改性硅酮CO₂增稠剂对流体流变性和驱油效率的影响

Effect of Modified Silicone CO₂ Thickener on Fluid Rheology and Oil Displacement Efficiency

眭世元 肖朴夫 崔茂蕾

SUI Shiyuan XIAO Pufu CUI Maolei

在压裂过程中，液态CO2压裂液的压裂性能发生了很大的变化。为了改善CO2压裂效果，提高CO2对页岩 中原油的置换效率，提出合成硅酮CO2增稠剂的新思路：通过开环聚合和硅氢化反应，将亲CO2短链引入聚合物 主链分子间，形成空间网状结构。研究了CO2增稠剂对流体黏度、流变特性和驱油效率的影响。结果表明，增稠 剂加量和相对分子质量均能显著改善CO2流体的流变性，其稠度系数随增稠剂加量的增加而增大，而流变性指 数呈下降趋势。当体系压力超过12 MPa后，三维网状结构的稳定性加强，表观黏度增加。相比超临界CO2驱，增 稠CO2流体能提高0.01 μm以上孔隙中原油的动用效率，提高驱油效率12.23 百分点。研究结果为改进CO2压裂 工艺和CO2增稠剂的分子设计提供了技术参考。

During fracturing，the fracturing performance of liquid CO2 fracturing fluid has changed greatly. In order to improve the effect of CO2 fracturing and the displacement efficiency of CO2 to shale crude oil，a new idea of synthesizing silicone CO2 thickener was put forward. Through ring-opening polymerization and hydrosilylation reaction，CO2-friendly short chain was introduced into the intermolecular of polymer main chain. As a result，a spatial network structure formed. The effects of CO2 thickener on fluid viscosity，rheological properties and oil displacement efficiency were studied. The results showed that both the dosage and the relative molecular mass of thickener could significantly improve the rheology of CO2 fluid. Its consistency coefficient increased with increasing amount of thickener，while the rheological index showed a downward trend. When the system pressure exceeded 12 MPa，the stability of three-dimensional network structure was strengthened and the apparent viscosity increased. Compared with supercritical CO2 flooding，thickened CO2 fluid could improve the production efficiency of crude oil in pores above 0.01 μm. Furthermore，the oil displacement efficiency was increased by 12.23 percentage points. The research results provided technical reference for improving CO2 fracturing technology and molecular design of CO2 thickener.

10.19346/j.cnki.1000-4092.2023.02.007