| In this paper, for the layer beared calcium of Xingnan oilfield reservoir , the pore structure,clay minerals,relative permeability and sensitivity have been studied by a series of experiments.The results show that Xingnan oilfield reservoir of calcium clay minerals for the largest number of Iraq / mixed-layer, followed by as illite. For calcium-core of reservoir,the extent of speed-sensitive is medium-high, the critical velocity is from 0.25cm3/min to 0.75cm3/min, the more intense speed-sensitive level,the greater the critical velocity. Xingnan Zone reservoir water sensitivity of calcium is from middle-week to medium-high. Acid sensitivity of reservoir damaging little, we can take acid fracturing measures to improve the reservoir properties. With the PH value of the injected water increasing, permeability decreased slowly, when it went up to the critical pH, the penetration range of declining increases, the core belongs to the alkali-middle Min. On this basis, according to the characteristics of strong water sensitivity, using indoor flooding experiment, carried out researchs on enhanced oil recovery effects with different types of chemical agents, and anti-swelling effect ,experiment results showed that: when added cationic surfactant into injecting water with the concentration of 0.4% and the injected volume of 0.3PV, the effect is best, ,enhanced oil recovery can be increased by 10% comparing with water flooding, water permeability to the endpoint increased 163.4%, and pressure of injecting water reduced to 58.76%.
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