水溶性聚合物凝胶不成比例降低相渗透率机理研究

The mechanism study of disproportionate permeability reduction by water-soluble polymer gel

良好的选择封堵性能已成为评价堵剂的关键指标之一。为获知堵剂选择封堵现象的主导机理,设计了系列针对性流动实验,对油水通道分流、凝胶脱水和吸附滞留3个理论进行了分析。结果表明,在原油粘度较低的条件下,油水通道分流理论不是选择封堵现象的主要机理;实验中未发现脱水现象;吸附滞留是选择封堵现象产生的主要机理。另外,后续水驱流速对选择封堵现象也有一定的影响,在0.8MPa恒压下水相和油相产出量之比为2.75:100,而在1.6MPa下则为9:100,流速越大,该现象越不明显,且流速的影响不能恢复,从而也证明了油流和水流通道中吸附程度的差异是选择封堵现象的主导原因。

Excellent selective blocking property is one of the key factors for the water shutoff agent.In order to know the dominant mechanism of disproportionate permeability reduction phenomenon,a series of flow experiment are implemented to analyze three theories included the segregated oil and water pathways theory,the dehydration of gel theory and the adsorption theory.It indicates that the segregated oil and water pathways theory is not the main mechanism of DPR in low-viscosity oil condition.And,not any dehydration is observed in the test process.The adsorption theory is one of the main DPR mechanism.In addition,the subsequent water-flood velocity has an effect on the DPR.Under the condition of constant pressure injection at 0.8MPa,the producing rate of water and oil phase was 2.75:100,while 9.0:100 at 1.6MPa.DPR is weak with increased velocity,and it is not recoverable.This also proved that the difference of adsorption level in the oil and water pathway is the leading factor accounting for the DPR phenomenon.