QY气井压井液的研制与应用

Prepatation and Uses of Load Fluid QY for Gas Well Control

针对长春气田储层的水敏、碱敏、盐敏性 ,研制了由盐水基液、聚合物粘土稳定剂QYP、增粘剂QYJ、表面活性剂QYB、缓蚀剂QYH组成的气井压井液QY ,以代替现用的主要由水和粘土稳定剂 85 1组成的压井液 85 1。粘土稳定剂加量为 0 .5时 ,2口气井岩心样在压井液QY、压井液 85 1和清水中的膨胀率分别为 13.3%和 3.3% ,2 1.5 %和 7.7% ,5 0 .0 %和 36 .7%。表面活性剂加量为 0 .5 %的压井液QY和压井液 85 1的表面张力分别为 36 .3和 4 7.9mN/m ,界面张力分别为 2 .1和 6 .7mN/m。增粘剂加量为 0 .5 %的压井液QY的初滤失量为 0 .791mL ,36min滤失量为 4 .8mL ,粘度 4 2mPa·s。压井液QY 4 5℃时腐蚀速率较小 ,为 0 .0 73g/m2 ·h ,pH值为 7～ 8。与压井液 85 1相比 ,压井液QY对气测渗透率 2 .71× 10 -3 ～ 139.7× 10 -3 μm2 的 4支岩心的伤害率由 2 4 .7%～ 6 0 .2 % ,平均39.9%降至 14 .6 %～ 19.2 % ,平均 16 .7%。气井压井液QY在长春气田 3口井施工中应用 ,效果良好。图 1表 4参 1。

A load fluid, QY, for gas well control is prepared with water , alkaline and salt sensitivities of Changchun gas reservoirs being considered and is composed of salts water as base fluid, polymeric clay stabilizer QYP, viscosifier QYJ, surfactant QYB and corrosion inhibitor QYB to replace presently used load fluid 851, which consists mainly of water and clay stabilizer 851. The swelling rate of 2 reservoir core samples in load fluids QY and 851 with 0.5% clay stabilizer added and in fresh water accounts 13.3% and 3.3% , 21.5% and 7.7%, and 50.0% and 36.7%, respectively. The surface tension of load fluid QY with 0.5% surfactant added and load fluid 851 is of 36.3 and 47.9 mN/m and the interfacial tension-2.1 and 6.7 mN/m, respectively. The filtrate loss of load fluid QY with 0.5% viscosifier added at starting and in 36 min is of 0.791 and 4.8 mL. Load fluid QY has viscosity 42 mPa·s, corrosion rate at 45℃ 0.073 g/m 3·h and pH value 7-8. The damage caused by load fluid QY for 4 reservoir core samples of gas permeability 2.71×10 -3 -139.7×10 -3 μm 2 is in range 14.6-19.2% and of 16.7% in average comparing with 24.7-60.2% and 39.9% in average in the case of load fluid 851. The uses of load fluid QY on 3 gas wells in Changchun gas fields are successful.