Compound low-density cement early-strength agent as well as preparation method and application thereof

Abstract

The invention provides a compound low-density cement early-strength agent as well as a preparation method and application thereof. The compound low-density cement early-strength agent consists of the following substances in percentage by weight: 70-90 percent of silicate, 10-30 percent of aluminate and 0.5-1 percent of triethanolamine. The compound low-density cement early-strength agent is good in compatibility, can accelerate hardening and condensation of low-density cement slurry, shorten the cementing and curing waiting time and effectively improve the low-density cement early strength. The compound low-density cement stone early-strength agent does not contain chloride ions and other corrosive ions, and has no corrosive effect on sleeves and cement tones. Adopted raw materials are more universal; the preparation method and required equipment are simple in conditions and are easy to implement. The compound low-density cement early-strength agent provided by the invention not only can meet performance requirements for the low-density cement slurry and the cement stones in the cementing construction, but also can effectively protect the sleeves, protect oil and gas reservoirs and improve the single well productivity. While economic benefits are obtained, the compound low-density cement early-strength agent also has obvious social benefits, thereby being worthy of popularization and application.

Description

technical field [0001] The invention belongs to the technical field of low-density cement stone strength-enhancing additives for oil and gas well cementing in the petroleum industry, and in particular relates to a composite low-density cement early-strength agent, its preparation method and application. Background technique [0002] The pace of oilfield exploration continues to increase, and with the increasing number of complex wells, long-sealed wells and wells that are prone to leakage, the density of conventional cement slurry systems is too high to meet the cementing requirements. The development and application of low-density cement is of great significance to protect oil and gas layers and improve cementing quality. Practice has proved that this technology can effectively protect oil and gas reservoirs, increase single well productivity, and has significant advantages in solving complex cementing problems such as low pressure layers, easy leakage layers, and long seal...

AI Technical Summary

Problems solved by technology

[0003] However, the inherent defects of the existing low-density cement limit its further development. With the addition of a large amount of lightening materials, the uniformity of the cement slurry will be reduced, and the process of the hydration reaction will be affected, resulting in poor performance of the slurry, especially cement stone. The strength is greatly reduced, and sometimes it is difficult to meet the requirements of sealing the formation, and the lower the density of the cement slurry, the more prominent the contradiction. Therefore, it is the current low-density cement system to seek a balance between "low density" and "high strength". important direction of development

[0004] At present, the commonly used low-density cement early strength agents are mainly inorganic salt early strength agents, including chloride salts and sulfates. Since the existence of traditional early strength agents has a corrosive effect on casing and cement stone, a chlorine-free Ionic low density cement early strength agent is very necessary

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