深井高温条件下油井水泥强度变化规律研究

Change of cement stone strength in the deep high temperature oil well

对深井高温条件下G级油井水泥石强度变化特点进行了实验研究，分析了温度、硅砂加量对G级油井水泥石强度的影响。实验表明：G级油井水泥石在高温条件下产生强度衰退，强度衰退的临界温度分别为110℃和150℃。在水泥中加入硅砂可以抑制水泥石的高温强度衰退，硅砂的合理加量为水泥量的30％-40％。由于高温下水泥中的水化产物会发生变化，因此温度对水泥石强度也产生影响。

Changing characteristics of Class G cement stone strength in the deep high temperature oil well were analyzed experimen-tally. The influence of temperature and the amount of silica sand on the strength of cement stone were discussed. The strength of cement stone begins to decline at the critical temperatures of 110℃ and 150℃, respectively. The amount of silica sand added into cement can control the decline of cement stone strength. The reasonable ratio of silica sand ranged from 30 percent to 40 percent. The strength of cement stone was also affected by temperature because of the change of hydrate in cement at high temperature.