低成本平衡压井液性能评价及关键影响因素研究

Research on Performance Evaluation and Key Influencing Factors of Low Cost Balanced Well Killing Fluid

摘要: 为满足油气田低成本、高性能压井作业需求，以低成本平衡压井液为对象，系统开展了岩心渗透率与滤失量性能评价，并考察密度、温度、膨润土类型及稠化剂种类等关键因素的影响。结果表明，该压井液岩心渗透率损害率仅1.56%~14.73%，滤失量7.0~51.0 mL，综合性能良好，且较常规锌盐加重体系具有显著的成本优势。密度升高加剧渗透率损害，温度对滤失呈非线性调控作用。优选配方动塑比最高达1.61，密度可调范围1.5~1.7 g/cm³，具备良好剪切稀释性、悬浮稳定性和储层保护能力。本研究为低成本平衡压井液配方优化与现场应用提供了实验依据。

Abstract: To satisfy the demands of low-cost and high-performance well killing operations in oil and gas fields, a low-cost balanced well killing fluid was taken as the research subject. Systematic performance evaluations including core permeability and fluid loss were carried out, and the influences of key factors such as fluid density, temperature, bentonite type and thickener category were investigated. The experimental results reveal that the core permeability damage rate of the well killing fluid ranges from 1.56% to 14.73%, with fluid loss controlled between 7.0 mL and 51.0 mL, demonstrating good comprehensive performance with a significant cost advantage over conventional zinc-salt weighted systems. Increasing fluid density aggravates core permeability damage, while temperature exerts a nonlinear regulating effect on fluid loss. The optimized formulation achieves a maximum dynamic-plastic viscosity ratio of 1.61 with an adjustable density range of 1.5~1.7 g/cm³, and exhibits favorable shear thinning property, suspension stability and reservoir protection capacity. This study provides experimental support for formula optimization and field application of low-cost balanced well killing fluids.