Endogenous toughened corrosion-resistant cement mortar system

Abstract

The invention discloses an endogenous toughened corrosion-resistant cement mortar system which is composed of the following components in parts by weight: 100 parts of high-sulfate-resistance Grade-G oil well cement, 5-35 parts of microcrystal calcium aluminoferrite, 0-25 parts of micro silicon, 1.0-4.5 parts of water-loss control agent, 0.5-3.0 parts of dispersing agent, 0.2-3.0 parts of thickening time control agent and 44-80 parts of water. The microcrystal calcium aluminoferrite is prepared by high-temperature calcination and shock cooling. The micro silicon is a density regulator. The water-loss control agent is polyvinyl alcohol, polyacrylamide or carboxymethyl cellulose. The dispersing agent is sodium hexametaphosphate, melamine formaldehyde resin, sodium lignosulfonate or methyl cellulose. The thickening time control agent is boric acid, gypsum, sodium borate or a mixture thereof. The endogenous toughened corrosion-resistant cement mortar system has the advantages of excellent impact resistance, higher compression strength, high volume stability and small changes of porosity and permeability, has important meanings for ensuring safe and efficient development of shale gas, and thus, has broad market prospects.

Description

technical field [0001] The invention relates to an endogenous toughened and corrosion-resistant cement slurry system, which is particularly suitable for well cementing operations requiring strict toughness and corrosion resistance of cement stones such as shale gas wells, ultra-deep wells and acid oil and gas wells. Background technique [0002] With the proposal of the National Thirteenth Five-Year Oil and Gas Strategic Plan, natural gas resources have become one of the important forms of energy for my country's national economic and social development, featuring high efficiency, environmental protection, and cleanliness. The world's total shale gas reserves are equivalent to the total reserves of conventional natural gas resources, and China's recoverable shale gas resources rank first in the world (about 36 trillion cubic meters, accounting for 20% of the world's total recoverable resources). If shale gas resources are efficiently and rationally utilized, it can well solv...

AI Technical Summary

Problems solved by technology

Although the toughness of cement stone can be improved by adding plasma-modified carbon fiber, the aspect ratio of carbon fiber is large, the dispersion in cement slurry is poor, and the compatibility is not good, which leads to the compressive strength of cement stone. lower

In order to overcome the shortcomings of the existing toughening cement slurry system for well cementing, such as low strength, difficulty in large-scale application, poor corrosion resistance and impact resistance, etc., efforts have been made to make breakthroughs in the field of shale gas well cementing. Endogenous toughening and corrosion resistance The research value of cement slurry system is gradually emerging

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