Recyclable Fiber Reinforced Thermoplastic Sucker Rods for Improving Rod Pumping

Abstract

Sucker rods are an essential system component for artificial lift rod pumping or rod lifting of oil and gas wells, but they have been limited by use of metals and thermoset based non-metal composites (i.e., existing fiberglass sucker rods). Steel (metal) sucker rods have been limited, relatively, by a low corrosion resistance, a low strength to weight ratio (i.e., too heavy), a low fatigue endurance limit, and a low lifecyclei environmental, social and governance (ESG) rating. Composite thermoset glass fiber (fiberglass) sucker rods surround the fibers with a brittle epoxy resin matrix. They have offered a high strength to weight ratio and greater corrosion resistance but have been limited by a relatively low tensile modulus of elasticity (i.e., too stretchy relative to steel), a high cost (i.e., higher cost relative to steel), and a low mechanical toughness (i.e., low tolerance to compressional loads, high impact forces/loads and torsional shear forces). Metal end fittings have also been a costly challenge for thermoset composite rods. Composite thermoset sucker rods using carbon fibers have proposed a tensile modulus of elasticity comparable to steel but have been limited primarily by a very high relative cost to steel sucker rods and a relatively low mechanical toughness. Thermoset composites have shown to possess an operationally risky failure mode, as the material fails in a brittle manner with extensive fiber splintering commonly referred to as "broom sticking".