| Foam flooding is the important development measure of China's enhanced oil recovery,including foam flooding can take full advantage of the synergies between the chemicals,thus dramatically enhanced oil recovery.For high-temperature and high-salinity reservoirs,foam flooding faced two challenges.On the one hand,under the high temperature and salinity conditions,the foam has poor saline and thermal stability.On the other hand,the strong foam system what be selected and made in static experiment whether has the same excellent ability to enhance the oil recovery in the dynamic experiment or not.In this paper,based on the Black 96 reservoir of Jilin Oil Field conditions(temperature 97?,salinity 46000mg/L)and crude oil properties,selecting anti-temperature salt-tolerant foam displacing agent and studying on the mobility control ability of the foam in the porous media,the main contents are as follows:(1)Selected and evaluated nine kinds of the new anti-temperature salt-tolerant surfactants on four aspects as follow:the concentration,anti-temperature ability,salt-tolerant ability and anti-oil ability.Determined the complex system of anionic surfactant LW based agent had outstanding abilities in high temperature and high salinity conditions.(2)In order to optimize the foam system,compounded the main agent LW with the anionic surfactants,cationic surfactants,amphoteric surfactants and nonionic surfactants in different mass ratios,making sure the LW with nonionic surfactant in 3:7 and LW with amphoteric surfactants surfactant in 9:1.(3)Based on the compound foam systems,in order to improve the foam ability we added several foam stabilizers through adjusting their proportions and compounding with each other and studied on some features in long-term stability of the thermohaline.Finally,we decided the foam system LH-8 as the displacing agent that suited for the Black 96 reservoir of Jilin Oil Field reservoir through the 3-month-long stability of the thermohaline experiment.(4)Scanned foam micro-morphology by electron microscope to analysis the foam abundance,thickness and structure of foam film what are related to the foam stability.(5)Through no oil man-made cores of displacement experiments to analysis the mobility control and EOR of the foam systems that had the same foam hight and the same viscosity as well,while had obvious difference in half-time.The results showed that the resistance factor is gorwing with the increasing half-time in the same permeability condition.When injected the same foam system into different cores,the larger of the core permeability,the higher of the restance factors were.However,the the permeability over 200mD,the growing rate of resistance factor was going to be gently.(6)In the high temperature and salinity conditions,through the displacemnt experiments in oil man-made core the permeability from OmD to 1300mD to study the mobility control ability and EOR of the four foam systems which from the static selection experiment what had the same foam hight and the same viscosity as well,while had obvious difference in half-time.The conlusoin showed that in the same permeability,the longer of the half-time was,the stronger of the foam mobility control was in porous media and higher EOR as well.When injected the same foam system into different cores,the larger of the core permeability,the stronger of the foam mobility control was.(7)Through the parallel core flooding experiments,research core heterogeneity of foam flooding the seepage law and oil displacement efficiency.Research core heterogeneity affect on foam flooding seepage law and oil displacement efficiency.The results showed we can improve the foam stability by compounding and adding stabilizers in the high-temperature and salinity reservoirs condition.It is good for the strong foam systems building the efficiency mobility contro in porous media so that being positive to EOR.It has extremely value of research and application development. |
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