Bin 660 Block Active Agent Increase Test Pilot Injection

The low permeability reservoirs have been becoming an important part of petroleum resources in Shengli Oilfield. Most of the low permeability oilfields in Shengli oilfield are mainly water-flooded development approach. The physical properties of low permeability reservoirs are usually different from common reservoirs, and small pore, low permeability and high flow resistance are commonly found in low permeability reservoirs. In addition, there are sensitive minerals are in the reservoir and the injection water is not compatible with the formation water. These factors cause great damage to the formation. The injection pressure is increasing and the injection rate is reducing. Furthermore, the potential of the common fracturing and acidizing are low and the effective time is short. Surfactant associated with water injection to deal with larger radius, surfactant flooding in high permeability reservoirs has achieved good results. So the study of surfactant flooding in lowering injection pressure is significant to the development of low permeability reservoirs. In this paper, laboratory experiments as a means of water flooding characteristics in low permeability reservoir were conducted. The interfacial tension is the main evaluation index of the surfactant used for reducing injecting pressure. The concentrations of surfactant, salinity and pH on interfacial tension behaviors were investigated. In this paper, We carried out chemical flooding to reduce injecting pressure and evaluated the influence of surfactant flooding in low permeability reservoirs. Also, the surfactant slug size, injection rate and injection opportunity on reducing injecting pressure were investigated. Research indicates that surfactant flooding could reduce the injection pressure of low-permeability permeability, improve the two phase flow characteristics, increase the relative permeability of both phases, widen two phase flow region Detection results exhibit that with the increase of the surfactant slug size, the lowering injection pressure effectiveness rises, which decreases with the injection rate.