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Method for determining plastic volume shrinkage of cement paste

A volume shrinkage rate and determination method technology, applied in the direction of material inspection products, etc., can solve the problems of inability to simulate the bottom temperature and pressure conditions, inability to meet the research needs of anti-gas channeling, inability to accurately measure the shrinkage and expansion of cement slurry, etc.

Active Publication Date: 2015-03-18
SOUTHWEST PETROLEUM UNIV
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Problems solved by technology

At present, the experimental simulation test device is mainly used to test the volume shrinkage rate of cement slurry after solidification, that is, the volume shrinkage rate of cement stone after final setting, and there are few instruments for testing the volume shrinkage rate of cement slurry in the whole process of setting
In addition, due to the limitations of the existing test instruments that cannot simulate the temperature and pressure conditions at the bottom of the well, and cannot effectively isolate the pressurized medium from the cement slurry, the current experimental test on the volume shrinkage of cement slurry is still in the stage of exploration and development. It is not yet possible to accurately measure the shrinkage and expansion of cement slurry, which cannot meet the research needs of anti-gas channeling

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  • Method for determining plastic volume shrinkage of cement paste
  • Method for determining plastic volume shrinkage of cement paste
  • Method for determining plastic volume shrinkage of cement paste

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Embodiment Construction

[0092] Further illustrate the present invention below in conjunction with accompanying drawing.

[0093] A method for determining plastic volume shrinkage of cement slurry, comprising the following steps in sequence:

[0094] (1) Obtain relevant size parameters of casing and wellbore: casing inner radius r i =78.55mm, outer radius r o =88.9mm (d i =177.8mm), borehole radius r w =107.95mm (d w =215.9mm);

[0095] (2) Obtain the relevant mechanical parameters of casing and formation rock: elastic modulus E of casing case =206.9GPa, Poisson's ratio μ case =0.3, the elastic modulus E of formation rock f =13.84GPa, Poisson's ratio μ f =0.287;

[0096] (3) Determine the relevant working condition parameters of oil and gas wells: including well depth H=5085m, formation pressure coefficient P T =0.0225MPa / m, electric logging temperature T=122℃, drilling fluid density ρ d =2.30g / cm 3 , cement slurry density ρ s =2.35g / cm 3 , water-solid ratio w / s=0.263;

[0097] (4) Comb...

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Abstract

The invention discloses a method for determining the plastic volume shrinkage of cement paste. The method sequentially comprises the following steps of (1) acquiring relevant size parameters of a casing and a well; (2) acquiring relevant mechanical parameters of the casing and stratum rock; (3) determining relevant working condition parameters of an oil-gas well; (4) calculating a reservoir pressure and an initial fluid column pressure of the cement paste; (5) calculating an isothermal compressibility of the cement paste; (6) preparing the cement paste, performing a weight loss experiment, and determining the final setting time; (7) determining a pore pressure descending curve under the actual working condition according to the similarity comparison principle; and (8) calculating the plastic volume shrinkage of the cement paste. A plastic volume shrinkage mathematic model of the cement paste comprehensively considers the actual stress working conditions of the underground casing and the stratum and the weight loss performance of the cement paste, is simple in principle and simple in operation, is capable of effectively determining the plastic volume shrinkage change principle of the cement paste in a condensation process, and provides a scientific method for determining the plastic volume shrinkage of the cement paste.

Description

technical field [0001] The invention relates to a method for determining the plastic volume shrinkage rate of cement slurry in the well cementing process in the field of oil and gas field development. Background technique [0002] Cement slurry volume shrinkage refers to the total volume change of cement slurry in the process of gradually changing from liquid to solid under the temperature and pressure conditions at the bottom of the well after cementing, and in the whole process of later production. Studies have shown that the volume shrinkage of cement paste is mainly caused by the hydration reaction, because the volume of the hydrate generated by the hydration reaction is smaller than the mixed volume of water and cement particles. With the progress of the hydration reaction, the liquid cement slurry gradually solidifies into solid cement stone, which needs to go through four stages: liquid phase, gelation, solidification and hardening. Therefore, the volume shrinkage of...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01N33/38
Inventor 李进李早元郭小阳程小伟李明刘健辜涛黄盛林銮谢和
Owner SOUTHWEST PETROLEUM UNIV
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