High-temperature-resistant well cementation cement paste system

Abstract

The invention discloses a high-temperature-resistant well cementation cement paste system, and relates to the technical field of cement paste systems. The system comprises the following components: 60-75% of Portland cement; 15-25% of a strength recession resisting agent; 2-8% of a crystal form stabilizer; 0.5%-6% of a high-temperature retarder; and 3-8% of a high-temperature fluid loss agent, wherein the Portland cement is one of D-grade oil well cement or low-heat cement, and the specific surface area of the Portland cement is 280-350 m<2> / kg; the SiO2 content in the strength recession resisting agent is greater than 90%, and the mesh number is greater than or equal to 150 meshes; the content of SiO2 in the crystal form stabilizer is greater than 30%, and the mesh number is greater thanor equal to 600 meshes. The crystal form stabilizer is added and participates in hydration reaction when cement is hydrated, metal ions enter the structure of hydrated calcium silicate, so that conversion of tobermorite in a hydration product into xonotlite is prevented, the set cement is kept in a compact structure, and therefore, good high-temperature stability is achieved.

Description

Technical field [0001] The invention relates to the technical field of cement slurry systems, and more specifically to a high-temperature cement slurry system. Background technique [0002] With the development of deep-seated oil and gas resources in my country, the number of deep wells and ultra-deep wells is increasing year by year. Due to the geological structure, the temperature in the well increases as the depth of the well increases. In some western areas, the static temperature in the well has reached 230°C. The high temperature environment has put forward severe adjustments to drilling and completion projects, and the development of a new type of high temperature cementing slurry system is of great significance to the development of deep oil and gas resources in my country. [0003] At present, high-temperature cementing cement faces many problems. Most high-temperature retarders are prone to failure when the temperature is higher than 170℃, and it is difficult to control...

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Problems solved by technology

[0006] In order to overcome the defects and deficiencies in the above-mentioned prior art, the present invention provides a high temperature resistant cementing cement slurry system. The hydration product of cement changes from tobermorite to xonotlite. In this application, by adding a crystal form stabilizer, it participates in the hydration reaction when the cement is hydrated, and metal ions enter the structure of calcium silicate hydrate , to prevent the transformation of tobermorite to xonotlite in the hydration product, so that the cement stone maintains a compact structure, thus having good high temperature stability

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