方法 针对胡状集－庆祖集油田具体情况，开展下４英寸套管工艺技术研究。目的解决胡状集－庆祖集油田开采中暴露的问题：一是套管腐蚀加剧，破坏了注采并网；二是油水井射孔井段长，层间矛盾突出，中低渗透层动用较差．结果截止 １９９９年底，胡收集一庆祖集油田共在 １８口井（其中水井 １２口）中实施了下 ４英寸套管措施，均获得了成功。结论该工艺可提高油田的水驱动用储量，增加可采储量，具有较好的经济效益和社会效益，是提高老油田开发水平，提高油田采收率的有效措施之一。 Methods According to the specific conditions of Huzhuji-Qingzuji Oilfield, a 4-inch casing technology research was carried out. Aim To solve the problems exposed in the Huzhuji-Qingzuji oil field exploitation, firstly, the casing corrosion is aggravated and the injection-production and grid connection are destroyed; second, Poor. Results By the end of 1999, the Hu-Qing-Qing-Zuji Oilfield had succeeded in implementing the next 4-inch casing in 18 wells (of which 12 wells). Conclusion The technology can improve the water-driven reserves of oilfields and increase the recoverable reserves, which has good economic and social benefits. It is one of the effective measures to improve the development level of old oilfields and increase oil recovery.