Study On Synergistic Effects Of Hydrophobic Associated Polymers And Surfactants

With the exploitation of oil well coming into the tertiary recovery stage,fracturing technology exhibits its advantages in increasing production of oil and gas.However,the usage of water-based fracturing fluid would result in secondary damage on stratum,and surfactan-based fracturing fluid possesses the shortcoming of high cost.In order to overcome those disadvantages,developing a kind of fracturing fluid with high quality,low cost and low damage has become our primary goal.On the basis of previous research,we synthesized two kinds of hydrophobic associated polymers(HAP)with two compounds as hydrophobic monomer.The effect of experimental factors on the performance of polymer solution has been fully discussed and analyzed,and the optimal preparation condition was confirmed.The FTIR and NMR spectrums were used to characterize the molecular structure of hydrophobic monomer and copolymer.The synergetic effects of HAP and different kinds of surfactant were investigated via macrorheology,microscopic fluorescence spectrum and electron microscope in aqueous solution.Novel fracturing fluid was developed and applied in oil production process.The optimum synthetic conditions are listed as follows:the dosage of initiator was 0.2 wt%of the total amount of monomer,polymerization temperature was 42 ~oC,reaction time was 6h,mass percentage of hydrophobic and total monomers were 1%and 20%.It is shown that when the polymer concentration reached a certain value,the viscosity of two polymer solution increased sharply due to the hydrophobic association.What is more,the interaction between HAP and CTAB is driven by electrostatic force and hydrophobic interaction.Therefore,the viscosity of polymer solution decreased sharply when CTAB was added to the polymer solution,meanwhile the salinity tolerance performance was not enhanced.The variation trend of interaction between SDS and HAP strictly meets the three-stage growth model.With the adding of SDS,the viscosity of mixed system reached its peak and then decreased.The variation trend of compounded system(NVES and HAP)is similar,because NVES could form rod-like micelles and closely interwoven.