The Research On Conformability Of Different Drive System To Low Permeability Reservoir

A comprehensive study has been made on the problems of low permeability reservoir, summing up the results of their predecessors on the basis of low permeability reservoir. Polymer flooding can be carried out,based on this the research on conformability of different drive system to low permeability reservoir has been done. The molecular weight of polymer is identified through flow test; Result through different kinds of surfactant can identify the formulation of different flooding systems; The main task is on the homogeneous core of 300×10-3μm 2, 150×10-3μm 2 and 50×10-3μm 2and non-core to carry out single polymer flooding,nonalkali compound flooding ,ternary compound flooding,weak alkali ternary compound flooding system and strong alkali ternary compound flooding. The oil displacement efficiency above flooding system is evaluated,and suitable low permeability reservoir of oil displacement system can be found. The results show that the betaine surfactant BS may form the ultra lower interfacial tension of 10-3mN/m magnitude in wide concentration range under non-alkali condition. The independent system of heavy aklyl benzenes sulfonate surfactant SY is unable to reach the ultra lower interfacial tension of 10-3mN/m magnitude,joining the right amount strong alkali in the system, the water-oil interfacial tension could reach ultra low, optimum alkali content would increase along with the increasing surfactant. The concentration of surfactant HLX for binary compound flooding rang from0.03% to 0.3%,and at the same time the concentration of the polymer is 1500mg/L, which can reach the ultra lower interfacial tension of 10-3mN/m with crude oil. The result of research on physical analogue experiments shows that: the surfactant BS with sodium carbonate flooding has better driving efficiency totally in view of the homogeneous and heterogeneous models, is suit for low permeability reservoir; The efficiency of HLX nonalkali compound flooding, strong alkali ternary compound flooding with SY, the surfactant BS compound flooding and the surfactant Ss weak alkali ternary compound flooding are correspondent. Single polymer flooding has weak ability to enhancing the recovery.