The Research Of Foaming Enhancing The OOIP Of High Temperature And Salinity Reservoir

Based on research on synthesis of alcohol polyoxyethylene ether sulfonate, composition of temperature and salt resisting foaming agent is decided and formula of the foaming agent is optimized and decided. The relationships between dynamic parameters are studied, including viscoelastic modulus of foaming agent, dynamic interfacial tension, half life and liquid carrying factor. Influential factors on foam stability in porous media are also studied. Physical simulation of EOR with foam system under hyperthermic & hyperhaline conditions is also carried out. The extents of EOR with hyperthermic & hyperhaline foam system are researched. The following research results are acquired:1. Establishment of temperature and salt resisting foaming agent. According to principle of surfactant's increasing effect, zwitterions compounding foam agent of alcohol polyoxyethylene ether sulfonate plus CTAB plus normal butyl alcohol is developed. Overall performance evaluation of foam formula system shows that the foaming agent has preferable foaming performance under conditions of porous media, and foam drive can be carried out in hyperthermic & hyperhaline reservoirs.3. Analysis of dynamic stability of temperature and salt resisting foam system. Key factors that influence foam stability are studied by testing dynamic interfacial tension, liquid carrying factor, viscoelastic modulus and stability factor. Research results show that both viscoelastic modulus and liquid carrying factor are main factors that affect foam stability, and temperature, pressure and salinity influence foam stability by influencing viscoelastic modulus and liquid carrying factor. Liquid carrying factor is a direct ratio to stability factor and viscoelastic modulus is a linear relationship to foam stability.4. Evaluation of foam drive performance with hyperthermic & hyperhaline foam system. The extents of EOR with hyperthermic & hyperhaline foam system are evaluated through high temperature physical simulation apparatus and the extents of EOR with foam system under different patterns are compared. Research results show that hyperthermic & hyperhaline foam system can increase oil recovery of tube model by 27.1% and oil recovery of two-dimensional rectangular model by 31%. Foam drive with hyperthermic & hyperhaline foam system is a feasible method to increase oil recovery of hyperthermic & hyperhaline reservoirs.