Composition and application of low-temperature and hydration synergistic low-heat early-strength cement slurry system

Abstract

The invention discloses composition and application of a low-temperature and hydration synergistic low-heat early-strength cement slurry system. The low-heat early-strength cement slurry system is prepared from the following components in parts by weight: 100 parts of oil well cement, 70-100 parts of a low-hydration-heat active cementing material, 3.2-6.3 parts of a hydrated calcium silicate-polycarboxylic acid ether nano composite early strength agent, 1.8-5.4 parts of a low-temperature activator, 0.7-1.3 parts of a fluid loss agent, 0.3-0.6 part of a dispersing agent, 0.2-1.0 part of a defoaming agent, 15-20 parts of hollow glass beads and 60-92 parts of water. According to the cement slurry system, on the basis that a low-hydration-heat-activity cementing material is selected, the hydrated calcium silicate-polycarboxylate ether nano-composite early strength agent and the low-temperature activating agent are adopted and have a synergistic effect, and the compressive strength of set cement in the curing period is jointly promoted; and the cement slurry system has the characteristics of being small in hydration heat release, high in early strength and the like, and meanwhile, has the advantages of adjustable density, adjustable thickening time, good rheological property, low filter loss, short setting waiting time and the like, is suitable for well cementation of ocean deepwater surface layers and hydrate layers, and lays a solid foundation for development of ocean oil and gas resources.

Description

technical field [0001] The invention relates to the technical field of oil and gas field development, in particular to a low-heat early-strength cement slurry system that is particularly suitable for low-temperature synergistic hydration of natural gas hydrates in the South China Sea. Background technique [0002] At the present stage, my country still mainly conducts exploration and development of land oil and gas resources, and seldom develops offshore oil and gas resources. It is preliminarily predicted that the natural gas hydrate resources in my country's sea area are about 80 billion tons of oil equivalent. At the same time, natural gas hydrate is a clean future energy that can effectively reduce carbon emissions. At present, my country has carried out two trial production operations of natural gas hydrate in sea areas, realizing a major leap from "exploratory trial production" to "experimental trial production". In order to realize the commercial development of natu...

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Problems solved by technology

[0010] The present invention aims at the difficult problem of cementing operation in ocean deep water surface layer and hydrate layer, on the basis of the existing cement slurry system with low hydration heat, it provides a new low-heat early-strength cement slurry system with low-temperature synergistic hydration and synergistic effect. Solve a series of problems such as excessive hydration heat release of oil well cement slurry system, long waiting time for setting, low early strength in low temperature environment, etc.

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