注水水质对裂缝性油藏储层的影响

以裂缝性油藏储层为研究对象，通过室内岩心模拟实验研究了注入水悬浮物和含油量对储层的伤害。研究结果表明，悬浮物颗粒直径中值、含油量是引起储层伤害的主要因素；当渗透率伤害率上限为20%，缝宽≤50 μm时，注水水质要求为:悬浮物颗粒直径中值(粒径中值)不应超过10 μm，悬浮固体含量不应超过10 mg/L，含油量不应超过10 mg/L；当缝宽介于50~100 μm时，注水水质要求为:悬浮物粒径中值不应超过20 μm，悬浮固体含量不应超过10 mg/L，含油量不应超过20 mg/L；当缝宽介于100~200 μm时，注水水质要求为:悬浮物粒径中值不应超过50 μm，悬浮固体含量不应超过50 mg/L，含油量不应超过40 mg/L；当缝宽大于200 μm时，注水水质要求为:悬浮物粒径中值不应超过60 μm，悬浮固体含量不应超过80 mg/L，含油量不应超过50 mg/L。研究结果可为裂缝型油藏高效注水开发提供理论依据。

Effects of injected water quality on fractured oil reservoirs

This research investigated the reservoir damage of naturally fractured oil reservoirs caused by suspended solids and oil in injected water via laboratory core flooding tests. The results showed that the median diameter of suspended solid particles and oil content are the main factors controlling reservoir damage. With the permeability damage upper limit of 20%, the injected water quality requirements are that the median diameter and content of suspended solids should be no more than 10 μm and 10 mg/L respectively, and the oil content should be no more than 10 mg/L, for fracture widths ≤50 μm; the median diameter and content of suspended solids, no more than 20 μm and 10 mg/L respectively, and the oil content no more than 20 mg/L, for fracture widths of 50–100 μm; the median diameter and content of suspended solids no more than 50 μm and 50 mg/L respectively, and the oil content no more than 40 mg/L, for fracture widths of 100–200 μm; the median diameter and content of suspended solids no more than 60 μm and 80 mg/L, respectively, and the oil content no more than 50 mg/L. The findings of this research laid down the theoretical basis for high-efficiency water flooding of fractured oil reservoirs.