| 摘要: |
| 针对镇北油田长8注水井注水压力高且逐年上升,欠注严重,酸化增注效果差且有效期短的问题,提出了缓速酸冲压酸化工艺。运用水力冲压产生微裂缝,再用缓速酸进行酸化。根据区块的物性和储层伤害因素的分析,优选出了缓速酸的酸液体系为8%(w)HCl+3%(w)HF+1%(w)HBF4+3%(w)HEDP+3%(w)H3PO4+1%(w)聚环氧琥珀酸钠+1%(w)聚乙二醇。该酸液体系1 h溶蚀率为25.02%,8 h溶蚀率为35.31%；Ca2+抑制率为87.76%,Mg2+抑制率为88.87%,Fe3+抑制率为86.88%,沉淀抑制性明显优于目前在用酸化体系；岩心驱替实验也表明该酸液体系能明显改善地层的渗透率。在室内研究的基础上进行现场试验3井次,平均注水压力下降了3.9 MPa,日增注51 m3,有效期已达到270天,取得了较好的降压增注效果。 |
| 关键词: 低渗透油田 注水井 水力冲压 降压增注 |
| DOI：10.3969/j.issn.1007-3426.2020.05.014 |
| 分类号: |
| 基金项目:国家自然科学基金“致密油水平井SRV与基质耦合变质量流动模型研究”(51504038) |
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| Research and application of slow acid stamping acidification and augmented injection technology in Zhenbei Chang 8 reservoir |
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Wang Yong1, Wang Erzhen1, Sui Lei1, Zhang Dingxue2, Gao Wei2
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1.National Engineering Laboratory of Low Permeability Oil and Gas Exploration and Development, Research Institute of Exploration and Development, PetroChina Changqing Oilfield Company, Shaanxi, Xi’an, China;2. College of Petroleum Engineering, Yangtze University, Wuhan, Hubei, China
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| Abstract: |
| In view of the problems such as a high pressure of water injection of Chang 8 water injection well in Zhenbei oilfield and its increasing year by year, a serious condition of under injection, poor acidizing effect and the short effective period, a slow acid stamping acidizing process is proposed. The microcracks are produced by hydraulic stamping, then acidized by retarded acid. According to the analysis of physical properties of block and damage factors of reservoir, the acid system and additive of slow acid are preferred, which is 8% HCl + 3% HF + 1% HBF4 + 3% HEDP + 3% H3PO4 + 1% polyepoxysuccinate sodium + 1% polyethylene glycol. For this acid solution system,the dissolution rates of 1 h and 8 h reach 25.02% and 35.31% respectively. The inhibition rate of precipitation of calcium ions, magnesium ions and iron ions are 87.76%, 88.87% and 86.88% respectively. The property of precipitation inhibition is obviously better than the current acidizing system. This acid system can improve significantly the permeability, which was tested by the core displacement experiment. On the basis of indoor research, field tests have been carried out for 3 times and good results have been achieved. After the measures, the water injection pressure decreased by 3.9 MPa, the daily injection increased by 51 m3/d, and the validity period had been up to 270 days. It has achieved a good effect of reducing pressure and increasing injection. |
| Key words: low permeability oil field water injection well hydraulic stamping decompression and augmented injection |
