聚合物驱后地层残留聚合物相对分子质量和水解度变化对其再利用效果的影响

EFFCTS OF THE VARIATION OF MOLECULAR WEIGHT AND DEGREE OF HYDROLYSIS OF THE REMAINED POLYMER IN THE FORMATION ON REUTILIZATION AFTER POLYMER FLOODING

聚合物在地层渗流过程中相对分子质量和水解度发生变化,地层残留聚合物以低相对分子质量和较高水解度的形态存在。通过再利用剂与地层残留聚合物作用,以残余阻力系数作为指标来评价地层残留聚合物相对分子质量和水解度变化对其再利用效果的影响。研究结果表明,即使聚合物相对分子质量降低,水解度升高或者两者同时变化,残余阻力系数均减小,但减小幅度不大,且仍比单纯聚合物溶液存在时的残余阻力系数大。这说明了相对分子质量降低和水解度的地层残留聚合物仍可以再利用,与再利用剂形成不同强度冻胶,封堵高渗透层,达到深部调剖作用。可视化试验结果也证明了此观点。

The molecular weight and degree of hydrolysis of the polymer are varied in the flow event, the polymer remained in the formation exists in the forms of low molecular weight and high degree of hydrolysis. Using residual resistance factor from the action between remained polymer and reutilized agent, evaluated the reutilization effects on variations of molecular and degree of hydrolysis of remained polymer in the formation. The study results show that although the molecular weight dropping, the degree of hydrolysis rising or both of them varying, but the residual resistance factor decreases a little and is also bigger than that of acting only by polymer. This clarified that the remained polymer in the formation still can be reutilized, different strength of gel can be produced by interaction between the remained polymer and reutilized agent, and block off high permeability stratum to achieve the goal of deep profile control. The visualization experiment also proves the viewpoint above.