The Laboratory Expeirments Research On Bottom-water Heavy Oil Reservoir With Steam Flooding

The Nanpu35-2oil ifeld that is located in the central of Bohai Sea is a representativebottom water heavy oil reservoir. Its oil viscosity and reservoir permeability are very high andthe heterogeneity is also seirous. And the production well are watefrlooding owing to thebottom water coning, which has seirously hampered the effective development of the oilifeld.Therefore, the thesis study the mechanism of steam injection for the Nanpu35-2oilfieldwhich is mainly through lab expeirments, including the hot water and steam lfooding ofone-dimensional sand packed model expeirments research the heavy oil-water filtration lawand displacement characteirstic under different producing well-type and development mode,and also analyzed the mechanism of the bottom water reservoir bottom water coning, andthen the Nanpu35-2bottom water heavy oil reservoir is simulated by the physical model ofthe three-dimensional reservoir, the main controlling factors of bottom water coning has beenstudied. The results show that:1.The diffeernces between the heavy oil-water relative permeability is very large, andthe end point value of water relative permeability is generally negligible. When thetemperature irses, the relative permeability curve and the water saturation of permeabilityisopleth are irght movement and the two-phase region area and the irght end point value ofwater increased. It shows that the surface properties of reservoir rock is changed for heating,alteirng to water wet and increasing irreducible water saturation.2.Compared with hot waterlfooding, the steam lfooding’s temperature is higher, and thesteam flows better, the heating effects of formation is more obvious, and the swept volume ofthermal rfont is larger. And then the ifnal recovery is also more than hot waterlfooding.3.The contact area enlarges between the wellbore and layer and the pressure gradientreduce when the reservoir is produced by hoirzontal well. The decompression way changesfrom a point of vertical to a line of hoirzontal, increasing the decompression area and thenrepressing the cusping of displacing fluid and enlarging the hot lfuid’s swept volume toenhanced oil recovery.4.Optimizing the length of the hoirzontal well and the heigh of avoid shooting, it couldrepress the bottom water coning effectively. For the bottom water heavy oil reservoir，thecomposite oil recovery technology that the steam injection combines with horizontal well canbe used to develop.