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Sucker rod constructed of FRP (fiber-reinforced plastic) is currently used in offshore oil and gas industries due to its high tensile strength, lightweight, and resistance to corrosion. Due to the fact that the surface of FRP sucker rod cannot be threaded, it is often attached to steel joints via adhesive technology, and the bonded joint of FRP sucker rod is particularly prone to breaking and coming off. The current research is primarily concerned with the mechanical properties of FRP sucker rods, with little emphasis on the adhesive performance of bonded connections. This research developed a numerical model with a novel bonded joint structure based on the cohesion failure criteria. An indoor test was used to determine and confirm the expected bonded joint failure load. Additionally, an orthogonal test was conducted to maximize the adhesion performance. The findings indicated that a) theaccuracy of numerical model was within 2% and b) when the groove angle was 30°, the length ratio was 2/23, each groove was 14 mm in length based on a triangular groove, and the anticipated failure stress of the bonded joint was around 443 kN, an increase of 10%. [ABSTRACT FROM AUTHOR]

At present, fiberglass sucker rod has been gradually utilized in low permeability reservoirs because of their high strength and strong corrosion resistance. However, the bonding joint of fiberglass sucker rod in high water-content well is particularly prone to break and fall off, which influences the service life and construction safety of recovery operation. Current researches mainly focused on the bonding strength at room temperature, and less consideration was given to the residual strength and failure pattern under immersion. This paper proposed a novel diffusion-structure finite element model (FEM) based on transient dynamic method to simulate the process of water into the joint, and the life-death element method was adopted to study the progressive damage of bonding joints verified by indoor experiment in order to predict residual failure strength and obtain failure mode in submerged environment. As immersion duration extended, the results illustrated that a) the cohesive failure gradually became main failure; b) the maximum von Mises stress, shear stress, and end deformation of bonded joint increased and the maximum interfacial stress barely unchanged within the range of 5%; c) the numerically predicted strength decreased from 21.8 to 11.5 MPa, which was in good agreement with the experimental results within a deviation of 8%. [ABSTRACT FROM AUTHOR]