pump.
TheChina sucker rodis a steel rod with a solid circular section advantaged by a simple structure, an easy process and a low cost. Its dominant application is for the general sucker rod pumping.
In the match with various oils of high moisture content, heavy ones, high wax content and corrosive medium and specialized in the deep and the inclined well operation, China sucker rods are specific ones with different structures, materials and applications such as the ultra-strong sucker rod, the fiberglass sucker rod, the hollow sucker rod, the continuous sucker rod and so on.
In addition to the sucker rod string and couplings, there are a number of accessories, mainly to be:
(1) The polished rod. Top the sucker rod to connect the wire rope of the horse head with the down-hole sucker rod and to seal wellhead together with the packing. Therefore, it shall be of high strength and fine finish.
(2) The weight rod. Down equipped with the weight rod for large pumps, heavy oil and deep wells, the sucker rod is able to prevent its lower part from bending longitudinally, so as to reduce the risk of breaking off.
(3) The sucker rod centralizer. Centralize the sucker rod inside the tubing for inclined and cluster wells to minimize the wear, vibration and bending by the non-contact operation.
In addition, there are shock absorbers for vibration reduction, anti-release devices for loosening couplings prevention and so on.