防膨工艺是抑制注水井近井地带粘土膨胀的有效措施之一。针对常规的防膨剂成分单一,对注水通道改善能力有限的问题,室内实验优选出最佳复合防膨剂FP-H3。复合防膨剂FP-H3最佳使用浓度为3%,90℃下性能良好,三次水洗后的防膨率为82.0%。现场应用结果表明,复合防膨体系在注入过程中,相同排量下,注入压力降低2~3 MPa,恢复油藏正常注水后,试验井的视吸水指数得到提高且注水趋于稳定状态,复合防膨工艺有效抑制了注水井近井地带粘土的水化膨胀。 Anti-swelling process is one of the effective measures to inhibit clay expansion near water well. Aiming at the problem that the conventional anti-swelling agent has a single component and the ability to improve the water-pouring channel is limited, the best composite anti-swelling agent FP-H3 is selected in laboratory experiment. The optimum concentration of compound anti-swelling agent FP-H3 is 3%, the performance is good at 90 ℃, and the anti-swelling rate after three times of washing is 82.0%. The field application results show that the injection pressure of the composite anti-swelling system decreases by 2-3 MPa at the same displacement during the injection process and the apparent water absorption index of the test well is increased and the water injection tends to be stable after the normal injection of the reservoir is restored. The anti-swelling process effectively inhibits the hydration expansion of clay near the wellbore of a water injection well.