High temperature and large temperature difference cement slurry for oil field cementing

Abstract

The invention relates to high-temperature-resistant and large-temperature-difference-resistant cement grout for well cementation in an oil field. The cement grout is prepared from components of raw materials in parts by weight as follows: 600 parts of G-grade oil well cement, 30-36 parts of an HS101L fluid loss agent, 8-20 parts of an HS201L retarder, 1.8 parts of an HS-301S dispersant, 150 parts of quartz sand, 30 parts of silica fume, 1.8 parts of an HS-XF1S suspension stabilizer, 280-300 parts of water and 1 part of bis(2-ethylhexyl) sulfosuccinate sodium salt, wherein the grain size of the quartz sand is 80-120 meshes, the grain size of the silica fume is 300-400 meshes, and the content of silicon dioxide is 90% or higher. Liquid-phase raw materials are added to a grout mixing container and mixed uniformly; solid-phase substances are added to a solid-phase container and stirred uniformly, the solid-phase mixture is added to the grout mixing container, finally, a defoaming agent is added, and the mixture is stirred uniformly. The cement grout can be used under the condition of 50-180 DEG C, has prominent large-temperature-difference-resistant performance and can effectively avoid a super-retarding phenomenon caused by large temperature difference.

Description

technical field [0001] The invention relates to a high-temperature-resistant and large-temperature-difference cement paste used for oil field cementing, and belongs to the technical field of petroleum drilling. Background technique [0002] The development of high-temperature deep wells is an important source of oil and gas production increase. The cementing technology matched with high-temperature deep wells also needs to be continuously developed and improved. As the most important part of cementing technology, whether cement slurry can meet the requirements of cementing construction and whether it can Later mining requirements have put forward higher requirements on the comprehensive performance of cement slurry. The function of cement admixture is to improve the performance of cement slurry, so that it can adapt to the cementing construction of high-temperature deep wells. At present, cement admixtures are mainly used for retarding, dispersing, and fluid loss reduction. ...

AI Technical Summary

Problems solved by technology

[0008] 1. The performance of commonly used cement fluid loss reducer will deteriorate under high temperature conditions, and the filtration loss will increase

At present, the commonly used cement fluid loss reducer is monomer or water-insoluble fiber as the main raw material of the fluid loss reducer. These fluid loss reducers are highly sensitive to temperature, water quality and cement particles, especially at temperatures > 100 ° C In addition, the thickening transition time of the cement slurry is longer than the 30 minutes specified in the relevant standards, and the anti-channeling performance is poor, which will cause the relatively active formation fluid to channel into the annular space. Bring opportunities to take advantage of, and bring hidden dangers to the guarantee of cementing isolation quality

[0009] 2. Existing retarders are sensitive to temperature and dosage, and have poor resistance to large temperature differences. The super-retarding phenomenon of cement slurry at the top of the sealing section is serious

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