Test method for interlaminar shear strength

Abstract

The invention discloses a method for testing the interlaminar shear strength, which comprises the steps of: 1) cutting out a plurality of samples with the same length from a composite material pipe in the axial direction, and testing the samples by a clamp detection mechanism and by dropping The tool detects the remaining pipes separately; 2) multiple samples cut out by the fixture testing mechanism are tested separately, and the maximum value of the pressure and the median value of the multiple samples are taken as the minimum interlaminar shear force F1; And the shear failure load F2 of the lost-hand joint is measured by the lost-hand tool; the interlaminar shear strength τ1 of the sample is calculated by the formula, and the shear failure strength τ2 of the lost-hand joint is calculated by the formula; 3) the relationship is calculated according to the formula Coefficient α; 4) Increase the safety factor β for downhole tools made of different composite materials, and obtain the pump pressure P when the downhole tool interlayer is damaged according to the formula, that is, the interlaminar shear strength; this test method can reduce the Completion construction failure caused by insufficient interlayer shear strength.

Description

technical field [0001] The invention relates to a testing method, in particular to a testing method for interlaminar shear strength of composite materials used for processing non-metallic downhole tools. Background technique [0002] With the large-scale development of unconventional oil and gas reservoirs and high temperature and high pressure oil and gas reservoirs, higher requirements are put forward for the performance of well completion tools. Compared with metal materials, non-metallic materials have the advantages of corrosion resistance, high strength, light weight, easy drilling and milling, and easy flowback. Since the 1990s, the technology of using non-metallic materials to manufacture downhole tools has developed rapidly. . When the domestic petroleum industry is developing downhole tools and selecting composite materials, it has been found that winding glass fiber reinforced composite materials have good prospects for making easy-to-drill and high-strength down...

AI Technical Summary

Problems solved by technology

[0004] At present, there is no test method for testing the axial interlaminar shear strength of wound composite pipes for making downhole tools, and according to the test method, it is judged whether the interlaminar shear strength of the wound composite pipes meets the requirements

In particular, pipes are affected by changes in processing parameters during the manufacturing process. For example, there are too many interlayer fiber bonding defects, resulting in interlayer shear strength that cannot meet the requirements. However, it is difficult to distinguish with the naked eye. If there is no test method for layer The misuse of such tubing due to testing for inter-interval shear strength can easily lead to failure of well completion construction

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