Anti-freezing agent and application of anti-freezing agent to cement additive water aqua for well cementation in oil field

Abstract

The invention relates to application of an anti-freezing agent to cement additive water aqua for well cementation in an oil field. The anti-freezing agent comprises a) 20 to 80 weight parts of ethanol, b) 10 to 50 weight parts of glycol, 5 to 30 weight parts of sodium nitrite aqueous solution with solid content of 15 percent and / or d) 5 to 30 weight parts of sodium thiocyanate aqueous solution with solid content of 15 percent. The anti-freezing agent can effectively reduce the freezing point of the cement additive water aqua in the well cementation process, is effective within the wide range of pH value, and has high physical and chemical compatibility; and the anti-freezing agent improves the rheological property of a well cementation cement slurry system to a certain degree, does not influence important performance such as compressive strength, thickening time and the like and has the advantages of environment friendliness and the like.

Description

field of invention [0001] The invention relates to an antifreezing agent and its use in an oil field cementing admixture water agent. Background technique [0002] In the process of oil field cementing, different admixtures are often added to ensure the performance of the cementing slurry. Such as adding dispersant to ensure the rheology of cement slurry; adding fluid loss reducer to ensure the fluid loss of cement slurry; adding retarder or accelerator to ensure the thickening time of cement slurry. Cementing admixtures are mostly high molecular compounds or small molecular inorganic acids (salts) obtained through polymerization reactions. During the application of cementing admixtures, most of them appear in the form of water agents. During the transportation, use and storage of water agent, if the ambient temperature is too low, it will solidify, which will cause inconvenience in transportation and use during cementing construction, especially in cold oilfield areas in w...

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Problems solved by technology

[0011] As far as the current research situation is concerned, the main agent of antifreeze is still salt or alcohol, and the content of the research is mainly concentrated on the antifreeze of engines and roads at low temperatures. The laboratory test data show that the presence of chloride ions will corrode the cement stone; at the same time, NaCl, CaCl 2 Such inorganic salts usually affect the hydration law of cement slurry, resulting in abnormal thickening time of cement slurry and changes in compressive strength

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