Air Foam Flooding Technology

 1、The main mechanism of foam flooding

（1）The foam has the performance of "oil and water dissipation and stability".；

（2）Foam has the function of "plugging the water and not blocking the oil and blocking the small".

（3）The foaming agent itself is a very active anionic surfactant. It has the effect of changing the wettability of rock surface and reducing the interfacial tension

2、Technical Feature：

The project belongs to the technology of improving recovery of oil and gas well development。

（1）Air foam flooding technology combined with gas injection, active water and foam flooding, which is cheaper than nitrogen foam and active water.。

（2）The well should working during the operation

（3）It can also be used for foam flooding or foaming。

（4）The existing equipment and facilities in the oilfield can be used for the preparation and injection of foam liquid, and the site construction is simple

3、Research and application of limestone fractured reservoir

Baise oil field in 1996-2005 method on limestone fractured reservoir was carried out by air foam flooding enhance oil recovery test, carried out the foam with square, gas liquid ratio, the - air slug test optimization of ratio, injection rate; Determine the construction sequence of each injection well and reasonable injection cycle; For the safety of the air injection theory and field demonstration, research results show that in the late stage of oilfield development, air output on oxygen content in gas can be controlled in the range of security. As for 2005-2005 limestone reservoir energy, improve the oil recovery technology continues to mature application.

 Air foam flooding technology in Baise oilfield method test on limestone fractured reservoir has experienced the air foam flooding, air - bubble slug drive and auxiliary air foam flooding three stages. By the end of 2005 on 4 pieces of 6 cumulative foam injection Bai 35 Wells, injection foam liquid 3.57 x 104 m3, cumulative air injection 1000.84 x 104 m3, increased 1.596 x 104 t oil, has obtained the good water reducing effect of oil increase, the input-output ratio of 1:62.The technology is limestone fracture reservoir can supplement the Baise oilfield.  

（1）Comprehensive water cut：Drop by 5-30 percentage points

（2）Increase recoverable reserves：9.55×104t, enhanced oil recovery：5.65%。

（3）Unit foam oil increase：0.447t/m3。

（4）Cumulative oil gain：1.596×104t。

（5）Input-output ratio：1：3.62。

（6）Monitoring and analysis of oxygen content in casing gas：〈2.5%。

 4、The application of sandstone reservoir in Baise oilfield is applied

The Baise basin Ziyan oilfield, 16 block sandstone reservoir has entered the late for determining development, water drive less residual recoverable reserves, water flooding development effect is poor, in order to improve the block effect of recovery and development, draw lessons from Baise oilfield limestone fractured reservoir on the successful experience of air foam flooding, conducted in 2004 bubble auxiliary aerated water flooding pilot test. Experimental results show that the formation temperature of 49.5 ℃ low temperature light oil reservoir, the injected air and residual oil formation can occur LTO (LTO) reaction, oxygen content in gas output is lower than 2.6%, not present gas channeling phenomenon; In response to the rise in oil production and water cut, the final recovery rate is expected to increase by about 10%, and the input output ratio is greater than 1:3.2. The success of this experiment has important guiding significance for the late stage of water flooding in sandstone reservoir.