闭式注水油藏自分散型耐高温高盐调驱剂

Self-dispersed Profile Control and Flooding Agent with High Temperature and Salt Resistance Using in Self-source Water Injection Reservoir

南海东部高温高盐油藏闭式注水井无地面注水流程,常规调驱剂无法在地面混配后注入地层,且由于自分散性差,难以直接注入地层。以南海东部A油田为目标,从快速自分散和耐高温高盐两个角度出发,以2-丙烯酰胺-2-甲基丙磺酸(AMPS)含量为40%的耐温耐盐聚合物为基础,辅以多酚类复合交联剂、多支链醇聚醚类分散剂等,通过反应成胶、机械研磨,制得自分散型耐高温高盐调驱剂。采用激光粒度仪、电子显微镜、动态光散射仪等,对调驱剂的粒径、微观形貌和表面电性进行了表征,评价了调驱剂的自分散性能、注入性能和剖面调整性能,并在南海东部A油田X井组进行了现场应用。结果表明,自分散型耐高温高盐调驱剂呈球形,初始粒径D50(粒径中值)为1.09~11.63μm,通过调整配方、研磨条件或加热时间可调节调驱剂的粒径。调驱剂颗粒表面呈负电,Zeta电位值为-19.30~-26.1 mV。与常规油分散型颗粒调驱剂相比,该调驱剂自分散性好,遇水后能快速均匀分散,在注入水中的自分散率为90.0%,岩心注入压力仅为油分散型颗粒调驱剂的53.13%。调驱后,高渗透岩心的分流量由92.6%降至20.5%,低渗透岩心的分流量由7.4%增至79.5%,吸水剖面明显“反转”。现场实施效果良好,调驱剂施工爬坡压力为0.5 MPa,施工后最高日增油106 m3,阶段增油8900 m3。该调驱剂满足目标油田高温高盐条件,注入性好,增油效果明显,适合闭式注水油藏调驱。

There is no surface water injection process in the high-temperature and high-salt self-source water injection reservoirs in the east of South China Sea.The conventional profile control and flooding agent can’t be directly injected into the reservoir after mixing on the ground.It is difficult to inject into the reservoir because the conventional profile control and flooding agent has poor self-dispersion.Focusing on the A oilfield in the east of South China Sea,the self-dispersed profile control and flooding agent with high temperature and salt resistance was developed by gelation reaction and mechanical grinding miller.It was composed of polyphenol crosslinking agent,multi-branched chain alcohol polyether dispersant,and temperature-resistant and salt-resistant polymer with a content of 40%AMPS.The particle size,micro-morphology and surface electrical properties of the profile control and flooding agent were studied by laser particle size analyzer,electron microscope and dynamic light scatterer.The self-dispersion performance,injection performance and profile adjustment performance were evaluated.Finally,the field application was carried out in the X well Group of A oilfield in the east of South China Sea.The results showed that the self-dispersed profile control and flooding agent was spherical.The D50 of initial particle size was 1.09—11.63μm.It could be adjusted by changing the formula,grinding conditions or heating time.The surface of this agent was negatively charged.The Zeta potential value was-19.30—-26.1 mV.Compared with the conventional oil dispersing granule agent,the self-dispersing performance of this agent was good.It could be quickly and evenly dispersed after entering water while the self-dispersed rate in injected water was 90.0%.Furthermore,the core injection pressure was only 53.13%of that of oil dispersing granule agent.After chemical treatment,the flow ratio of high permeability core decreased from 92.6%to 20.5%,while that of low permeability core increased from 7.4%to 79.5%.The water absorption profile was obviously reversed.The field test effect was good.The increasing pressure after injecting the profile control and flooding agent was 0.5 MPa.The maximum daily oil increase was 106 m3 after field test,and then the stage increasing oil was 8900 m3.The profile control and flooding agent met the high temperature and high salt condition of target oilfield.It had good injection performance and obvious increasing oil effect,which was suitable for the self-source water injection reservoir.