凝析气藏解除反凝析污染、提高气井产能方法

针对凝析气藏特别是低渗透凝析气藏在开发过程中,地层压力降低到露点压力以后,凝析油会析出到地层中,造成反凝析污染,使气井产能下降;有时有水锁效应,产能将进一步降低,从而对凝析油、气采收率等产生严重影响的问题,在调研了国内外文献的基础上,探索了注甲醇段塞 N2(干气)吞吐解除反凝析、反渗吸污染,恢复气井产能方法,并设计了甲醇-地层水-凝析油气三相体系PVT相态测试方法和注甲醇段塞 N2(干气)吞吐解除反凝析、反渗吸实验测试及评价方法,该方法在现场得到了成功应用.因此研究解除凝析气藏近井地层反凝析、反渗吸地层伤害,提高气井产能的技术方法,具有重要的实际意义.

The Method Solving Condensate Block and Improving Productivity of Gas Condensate Reservoir

During the exploitation of gas condensate reservoir, especially the low permeability reservoir, the condensate oil will come out when the pressure drops down to the dew-point pressure, which will cause condensate block and decreases the well productivity, the situation will be worse if the water block exist. So there is significant value to solve these two problems. After investigating domestic and aboard literatures, authors of the paper designe a method of injecting methanol plug +N2(dry gas) puff & huff to decrease the condensate and water block to improve the well productivity. A new methanol/formation water/condensate gas system PVT phase behavior test is also carried out and injecting methanol plug +N2(dry gas) puff & huff experiment conducted, and the method is effectively applied to oil field.