塔河气田纳米颗粒活性油堵水剂实验

Experiment on Nanoparticle Active Oil Water Plugging Agent in Tahe Gas Field

塔河气田前期采用冻胶堵水方法,对直井效果显著,但对水平井无法达到长期控水要求。针对水平井堵水特点,研制了一种纳米颗粒活性油堵水剂,堵水剂由纳米颗粒、乳化剂咪唑啉和柴油组成。该堵水剂易于注入,受地层水微剪切力,可生成油包水乳状液,在高温和纳米颗粒的作用下黏度增大。乳状液主要通过贾敏效应控制地层水进入高渗通道,从而降低产水率。在低渗产气通道内,主要是体系中的纳米颗粒通过改变储集层润湿性,解除通道水锁。乳状液会被凝析油稀释,因此不会造成气道堵塞。实验室评价表明,该体系具有很好的选择性控水能力,最大残余阻力系数为27,耐冲刷性强,可降低气井产水率并恢复产气量。

The gel was used in Tahe gas field to plug water in the early production stage and a significant effect was obtained in vertical wells,but it could not meet long⁃term water control requirements for horizontal wells.Aiming at the water plugging characteristics in hori⁃zontal wells,a nanoparticle active⁃oil water plugging agent was developed,which was composed of nanoparticles,emulsifier imidazoline and diesel.The water plugging agent is easy to be injected,and can form a kind of water⁃in⁃oil emulsion due to micro shear force of the for⁃mation water.The viscosity of the water⁃in⁃oil emulsion will increase under the action of high temperature and nanoparticles.The Jamin ef⁃fect of the emulsion prevents the formation water from entering highly permeable channels,thereby reducing the water production rate.In the low⁃permeability channels,the nanoparticles in the system change the wettability of the reservoir to release the water lock of the chan⁃nels.The emulsion will be diluted by condensate oil,so it will not block the gas channels.Laboratory evaluations show that the system has good selective water control capabilities with strong erosion resistance and a maximum residual resistance coefficient of 27,which can re⁃duce the water production rate and restore gas production in gas wells.