川深1井固井水泥浆高温沉降稳定性研究与应用

川深1井是一口超深风险探井，完钻井深高达8420 m，井底温度178℃，为保证固井质量，水泥浆高温沉降稳定性至关重要。论文结合水泥浆在井底的顶替和静止自由沉降过程，利用高温高压稠化停机实验结合浆杯底部沉降颗粒层的厚度，建立了水泥浆高温沉降稳定性测试评价方法。基于水泥浆高温沉降失稳机理分析，从液相和固相角度出发，基于红外光谱检测分析提出了有机聚合物液相外加剂耐温能力评价技术，结合环境扫描电镜微观结构观察探明了硅砂粗细搭配以及超细材料微硅、液硅、纳米SiO₂以及胶乳对水泥浆高温沉降稳定性的影响及其作用机理。论文研究满足了1.90～2.30g/cm3水泥浆高温150～180℃沉降稳定性的要求，研究措施应用于川深1井五开油层尾管水泥浆体系设计中，水泥浆高温沉降稳定性良好，固井质量优良率88.1%。 

Study and Application of High Temperature Settling Stability of Cementing Slurry Used in Cementing Well Chuanshen-1

The well Chuanshen-1 is an ultra-deep exploratory well with completion depth of 8,420 m and bottom hole temperature of 178℃. The high temperature settling stability of the cement slurry is critical to the success of the cementing job. In laboratory experiment, the high temperature settling stability of a cement slurry was evaluated through HTHP thickening shutdown and measuring of the thickness of the settled particles on the bottom of the cement slurry cup. A technology of evaluating the high temperature stability of liquid organic polymer additive was developed using IR spectroscopy analysis and high temperature stability analysis of cement slurry. Using environmental scanning electron microscopy, the microstructure of cement slurry was studied, and the sizing of silica sands as well as the effects and mechanisms of ultra-fine micro sand, liquid silicon, nanophase SiO2 and latex on the high temperature stability of cement slurry was investigated. The settling of cement slurries with densities between 1.90 g/cm3 and 2.30 g/cm3 at 150℃- 180℃ can be controlled using the technology studied. The technology has been applied in designing the cement slurry for cementing the 5th interval tubing string of the well Chuanshen-1. The high temperature stability of the cement slurry was excellent and the rate of excellence of the cement job was 88.1%.