A testing method and device for simulating thermal strength of casing of steam injection well

Abstract

A test method and device for simulating the thermal strength of steam injection well casing. (with external thread, air outlet and pressure gauge) and a casing fixed by a rigid screw rod (with internal threads matching the left and right plugs on the inner walls at both ends) are heated, and when heated to the simulated gas injection temperature, pass The air inlet of the left plug slowly injects inert gas into the casing, and at the same time, the strain gauge is used to record the casing strain and corresponding time under different gas injection pressures, and the relationship curve between gas injection pressure, casing strain and equivalent stress is drawn based on the test data , the internal pressure yield strength and hoop residual stress of the casing at this temperature can be obtained by calculation, and the internal pressure yield strength and hoop residual stress of the casing at different temperatures can be obtained by changing the gas injection temperature. The device is suitable for the test and research of the internal pressure yield strength of the casing of the steam injection well.

Description

technical field [0001] This patent relates to the technical field of oil and natural gas drilling engineering, in particular to a test method and device for simulating the thermal strength of steam injection well casing. [0002] technical background [0003] In the oil and gas drilling and production process, oil casing plays the role of protecting the wellbore, strengthening the well wall, isolating the oil, gas and water layers in the well and sealing various complex formations. However, in the thermal recovery process of high-temperature steam injection in heavy oil wells, the casing will be affected by the steam temperature and pressure at the same time, and the temperature and temperature changes have a greater impact on the internal pressure yield strength of the casing, which is mainly manifested in the following two aspects: Aspects: first, higher wellbore temperature affects material properties such as casing tensile yield stress, elastic modulus, and linear expansi...

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Problems solved by technology

[0004] At present, the experimental research on casing strength only stays at normal temperature and pressure conditions, and for the research on casing thermal strength and thermal stress under high temperature and high pressure, domestic and foreign scholars have done a lot of theoretical research based on empirical formulas, and established Corresponding calculation model, but due to the lack of verification of test data, the accuracy and reliability of the model calculation results need to be improved and perfected

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