High-temperature-resistant high-strength low-density well-cementing cement slurry

Abstract

The invention discloses high-temperature-resistant high-strength low-density well-cementing cement slurry. The high-temperature-resistant high-strength low-density well-cementing cement slurry is prepared from the following components in parts by weight: 100 parts of G-level oil well cement, 15-76 parts of a lightening admixture, 20-40 parts of micro-silicon, 2-10 parts of a fluid loss agent, 1-8 parts of a dispersing agent, 0-5 parts of a retarder, 0-1.25 parts of a coagulant, 0-5 parts of an anti-fluid-channeling agent, 0.2-0.8 part of an antifoaming agent and 50-120 parts of fresh water, wherein the G-level oil well cement is high sulfate-resistant oil well cement, the lightening admixture is high-performance hollow glass beads. According to the grain grading principle, a series of low-density well-cementing cement slurries with densities of 0.90-1.50g / m<3> are prepared. The low-density well-cementing cement slurry can be used for lowering the density of the cement slurry on the premise of guaranteeing comprehensive performances such as cement slurry strength, good high-temperature high-pressure stability and low water loss, increasing the scope of application of the low-density cement slurry in complex wells such as a deep well, an ultra-deep well and a low-pressure easy-leakage well, and improving the well-cementing quality.

Description

technical field [0001] The invention relates to a cement slurry used in the technical field of oil field drilling and cementing, which is suitable for cementing operations such as deep wells, ultra-deep wells, low-pressure leaky wells, and underbalanced wells. Background technique [0002] With the development of drilling and completion technology, more and more complex formation reservoirs such as ancient buried hill reservoirs and marine carbonate fracture reservoirs have been developed. In the development of reservoirs with complex formations, drilling and completion designs such as deep wells, ultra-deep wells, underbalanced wells, and open hole long sealing are often used. Among them, the staged cementing technology is time-consuming and prone to accidents resulting in heavy losses due to high equipment requirements , so low-density cement slurry is mainly used to prevent leakage of low-pressure formations from polluting the reservoir. Traditional low-density cement sl...

AI Technical Summary

Problems solved by technology

At present, the low-density cement slurry of hollow glass microspheres mostly uses foreign hollow glass microspheres, which are expensive, which limits their wide promotion in oil and gas field production.

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