Aiming to resolve the problem that the down-hole environments (HTHP and restrained) can-imnot be simulated by the popularly used methods,and the measurements of laboratory experiment are im-practical, a testing device, named measuring instrument for evaluating volume stability of HTHP cement slurry,was developed. The instrument can simulate the down-hole environment and measure the expansion rate of cement slurry continuously when it is in plastic state and hardening state. The process of experiment is recorded and the curves of temperature-time,pressure-time and height increment-time are drawn by data acquisition and management software. There are two measuring sensors which can complete a comparison test and the results are compared with the test detected by spiral micrometer and measuring cylinder. It was shown that data derived from this device was smaller and more reliable than spiral micrometer used to de-tect the cement slurry with crystalloid expanding agent. Volume stability of the cement slurry with gas for-mer, which can not be evaluated by normal methods,can also be appraised by this instrument. The experi-ment showed that the device could be used for evaluating volume stability,oil cement additive optimization and formulation designing. However, the graphical interface of data acquisition and management software should be simplified because it was not concise.%针对常用测试方法不能真实模拟井下高温高压受限环境、室内测试结果失真的问题,研制了高温高压水泥浆体积稳定性测定仪.该仪器能模拟井下高温高压条件,可连续测量水泥浆在塑性状态和硬化状态下的膨胀率,数据采集管理软件可记录整个试验过程,并能生成温度、压力、水泥浆高度增量随时间的变化曲线.该仪器有两套测试筒,可进行对比试验.与螺旋测微仪、量筒进行了对比试验,结果表明:对于晶体类膨胀剂,高温高压水泥浆体积稳定性测定仪的测量结果比螺旋测微仪小,数据更真实；对于常规仪器无法评价的发气类膨胀剂,该仪器也能客观评价.试验表明,高温高压水泥浆体积稳定性测定仪可用于评价固井水泥浆的体积稳定性、优选油井水泥膨胀剂和进行水泥浆配方设计,但数据采集管理软件界面不够简洁,需进一步优化.
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