Viscous Crude Oil Flooding Improvement Projects For Reservoir Block Ba 48

Viscous crude oil reservoir block Ba 48 is lithology-structural and so the reservoir zonation is controlled by dual factors,structure and lithology. The reservoir is mainly developed in groupⅢ, subdivided intoⅢ1,Ⅲ2.TheⅢ1 belongs to the mesoporosity-low permeability reservoir in the hole with an average porosity of 21.5%,and effective permeability of 34.81×10^-3μm².TheⅢ2 has an average porosity of 12.7% and variation in the effective permeability properties, it is overall meso-low-porosity and mesopermeability.The formation crude is of high viscosity, density, and flow resistance, it has an average density of 0.8659g/cm3, and a viscosity of 56mPa?s～110mPa?s,therefore, the displacement efficiency in the exploitation is low, the use of conventional mining methods has a low efficiency.This paper has done further research in how to improve the swept scope of water flooding and the conventional mining method recovery in the existing work system.The geological reserves of viscous crude oil reservoir block Ba 48 in groupⅢare 202×104t,rated recovery is 19%,large remaining oil reserves of water flooding.This paper has studied on the distribution of the remaining oil in the plane and longitudinal of this block on the basis of the geologic feature of viscous crude oil reservoir block Ba 48. The results show that the distribution area ofⅢ2 is larger,and the reservoir is mainly distributed in the northern block,theⅢ1 reservoir is mainly distributed in the southern block.Part of the geological layers has a recovery of less than 10%, and the others about 20%, ineffective water flooding.Based on the geologic feature of reservoir block Ba 48, and summarized the influence of waterflood residual oil distribution factor under the existing working system, proposed sub-injection and oil wells turn to improve the effect of water flooding for viscous crude oil reservoir block Ba 48 under the conditions of column and technology allowed.Viscous crude oil reservoir block Ba 48 in groupⅢhas 13 production wells and 6 injection wells,based on the analysis of the current daily output of oil wells, the initial daily injection allocation of 13 oil wells is 129.4m3,the average daily injection allocation of a single well is 21.57m3, implemented sub-injection in the case of constant total, oneⅢ11,Ⅲ12 for the first injection section,andⅢ₁3,Ⅲ₁4,Ⅲ₁5,Ⅲ₂1,Ⅲ₂2 andⅢ₂3 for the second injection section. Four sub-injection programs have been adopted,the sub-injection effects of Ba 48-3 and Ba 48-38 are better,increased the recovery level at 2.2 percentage points comparing with the existing working system,increased oil 45298t.Some of the injector producer distance is larger from the point of injection/production relationship and need further improvements.Implementation of the oil wells turn of Ba 48-16,used interpolation to determine the injection flow rate of Ba 48-16,re-prorated production for each producer.Comparing with the existing working system,increased the recovery level of 1.3 percentage points,increased oil 26765t.Achieved efficient water flooding for viscous crude oil reservoir block Ba 48, had an important role in guiding the efficient development next step in this block.