Evaluation device and method capable of eccentricity testing of cementation quality of well cementation first interface

Abstract

The invention discloses an evaluation device and method capable of eccentricity testing of cementation quality of a cement-casing interface. The cement-casing interface is a well cementation first interface. Currently, evaluation of the first interface only considers the cementation situation of the outer surface of a casing and a cement ring, however, in a realistic multi-drilled well bore structure, cementation exists between the inner surface of the casing and the cement ring, and the cementation quality between the inner surface of the casing and the cement ring also determines the success or not of cement ring sealing. Besides, when consideration is given to the inner and outer surfaces, consideration also needs to be given to the influence of eccentricity of the casing on cementation. Aiming at the problems, according to the solving scheme, the technology and working condition well cementation on the spot are simulated as far as possible, including forming of mud cake, washing, downhole maintenance of cement, downhole pressure and temperature and the like. The evaluation device and method capable of eccentricity testing of cementation quality of the cement-casing interface are high in simulation degree, can evaluate the cementation situation of the outer surface of the casing and the cement, can simulate the casing cementation situation of random degrees of eccentricity, and can simulate the plugging strength of slug injection of colloids of cement paste and the like. An experimental result and analysis can provide important reference for the evaluation of cementation quality of the well cementation first interface, provide important basis for an engineering design, and can be applied to the evaluation of cementation strength of other material systems and the casing as well.

Description

technical field [0001] This patent relates to the evaluation of the first cementing interface of oil and gas well cementing, that is, the casing and cement sheath interface. It can simulate the complete cementing process under high temperature and high pressure and the working condition of any eccentricity of the casing, and can use the gas channeling method to evaluate the casing. Cementation of the cement sheath on the inner and outer surfaces. Background technique [0002] The first interface of cementing is the cemented interface between the casing and the cement sheath. Its good cementation can effectively protect the casing and prevent formation channeling. If channeling occurs at the first interface, it will not only affect the safety of production, but also make the fluid in the formation directly contact with the casing, which will accelerate the damage of the casing and cause safety hazards in fracturing and acidizing measures. Therefore, it is of great significan...

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Problems solved by technology

Liao Hualin proposed a test device and experimental method for evaluating the cementation status by measuring the sealing properties of the cement sheath (Liao Hualin, Guan Zhichuan, Shi Yucai, etc. A simulation test device for the sealing properties of the cement sheath in oil and gas wells [P]. Shandong: CN204024635U, 2014-12-17.), the device and method are to test the channeling of two cemented interfaces at the same time, and it is impossible to distinguish and study which interface has channeling; Guo Xiaoyang proposed a high-temperature and high-pressure one-two-two A cementing ability evaluation device for a cemented interface (Guo Xiaoyang, Zhang Kai, Li Zaoyuan, etc. High temperature and high pressure cementing first and second interface sealing ability testing device and method [P]. Sichuan: CN104406910A, 2015-03-11.), the Although the mud cake is formed in the device, it does not reflect the drilling fluid circulation process. Although the confining pressure is applied in the device, the rubber sleeve on the core jacket blocks the seepage of the liquid, which cannot reflect the formation pore pressure. Instead, the confining pressure mostly acts On the core, the simulation effect is poor. At the same time, this device only measures the cementation between the outer surface of the casing and the cement sheath, ignoring the fact that the inner surface of the casing will also be cemented with the cement when there are multi-level casings and the cement has a return height. In addition, the device cannot evaluate the cementation of the first interface in the case of eccentricity

[0004] According to the current research, there is no device in the current research that can completely simulate the cementing process and evaluate the anti-channeling ability of the first cemented interface very accurately. In the case of cement, at the same time, the research on the first interface cementation evaluation device under the condition of casing eccentricity has not found

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