对内部注水小断块油藏提高采收率的认识

对江苏油田内部注水油藏（主要指切割注水及封闭断块注水）在开发中出现的见水早、含水上升快、水驱波及系数及采收率低等问题地进行了分析，指出单层突进及粘性指进是造成这一现象的根本原因。分析了影响单层突进及粘性指进的因素，提出了控制单层突进及粘性指进的措施及提高水驱波及系数和采收率的方法，如：先期分注；常规井距下注采比控制在0.8以内等方法。认为内部注水油藏适当放大注采井距不仅可以节约投资，而且有益于控制单层突进及粘性指进并提高采收率。

Knowledge of EOR by internal water-injection in small block reservoir

It is analyzed to early water breakthrough, rapid raise of water cut, low swept volume for waterflooding and low recovery factor appeared in the production of internal water?injection reservoir (mainly refers to cutting water injection and water injection for closed block) in Jiangsu oil field. It is pointed out that monolayer breakthrough and viscous fingering are considered as basic reasons for the occurrence. The influence factors for them are analyzed. The measures for controlling them and for improving sweep efficiency and enhancing oil recovery are proposed, such as initial separate injection, injection?production ratio less than 0.8 at regular producer?injector spacing and so on. Enlarging well space properly in internal water?injection reservoirs is considered not only to save the investment, but also to control monolayer breakthrough, viscous fingering and to enhance oil recovery.