Reasonable Amounts of Silica Sand Added to Enhance the Strength Decline for Class G Oilwell Cement under High Temperature

摘要

Characteristics of development and change of compressive strength properties of Class G oilwell cement are studied under different temperature. The influence law of temperature and silica sand on compressive strength is analyzed. Critical temperatures which the strength begin to decline are 110℃ and 150℃ respectively, and reasonable amounts of silica sand which will be added to cement slurry to enhance the strength of hardening paste are determined to be 30%～40%. The nature which temperature and silica sand affects on strength properties is revealed.