Fumed silica A-200 (or similar grades like Aerosil® 200) is widely used to enhance the performance of oilwell cement slurries under challenging downhole conditions. Below are specific application examples demonstrating its role in optimizing slurry properties:

1. High-Temperature Stabilization for Thermal Recovery Wells
Scenario: Cementing heavy oil thermal recovery wells (e.g., SAGD wells) with exposure to steam injection temperatures up to 345°C.
Problem: Conventional cement slurries experience strength retrogression and loss of mechanical integrity under prolonged high-temperature steam cycling.
Solution:
Add fumed silica A-200K (3–5% by weight of cement, BWOC) blended with silica flour (30–35% BWOC) and dead-burned magnesia (2–3% BWOC).
Fumed silica adsorbs free water, forms a stable colloidal network, and promotes the formation of high-strength tobermorite/xonotlite crystals during hydration.
Result:
Cement slurry maintains stable rheology (plastic viscosity <100 cP) at temperatures >300°C.
Compressive strength remains >35 MPa after 98 days of steam cycling (vs. <15 MPa for untreated slurry).
Prevents micro-annuli and gas migration through improved slurry homogeneity.
话题标签#fumed silica#silica fumed#silicon dioxide 话题标签#white carbon black 话题标签#pyrogenic silica# Synthetic Amorphous Silica#nanoscale fumed silica 话题标签#Email:rhea@sdyingrui.cn; michael@sdyingrui.cn#Whatsapp: +8613583505605;+8615154536501#https://lnkd.in/e4Kd-suw