| In recent years, the synthesis of high temperature resistant polymer changes the view that polymer flooding is not suitable for high-temperature reservoir. The study of high temperature resistant polymer properties is not yet complete. For high-temperature reservoir is lack of reasonable theory to carry out high-temperature polymer flooding. In this paper, SHUANGHE oil field Ⅶ1-3 strata reservoir with temperature of 95 ℃ is choosen for studying the hydrolysis degree 、 structural stability and rheology of high temperature resistant polymer. And experimental study of flooding performance is carried out in this condition. The following conclusions can be obtained: the hydrolysis degree of high temperature resistant polymer increasing with the increase of aging time and reservoir temperature and the structure of the AMPS group did not occur hydrolysis. AFM characterization results show that: high-temperature polymers were loose dendritic distribution before the aging former and the dendritic length is shorter after 30 days, then the loose dendritic distribution into "non" shaped comb distribution after 60 days. After aging for 90 days polymer forms a diameter of 10 m thick sheet selection about short aggregation. The rheological results show that: viscosity retention rate of high temperature resistant polymer is between 84%~90% after 90 days and the viscoelastic parameters of retention rate was 49%~89%.The excellent viscoelastic properties of high temperature resistant polymers at high temperature can not only improve sweep efficiency, but also can improve the microcosmic oil displacement efficiency in a certain range. After 90 days of high-temperature oxidation,high temperature polymer molecular structure changes, although to some extent, but the performance retention rate remained at the ideal range. The best slug of high temperature polymer flooding is 1500 mg / L concentration with 0.6PV. High temperature polymers suitable for heterogeneous reservoir permeability ratio less than 4. |
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