Urea modified carbon nanotube well cementation cement paste and preparation method thereof

Abstract

The invention discloses urea modified carbon nanotube well cementation cement paste which is prepared from the following raw materials in parts by weight: 100 parts of oil well cement, 1-2 parts of afluid loss agent, 0.02-0.15 parts of urea modified carbon nanotubes, 0.05-0.2 parts of a defoaming agent and 44 parts of clear water. The urea modified carbon nanotube is prepared by the following method: taking 1 part of a carbon nanotube, adding 10 parts of concentrated sulfuric acid and 30 parts of nitric acid, and performing mixing to obtain a solution A; carrying out ultrasonic treatment on the solution A at 140-150 DEG C for 3 hours, treating the solution A with a hydrogen peroxide aqueous solution with the mass fraction of 20% for 2-3 hours, performing centrifuging, washing the solutionA with distilled water until the solution A is neutral, carrying out suction filtration, and drying to obtain a solid S; sequentially adding 20 parts of acetonitrile and 1.2 parts of EDCI into the solid S to obtain a mixed solution B; adding 1.2 parts of urea and 2 parts of triethylamine sequentially into the mixed solution B, performing stirring for 2h at the room temperature, performing filtering and rotary evaporation to remove the solvent, recycling bottom-layer black solids, performing washing with deionized water, and performing drying. The mechanical property of the carbon nanotube well cementation cement paste is improved through the dispersity of urea modified carbon nanotubes in the well cementation cement paste.

Description

technical field [0001] The invention belongs to the technical field of cementing cement slurry, and in particular relates to a urea-modified carbon nanotube cementing slurry and a preparation method thereof. Background technique [0002] In recent years, in view of the rapid development of nano-materials, the use of nano-materials to improve the performance of cement stone is a research hotspot in the field of academia and cementing engineering. Carbon nanotubes are one-dimensional materials with high modulus and high strength. The diameter is generally several nanometers to tens of nanometers, the thickness of the tube wall is only a few nanometers, and the length can reach several microns. Research and practice have proved that carbon nanotubes can improve the mechanical properties of cement cement, but due to their relatively large length and diameter, entanglement between tubes is very easy to occur, which affects its effect. Therefore, for carbon nanotube cement slurry...

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Problems solved by technology

However, on the one hand, this method needs to carry out acyl chlorination of carboxyl carbon nanotubes, and then use glycine to modify them. There are many reaction steps and the reaction yield is limited; on the other hand, this method needs to use sodium bicarbonate aqueous solution to quench the reaction. , more raw materials, complex process

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