Study On Developing Potentialities Of La-Sa-Xing Oilfields In Daqing Region

La-Sa-Xing Oilfields is located in the Depression Placanticline anticline belt in the Central Basin,and oil generation and oil storage are best in the basin.Deposition system is the major river - delta system,and lithology is mainly the principle of fine sandstone and siltstone.When Air permeability of the major reservoirs is over 0.5μm~2,permeability is amongst 0.02～0.8μm~2 in the thin sand.Reservoir is laminar anticlinal structure reservoir when permeability of the useless reservoir is amongst 0.001～0.05μm~2.The crude oil is green oil,and the paraffin content reaches to 20 ~ 30 percent.Calculated by volumetric method,proved geologic reserve is 41.9429×10~8t,producing geologic reserve is 41.7426×10~8t, recoverable reserves is 21.599×10~8t and the quantity of remaining recoverable oil is 3.1119×10~8t.La-Sa-Xing Oilfields,placed on production from June 1960,has experienced on the production stage,stable yields stage and high production stage,now the oil field comes to the double extra high production declining stage.By the end of 2008,the accumulative oil production is 18.4880×10~8t,the producing geologic reserve is 44.29 percent,and the producing recoverable reserves is 85.59 percent.In 2008,oil production is 3275.3×10~8t,the oil production rate is 0.78 percent,the recoverable reserves oil production rate is 9.76 percent,and the composite water is 91.3 percent.To improve the development effect of double extra high development stage which means increase recoverable reserves,constant flow rate and slow down decline rate,the potentiality of remaining oil has to be figured out,and scientific development strategies have to be worked out.Based on phase permeability curve,hermetic core hole data and dynamic development data,forecasting method of prospective potentiality for the classified oil layers is set up which is closer to the true situation of Lasaxing oilfield.The oilfield development permeability is calculated,which provides scientific foundation for establishing development technical policy and compiling development program.According to the waterflooding characteristic curve and effective permeability curve, dynamic geological reserves equation for the classified oil layers in the condition of multi-layer production is established,with which producing reserves can be calculated.Through analyzing the hermetic core hole data in Lasaxing oilfield,water flushed zones has been figured out.On the basic of the core hole data and phase permeability curve, calculation procedure of remaining oil for every oil layer of Lasaxing Oilfield has been established.The distribution of remaining oil is measured.The relation of R - f_w for different types of oil layer can be built by statistics regression method through the use of the core hole data,which can predict the potentiality of water displacement recovery for different types of oil layer.On the basis of laboratory effective permeability test data and the core hole data,the displacement efficiency equation of water drive,polymer flooding and ASP have been set up,and relevant ultimate displacement efficiency equations have also been defined.The relationship between conformance efficiency and water cut is set up by the use of hermetic core hole data,which can forecast the conformance efficiencies of every oil layer with extreme containing water.The enhanced recovery scheme of oil field is optimized through using probabilistic decision analysis method,and the prospective potentiality is calculated.