Preparation method of high-temperature-resistant great-temperature-difference cement paste for oilfield well cementing

Abstract

The invention relates to a preparation method of a high-temperature-resistant great-temperature-difference cement paste for oilfield well cementing. The high-temperature-resistant great-temperature-difference cement paste for oilfield well cementing is prepared from the following raw materials in parts by weight: 600 parts of Grade-G oil well cement, 30-36 parts of HS101L water-loss control agent, 8-20 parts of HS201L retarder, 1.8 parts of HS-301S dispersing agent, 150 parts of quartz sand, 30 parts of silicon micropowder, 1.8 parts of HS-XF1S suspension stabilizer, 280-300 parts of water and 1 part of sodium bis(2-ethylhexyl)sulfosuccinate. The particle size of the quartz sand is 80-120 meshes; and the particle size of the silicon micropowder is 300-400 meshes, and the silicon dioxide content is 90% or above. The preparation method comprises the following steps: adding liquid-phase raw materials into a paste mixing vessel, and uniformly mixing; and adding solid-phase substances into a solid-phase vessel, stirring uniformly, adding the solid-phase mixture into the paste mixing vessel, finally adding a defoaming agent, and stirring uniformly. The cement paste prepared by the method can be used under the condition of 50-180 DEG C, has outstanding resistance to great temperature difference, and can effectively avoid the phenomenon of super slow setting caused by great temperature difference.

Description

technical field [0001] The invention relates to a method for preparing a high-temperature-resistant and large-temperature-difference cement paste 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 flui...

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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