Wide spectrum chlorine-free coagulation accelerating early strength agent for oil field oil well cement

Abstract

The invention relates to a wide spectrum chlorine-free coagulation accelerating early strength agent for oil field oil well cement. The early strength agent comprises the following raw materials in parts by weight: 1 to 1.5 parts of sodium salts, 1 to 1.5 parts of calcium salts, 1 to 1.5 parts of aluminum salts, and 1 to 1.5 parts of other materials, wherein other materials are one or more of hydroxyl apatite, meta-kaolin, magnesium trisilicate, magnesium oxide, strontium sulfate, strontium carbonate, strontium nitrate, lithium carbonate, and oxalic acid. The provided early strength agent is stable, and has an excellent coagulation accelerating performance and early strength property; the early strength is high, the strength development is fast, the thickening transition time and primary-final setting transition time are short; and the early strength agent is suitable for various cement slurry systems such as cement slurry system with a wide temperature range and large temperature difference, AMPS cement slurry system, and the like.

Description

technical field [0001] The invention relates to a broad-spectrum chlorine-free coagulation accelerator accelerator for cement used in oil field well cementing, and belongs to the technical field of early strength agents for cement used in oil field well cement. Background technique [0002] Due to the large land area of ​​China, the northeast, north, and northwest regions have long winter seasons all year round, so it is necessary to add early-strength agents and early-strength water-reducing agents to improve the early strength development of concrete. Early-strength agents and early-strength superplasticizers are often mixed in constructions where the winter temperature drops below 10°C in East China and South China. Early-strength admixtures are widely used in the production of concrete components in order to stretch steel bars as early as possible, speed up formwork turnover and pedestal utilization. According to statistics, the total amount of early-strength agents and...

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Problems solved by technology

[0006] 1. Most of the traditional early strength agents contain chlorine. Chloride ions will cause corrosion of the casing, which will easily lead to a decline in the strength of high-temperature cement stones and an increase in the permeability of cement stones;

[0007] 2. Not suitable for AMPS cement slurry system, it is difficult to shorten the thickening time of AMPS cement slurry system, even if the amount of early strength agent is greatly increased, it is difficult to shorten the thickening time;

[0008] 3. The thickening transition time and the initial and final setting transition time are long, which is not conducive to preventing oil, gas and water channeling;

[0009] 4. It is difficult to solve the problems of super-retarding cement at the top of wells with high temperature and large temperature difference, slow development of cement stone strength or low strength

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