A Wellbore Instability Loading Experiment Platform and Its Loading Method

Abstract

The invention relates to a wellbore instability loading test platform and a loading method thereof, wherein the wellbore instability loading test platform includes a test piece, a loading system, and a detection system; the test piece is a simulated wellbore, and is cemented by a cement sheath and a casing Formed together, the loading system includes a loading platform, a radial loading cylinder assembly, an axial loading cylinder assembly, and a hot and cold water circulation injection system. Each radial loading cylinder assembly provides a radial load for the test specimen, and the axial loading cylinder assembly provides The test piece provides axial load; the cold water injection system simulates the high and low temperature environment of the wellbore in the formation. The detection system includes multiple stress and strain sensors, temperature sensors, pressure sensors, signal transmitters, computers, and stress and strain sensors. At the outer wall of the casing and at the inner and outer walls of the cement sheath. The invention can truly simulate the actual wellbore instability and destruction process, and can accurately and real-time monitor and detect the deformation and failure data of the cement sheath and the casing.

Description

Technical field: [0001] The invention relates to an experimental device and method in the field of oil and gas well engineering, in particular to a wellbore instability loading test platform and a loading method thereof. Background technique: [0002] The wellbore plays the role of isolating the formation and transporting oil and gas in oil drilling and production. The instability of the wellbore will lead to the production reduction or even scrapping of the oil and gas well, causing huge economic losses to oil and gas exploitation. The actual working environment of the wellbore is an oil and gas reservoir several thousand meters underground. The wellbore occurs in the formation. Due to factors such as formation factors, construction factors, and oil and gas exploitation, the load situation is very complicated. The existing technology cannot directly obtain accurate data. In order to solve common To solve the problem of wellbore instability, build a wellbore instability load...

AI Technical Summary

Problems solved by technology

[0004] Because the cement sheath and the casing have different deformation and recovery capabilities, under the condition of repeated changes in the temperature and pressure inside the wellbore, the deformation of the cement sheath and the casing is not coordinated, resulting in the destruction of the cemented surface, and the cement sheath first cracks or even breaks and loses its protection. Casing action, under the action of non-uniform load outside the wellbore, further casing deformation and damage

The deformation of the casing has the following types: buckling, shearing, collapse, a mechanical simulation casing confining pressure test device and its confining pressure method CN105606455 A, a test method for simulating the non-uniform collapse strength of a curved casing And device CN 105352807 A and bushing non-uniform external pressure loading test device and method CN 103308390 B both provide a device for applying non-uniform load on the outer wall of the casing, but there are deficiencies: the above three inventions realize a The application of non-uniform load can only simulate collapse deformation or bending deformation but not shear deformation. It does not consider the factors of casing internal pressure and temperature changes in actual working conditions, nor does it consider the effect of cement sheath, which is different from the actual downhole casing. The environment does not match

Apparatus and method for evaluating casing integrity in fracturing environment CN 106499385 A Considering the influence of casing internal pressure and temperature under fracturing conditions but unable to apply non-uniform load on casing outer wall

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