High-temperature sedimentation stability test device for cement paste

Abstract

The invention discloses a high-temperature sedimentation stability test device for cement paste. The high-temperature sedimentation stability test device mainly comprises a base support 25, a maintenance kettle 7, a paste cylinder 6, an upper pressure sensor 21, a lower pressure sensor 20, a temperature sensor 11, a control panel 8, a computer 9, a gas source 1 and a water source 2, wherein the paste cylinder is placed in the maintenance kettle; heaters 15 are arranged between the paste cylinder and the maintenance kettle; an outer magnet 23 driven by a belt pulley 22 is arranged in the kettle body; the temperature sensor is inserted into the maintenance kettle and connected with the control panel and the computer; an inner magnetic rod 12 of a driver at the upper part of the paste cylinder is connected with a mandrel 13; the outer magnet of the maintenance kettle drives the inner magnetic rod in the paste cylinder to rotate to drive a paddle 16 to stir cement paste in the paste cylinder; the paste cylinder is provided with the upper pressure sensor and the lower pressure sensor which are both connected with the control panel and the computer; a driver plug 10 is connected with the gas source through a pressure regulating valve 3; the maintenance kettle is connected with a water source. The high-temperature sedimentation stability test device is reliable in principle, reasonable in structure and simple and quick in test, and can measure the sedimentation stability of different cement paste systems in different high-temperature environments.

Description

Technical field [0001] The invention relates to a device for measuring the settlement stability of annulus cement slurry under high temperature conditions, which is suitable for the measurement of the settlement stability of drilling fluid during oil and natural gas drilling, especially for cement injection, cement squeezing, cement plug and cement slurry Measurement of the settlement stability of cement slurry during leak plugging and other operations. Background technique [0002] In cementing operations, the settlement stability of cement slurry is a more important indicator, especially the settlement stability at high temperature, which is an important factor affecting the quality of cementing. The American Petroleum Institute (API) has The amount of water is used as a measure of the stability of the cement slurry, and the amount of free water reflects the stability of the cement slurry from a macro perspective. But in fact, the density of the cement slurry under the free wa...

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Problems solved by technology

[0006] (1) The stability of the cement slurry cannot be truly reflected by the size of the free liquid in the cement slurry alone, and the error in measuring the water separation of the cement slurry is relatively large

[0007] (2) It can only reflect the settlement stability of cement slurry qualitatively, and cannot be tested quantitatively, nor can it test the change of stability over time

[0008] (3) It is impossible to simulate the downhole high temperature and high pressure conditions, and it is impossible to evaluate the stability of cement slurry under real formation conditions

[0011] (1) After using the joint for a period of time, the seal is prone to failure, resulting in grout seepage, and it is not easy to demould after the cement grout is solidified, and it is easy to produce adverse phenomena such as misalignment when the two half pipes are buckled;

[0012] (2) The single cylinder structure can only test one formula at a time, lack of comparison, so that the test results have certain limitations, and the space of the curing kettle cannot be fully utilized, and the test efficiency is low;

[0013] (3) The design of the inner diameter of the cylinder is small, the influence of the cylinder wall effect is greater, and the height of the cylinder is not enough, resulting in no obvious difference in the density gradient of the cement column in the cylinder, which increases the resolution accuracy and difficulty of the test;

[0014] (4) The test time is long, and the density difference of the cement column can only be measured after the cement slurry has solidified, and the test efficiency is low, especially for cement slurry with a long setting time;

[0015] (5) It is impossible to evaluate the stability under the real temperature and pressure conditions downhole

[0020] (1) The structure of the device is complicated, and the test steps using the device are rather cumbersome. It is necessary to saw the cement stone after each time the cement stone is solidified to measure the mass and volume of each section respectively. The experimental operation is inconvenient and is not conducive to popularization and application;

[0021] (2) Long test time

[0022] (3) It can only test the stability of cement slurry at a certain point in time, but cannot test the relationship of cement slurry stability with time

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