摘要
注入水与地层水混合后产生的盐类沉淀(特别是CaSO4)不仅会堵塞储层的孔隙、降低储层渗透率、减少油气产量,还会对注入和生产设备造成损害。文章针对油田注水工艺过程中出现的实际问题,以现场采集的岩心、地层水以及配制的不同矿化度的注入水为基础进行了岩心驱替实验,记录了不同温度、注入水体积条件下的实验数据,计算了岩心渗透率的变化情况,研究了含纳米SiO2颗粒的注入水对储层渗透率的影响规律,对比添加纳米SiO2前后岩心的渗透率计算结果。实验结果表明,纳米SiO2在减少CaSO4沉淀和保护储层方面具有积极的作用,能够有效的防止CaSO4沉淀对储层的损害。在40℃条件下,未添加纳米SiO2时1^#注入水的平均相对渗透率仅为0.261,添加纳米SiO2后上升至0.92。在25℃~40℃范围内,岩心的渗透率随温度的增加而增加;在40℃~80℃范围内,岩心的渗透率随温度的增加而呈降低的趋势。
The salt precipitation(especially CaSO4)produced by the mixture of injected water and formation water will not only block the pores of the reservoir,reduce the permeability of the reservoir,reduce the production of oil and gas,but also cause damage to the injection and production equipment.In this paper,aiming at the practical problems in the process of crude oil injection,core displacement experiments are carried out on the basis of core collected in situ,formation water and injected water with different salinity.The experimental data under different temperature and volume of injected water are recorded,the variation of core permeability is calculated,and the influence of injected water containing Nano-SiO2 particles on reservoir permeability is studied.The calculation results of core permeability are compared with and without Nano-SiO2 added.The experimental results show that Nano-SiO2 plays an active role in reducing CaSO4 precipitation and protecting reservoirs,and can effectively prevent the damage of CaSO4 precipitation to reservoirs.At 40℃,the average relative permeability of 1#injected water is only 0.261when Nano-SiO2 is not added,and increases to 0.92 after adding Nano-SiO2.In the range of 25℃~40℃,the permeability of the core increases with the increase of temperature,and in the range of 40℃~80℃,the permeability of the core decreases with the increase of temperature,injection water,permeability,core displacement,reservoir protection.
作者
荣雁
RONG Yan(Shengli Oilfield Xinchun Company,Dongying,Shandong 257000,China)
出处
《钻采工艺》
CAS
北大核心
2020年第1期98-101,I0007,共5页
Drilling & Production Technology
