Fiber-reinforced composite coiled sucker rod and production apparatus and method thereof

Abstract

The invention discloses a fiber-reinforced composite coiled sucker rod and belongs to the technical field of oil production equipment in the petroleum industry. The fiber-reinforced composite coiled sucker rod has three structural layers stacked in order, namely an inner carbon fiber layer (A), an intermediate glass fiber layer (B) and an outer glass fiber layer (C) orderly from inside to outside. The inner carbon fiber layer is made of unidirectional carbon fibers arranged axially along a rod body. The intermediate glass fiber layer is made of H-grade glass fibers arranged transversely along the rod body and is bidirectionally wound or knitted to the inner carbon fiber layer. The outer glass fiber layer is made of unidirectional H-grade glass fibers arranged axially along the rod body. The sucker rod is made of resin matrix which is an epoxy resin system; the carbon fibers and the H-grade glass fibers are used as reinforcing materials. The invention further provides a production apparatus and method of the sucker rod. The sucker rod is good in corrosion resistance, has few connectors, is low in cost and low breaking rate, has slight piston effect and moderate modulus and is convenient to curl, transport, operate and use.

Description

technical field [0001] The invention relates to a sucker rod for industrial oil extraction, in particular to a fiber-reinforced composite material continuous sucker rod and a preparation device and method thereof, belonging to the technical field of oil production equipment in the petroleum industry. Background technique [0002] In the production of petroleum industry, the corrosion problem is an urgent problem to be solved in the oil field production process. The sucker rod is the key component connecting the oil pumping unit and the oil sucking pump. It is subjected to complex forces and has a harsh working environment. It is easy to be corroded and seriously affect its service life, causing great cost waste to oilfield production. Due to the characteristics of light weight, high strength and corrosion resistance, composite sucker rods have begun to gradually replace traditional metal sucker rods. The currently used composite sucker rods mainly include glass fiber reinfor...

AI Technical Summary

Problems solved by technology

[0003] FRP sucker rods are prepared by pultrusion of glass fiber reinforced thermosetting resin at one time, and have been widely used. However, with the continuous improvement of the reliability requirements of modern oil production, FRP sucker rods can no longer meet the requirements. The main problems are as follows: 1) The partial wear resistance of the sucker rod is not good; 2) The axial tensile modulus is low and the deformation is large, which leads to a significant reduction in the effective stroke of the oil well pump, and the oil recovery efficiency is significantly reduced; 3) The fiberglass sucker rods are all fixed in length, with A metal joint is used to connect the roots with the metal couplings used in metal sucker rods. Due to the complex structure, it is difficult to process. At the same time, each fiberglass sucker rod uses two metal joints, which is expensive; Compared with the traditional metal sucker rod, the material of the FRP sucker rod has been changed except for the rod body, and the other parts of the whole sucker rod string have not changed. There are many column joints in the traditional metal sucker rod, and the probability of breakage is high, and the piston effect Obvious issues such as not resolved

However, in practical application, it was found that the sucker rod adopts a one-time integral processing method of pultrusion and coating (including wire feeding-resin-impregnated-coating-coating-preforming-curing-coiling process), and the coating layer is fiber Fabric-reinforced thermosetting resin not only increases the material cost, but also the partial wear resistance of the fiber fabric coating is not ideal; There are problems such as uneven lap width, extrusion of internal unidirectional fibers, and low transverse strength; in addition, because the cross-section shape of the continuous sucker rod made of carbon fiber reinforced composite material is rectangular or elliptical, and its thickness is only 3-5mm, in When using special equipment for downhole operations, it is almost impossible to choose the material of the clamping part, and only two-piece clamping can be used, and the left and right directions cannot be limited, and it is easy for the rod body to deviate from the clamping part

Therefore, it is difficult to develop the structure and materials of the clamping part of the special downhole operation equipment, which has become a technical bottleneck in the application and limits the large-scale promotion and application of this product.

[0005] In addition, the Chinese invention patent CN201210501186.X discloses a fiber reinforced composite anti-eccentric wear continuous sucker rod and its preparation device and method. The fiber is only one kind of glass fiber, carbon fiber or basalt fiber, and the cross-sectional shape and size of the rod body are not specified. Because only a single longitudinal fiber is used, its transverse strength is low, and there are problems such as radial compression and poor bending performance; using a single glass fiber or Basalt fibers have low axial tensile modulus and large deformation, similar to FRP sucker rods, which will greatly reduce the effective stroke of the oil well pump and significantly reduce the oil recovery efficiency; using single carbon fiber, the cost of the rod body material is very high, increasing the axial At the same time as the tensile modulus, the flexural modulus also increases, resulting in difficult bending, which cannot meet the requirements of road transportation and operation, which limits its popularization and application

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