Device and method for testing mechanical integrity of high-temperature high-pressure well cementation cement sheath

Abstract

The invention discloses a device and a method for testing the mechanical integrity of a high-temperature high-pressure well cementation cement sheath. The device comprises a cement sheath maintenance mould and a test working platform. The method comprises the following steps of (1) arranging an internal pressure casing into a hollow column formed by connecting left and right moulds, filling cement paste, and sealing upper and lower ends of the hollow column; (2) maintaining the cement sheath maintenance mould, taking the cement sheath and the internal pressure casing out, and putting the cement sheath and the internal pressure casing on the test working platform; (3) injecting water into an annular space of an annular pressure sleeve and a pressure bearing cylinder through an annular pressure inlet, injecting water into the casing through an internal pressure inlet, controlling the temperature at the target temperature, adjusting the annular pressure and the internal pressure to target pressure, recording the change of reading of a rotor flow meter, and showing that the mechanical integrity of the cement sheath is damaged at a time point that flow is obviously increased; (4) taking the cement sheath out, observing and detecting. The device and the method are suitable for simulating the damage and degradation of the cement sheath under different string structures in the later production process of an oil-gas well.

Description

technical field [0001] The invention relates to a cement sheath mechanical integrity testing device and method in the field of oil and gas well engineering cementing, in particular to a device and method for testing the mechanical integrity of the cement sheath under high temperature and high pressure conditions, which can simulate the double impact of the complex mechanical load and thermal stress on the formation and casing of the cement sheath, and can perform dynamic testing. Devices and methods for its mechanical integrity. technical background [0002] Oil and gas well cementing means that after the drilling operation reaches a certain depth, the casing is inserted into the wellbore, and the cement slurry is injected into the outer annular space of the casing to a predetermined position, so that it can be rapidly condensed and hardened within a predetermined time to form a high-quality, complete, The process of cement sheath with good interlayer isolation ability. The...

AI Technical Summary

Problems solved by technology

[0005] These research methods and means are all trying to simulate the real stress state of the cement sheath under the downhole working conditions, but there are also a lot of disadvantages

The software simulation data is calculated on the basis of a large number of simplifications, and the reliability of the data must be verified by equivalent physical experiments. The various cement sheath integrity simulators are actually only the measurement of "stone" and have not been realized. "Ring" structure, but the stress states brought by the two different structures are very different. More importantly, based on the limitations of experimental equipment and conditions, little consideration is given to the influence of cement sheath on high temperature, high pressure and the changes of the two. The stress impact of the cement sheath has not yet achieved a quantitative assessment of the mechanical integrity of the cement sheath

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