单轴应力条件下水泥石强度与弹性模量的关系

利用高温高压养护釜、压力试验机等设备对油井水泥石的应力-应变曲线进行了检测.分析了温度、外加剂对水泥石强度和弹性模量的影响规律,研究了强度与弹性模量关系模型的建立问题.结果表明,单轴应力条件下水泥石具有明显的弹性变形及脆性破坏特征;强度与弹性模最初随养护温度提升而增大,达到一定温度后,随温度继续升高而减小;各体系的强度及弹性模量均随养护时间的增长而增加,分散剂、降失水剂、胶乳能降低强度和弹性模量,早强剂、膨胀剂能增加强度和弹性模量,硅砂能增加高温条件下水泥石的强度及弹性模量;采用数据回归分析方法建立水泥石强度与弹性模量之间的关系模型,可以依据所建立的模型利用水泥石强度测试数据估算弹性模量.

Relationship between Compressive Strength and Elasticity Modulus of Cement Stone under Monopodium Stress

Using high temperature-high pressure maintenance vessels and compression testing equipment etc., stress-strain curves of oilwell cement systems were tested. Influent law of temperature and additives on the compressive strength and elasticity modulus of oilwell cement stone were analyzed. The problem for establishing relationship model between strength and elasticity modulus were researched. The following conclusions are obtained: There are sensible elastic deformation and brittle failure feature in the oilwell cement under monopodium stress conditions. At the beginning, the compressive strength and elasticity modulus of cement stones increase with the increase of temperature. After the temperature after rises a certain value, the compressive strength and elasticity modulus reduce when the temperature continue to be increased. Compressive strength and elasticity modulus of every slurries increase with the increase of curing time. Dispersing agent, filtrate reducer and latex can decline compressive strength and elasticity modulus of the cement stone, but high early agent , expanding agent can upgrade them. Silica sand can also upgrade them at high temperatures. The relationship model between strength and elasticity modulus can be established by using adopting data regression analysis method. Using tested compressive strength, the model established in this paper can be used to estimate cement elasticity modulus of cement stone.