Nitrogen foam profile control technology

1、Technology Introduction

For steam channeling and overlapping of heavy oil thermal recovery, the injection nitrogen foam is used to adjust the steam injection profile. Foam can effectively reduce the seepage capacity of steam in large channels, improve  sweep efficiency, force following-injected steam turn to not-flooding area, increases the flooding area and conformance efficiency. Meanwhile, as a surfactant, foam can greatly reduce oil and water interfacial tension, improve the wettability of rock surface and improve oil displacement efficiency.

2、Technical application case

90 wells of “Cao 20 block” implement profile control, average periodic output increased from 409t to 612t, compared with the same period natural decline decreases from 36% to 15%. In 2002, expansion implementation in “Cao 20 block”, 28 wells, oil production increased 1.07 10700t. The production of block production is not decreasing.

The effect of nitrogen foam profile control is remarkable, but only in one period, the validity period is shorter, which does not change the nature of the high channel. But this is only in one cycle, the validity period is shorter, which does not change the nature of the high pore. With the increase of the throughput rounds, more foams are required to achieve the same effect.