KY-2型高密度压井液助剂的研制与应用

Additive KY-2 for High Density Well Control Fluids

高密度压井液助剂KY 2是一种阳离子型聚电解质 ,由脂肪胺、甲醛、二甲胺、盐酸等在催化剂作用下合成 ,可与各种高密度压井液基液 (密度 1.10～ 1.5 0 g/cm3 的卤水、CaCl2 水溶液和CaCl2 +ZnCl2 水溶液 )配伍。在密度 1.40 g/cm3 的CaCl2 水溶液中加入 30 g/LKY 2 ,在 2 5～ 95℃的不同温度下测定了所配压井液的漏斗粘度、常压和中压滤失量、表面张力 ,岩心伤害后恢复率及常温抗剪切性 ,均符合要求。该压井液滤失量较低 ;耐温性和抗剪切性好 ;岩心被伤害后的渗透率恢复率随温度升高而增大 ,2 5℃时为 99.2 % ,95 %时为 10 5 % ;表面张力随温度升高而降低 ,这有利于压井液的返排。 1993年以来在辽河、大港、胜利等油井使用加入KY 2的压井液进行修井作业超过 10 0 0井次 ,压井作业均一次成功 ,压井液返排迅速 ,修井作业成功率 10 0 %。

Additive KY-2 for high density well control fluids is a cationic polyelectrolyte prepared from aliphatic amine, formaldehyde, dimethylamine, hydrochloric acid, and catalyst and is compatible with various base fluids of density 1.10-1.50 g/cm 3 such as brines, CaCl 2 and CaCl 2+ZnCl 2 aqueous solutions. The well control fluid comprising CaCl 2 solution of 1.40 g/cm 3 and 3% KY-2 is evaluated in laboratory for funnel viscosity, filtration losses at normal and medium pressures, surface tension, permeability recovery of damaged cores after 24 hrs ageing at 25-95℃, and shear resistance. It is shown that this fluid has low filtration losses and is temperature and shear resistant; the permeability recovery rate of the cores damaged by the fluid increases with increasing temperature, being 99.2% at 25℃ and 105% at 95℃; the surface tension of the fluid decreases with increasing temperature, which is advantageous to fluid backflow. Since 1993, the well control fluids treated by KY-2 have been used in workover treatments at Liaohe, Dagang and Shengli more than 1 000 well-times and all well control jobs are fulfilled at one stroke, the fluids flow back quickly and all the workover treatments are completed successfully.