Novel cement paste for well cementation

Abstract

The invention relates to novel cement paste for well cementation. The novel cement paste for well cementation is made from the following components of: by weight, 100 parts of hydraulic cement, 44 parts of water, 0.5-30 parts of a reversible latex powder and 0.2-0.5 parts of an antifoaming agent, wherein the reversible latex powder is prepared by spray drying of one component which can be selected from the group consisting of a natural rubber latex, SBR latex, a vinyl acetate-ethene emulsion, an organosilicon emulsion and a polyacrylate emulsion. The cement paste provided by the invention has excellent properties of controlling dehydration, preventing fluid channeling, improving mechanical properties of cement stone to prolong the endurance of the cement stone, reducing the permeability of the cement stone and raising the corrosion resistance of the cement stone. The above properties of the cement paste enable the cement paste to be applied in a plurality of cementing operations. The cement paste can be used to effectively improve the cementing job quality and raise the service life of the cement stone, and has an extensive application prospect.

Description

technical field [0001] The invention relates to an oil well cement slurry used in the field of oil field cementing and injection. Background technique [0002] The main purpose of the most widely used cement slurry in oil and gas well operations is to fill the annulus between the casing and the borehole wall interface. The cement slurry sets and hardens in the annulus to form impermeable cement stone. Its main functions are as follows: one is to support and protect the casing; the other is to isolate different layers in the well and prevent the fluids in different layers from channeling or flowing. [0003] The basic components of cement slurry are oil well cement and water. G-grade or H-grade oil well cement is generally used in cementing engineering to prepare cement slurry. The basic properties of cement slurry including fluidity and rheology, water loss, thickening time and compressive strength are adjusted by adding fluid loss reducing agent, dispersant and retarder,...

AI Technical Summary

Problems solved by technology

To make the cement slurry have multiple properties, the cement slurry composition needs to be mixed with multiple admixtures, and the required cement slurry performance is adjusted by testing the ratio of the admixtures, which results in many types of cement slurry composition. Complicated phenomenon, the admixtures are easy to interact with each other, and even the performance of each other is restricted. A certain performance of the cement slurry cannot be adjusted, so the debugging of the performance of the cement slurry becomes very difficult. When designing the dosage of each admixture, it is necessary A large number of test data are used to characterize to ensure that the performance of cement slurry meets the requirements of on-site operations and the safety of construction

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