影响油井水泥浆流变性的因素

油井水泥浆的流变性是注水泥施工的一个重要工艺参数,是水泥浆配方设计的核心以及安全施工的前提。分别从油井水泥浆组成成分(石膏加量、比表面积、分散剂)、工作环境(温度、压力)、施工参数(搅拌速度、搅拌时间)和水泥浆的水灰比等方面通过试验来研究影响水泥浆流变性的因素。研究结果表明:随石膏掺量的增多,水泥颗粒的比表面积增加,水泥浆的流动性能随之变差,而比表面积为320~350 m2/kg时,水泥浆流变性能变化不大;提高搅拌速度和增长搅拌时间能提高水泥浆流变性能;随温度的升高水泥浆的流变性表现为先提高后变差的变化趋势,该试验条件下当温度高于70℃时水泥浆的流变性能明显变差,但压力对于水泥浆流变性影响不大。

STUDY ON THE INFLUENTIAL FACTOR ON CEMENT SLURRY'S RHEOLOGY

The rheology of cement slurry is an important process parameter during the cementing operation of cement engineering,and decides the state of cement slurry in annular space.So it is the key point of cement slurry's compound design and the precondition of safe operation.The effect of composition on rheology of cement slurry was studied in this paper,based on experiments presented,including slurry composition(gypsum,surface to per unit volume, additives),working environments(temperature,pressure),operation parameter(stirring time,stirring rate) and slurry parameter(water cement ratio).The result of experiments indicates that: when any of the gypsum addition and the surface to per unit volume increases,the flow property of cement slurry come to be bad totally,and it will change a little when the surface to per unit varies between 320 and 350 m~2/kg.Cement slurry's rheology can be enhanced through increasing the stirring rate and extending the stirring time.Temperature has obvious influence on the rheology of cement slurry while pressure has little influence on it.