A kind of composite particle, its preparation method and application

Abstract

The invention relates to the technical field of oil gas well cementing, and especially relates to a composite particle, and a preparation method and an application thereof. The composite particle comprises a core which is an elastic particle and a shell layer which is a rigid particle and coats the external surface of the core. The preparation method of the composite particle is characterized in that airflow entrainment is used to drive the elastic particle and the rigid particle to move relative to each other in order to form the composite particle. The composite particle has high temperature resistance, improves the acid and alkali resistance of the elastic particle, has good stability, has good compatibility with cement mortar, has no floatation phenomenon, has no thickness increase phenomenon in the curing process, obviously reduces the elastic modulus of set cement, increases the deformation ability of the set cement, is spherical, and facilitates increase of the fluidity of the cement mortar.

Description

technical field [0001] The invention relates to the technical field of oil and gas well cementing, in particular to a composite particle, its preparation method and application. Background technique [0002] As the gas well annulus under pressure becomes more and more common, the sealing quality and durability of the cement sheath are getting more and more attention in the industry. However, conventional cement stone is a brittle material. During the long-term production or operation of oil wells, the cement sheath is prone to cracks or micro-annulus, resulting in wellhead pressure. In particular, the current application of staged fracturing technology for shale oil and gas and tight oil and gas wells has higher requirements on the elastic deformation capacity of cement stones, and requires cement stones to be able to couple casing deformation. Therefore, in order to effectively improve the long-term sealing ability of the cement stone, it is necessary to effectively improv...

AI Technical Summary

Problems solved by technology

At present, the materials commonly used to improve the elastic properties of cement stone mainly include: styrene-butadiene latex latex, styrene-acrylic latex, rubber particles and organic resins, etc., but the high price of latex and organic resins limits their wide use. The application of granular and resin materials in oil and gas well cementing is affected due to their poor temperature resistance and their own defects.

Among them, rubber particles have become the preferred material for many elastic cement slurry systems due to their wide range of sources and low price. However, their surface is hydrophobic, easy to float and poor in temperature resistance, which has greatly restricted their application.

Images