四步法高压增注新技术应用研究

Applications of an Enhancing Injection Technique Called Four-step Method

针对苏北台兴油田注水压力高、地层吸水能力低的问题,结合台兴油田注水开发特征,提出了"高压增注压力稍高于储层破裂压力但不压破盖层"的方法.研究出"四步法"高压增注的工艺程序,即"吸水量预测、井底流压计算、破裂压力研究、增注压力界限确定"。在掌握了注水压力、井底压力与注水量的关系以及储层破裂压力后,进行现场高压试注试验,以确定具体的注水压力和注水量。该技术在台兴油田的现场应用后取得了较好效果,采油速度达到2.2％,有效扼制了产量快速下降趋势,实现了油田稳产高产。

Regarding the high water injection pressure and low water absorbing ability, considering the production features by water injection in the Taixing Block, this paper presents an injection method that employ an injection pressure slight higher than formation fracture pressure but not fracture formation. The method is implemented in terms of four steps, including predicting water absorptions, calculating bottom hole flow pressure, analyzing fracture pressure, figuring out enhancing injection pressure. After mastering water injection pressure, relations between water injection rate and the bottom hole pressure, and reservoir fracture pressure, test injection is carried out on wellsite to establish specific injection pressure and injection rate. This technique achieves better results in the Taixing block with a production rate up to 2.2%, retards remarkably the rapid yield-decreasing trend, and then succeeds in maintaining high yield.