Research On Remaining Oil Distribution And Adjusting Potential Exploitation Method In Secondary Development Of Block Z

Z blocks in 2009 started the project of old oil fields in the secondary development reconstruction pattern structure,using two sets of well pattern development,adjustment object for the effective thickness of less than 0.5 m poor thin reservoir and untabulated reservoir remaining oil accumulation horizon,to develop better G?,G?reservoir group of sequestration,temporarily not production.After nearly 10 years development,the block under the low degree of water flooding control,the problem such as water cut rising fast,need to the original seal of G?,G?reservoir group implement fill holes,and well pattern well spacing and layering water injection interval optimization.Based on the study of the remaining oil potential,the object and timing of hole filling were studied by numerical simulation,and the spacing of the interval pattern after hole filling was optimized.The following results have been achieved:The potential areas for hole filling were determined by the intersection of oil saturation and residual reserve abundance.According to Z block G oil layer data,complete the fine 3 d geological modeling and numerical simulation model of the production history matching,using the ae and the relationship of shunt volume moisture content chart combined with the relative permeability curve to determine the saturation line were 0.35,0.45,average remaining reserves abundance boundaries for the entire district reserves abundance 5×10~4t/km~2,extraction model of each grid point in the oil saturation and remaining reserves abundance map where joint evaluation,the remaining oil is divided into six categories and clearly have reperforating potential areas,overcome the limitations of the single index evaluation of remaining oil potential.The numerical simulation method is used to predict the development effect of the hole filling scheme and the hole filling time,and to optimize the well spacing,comprehensive technical index,"development equilibrium index"and economic index after the hole filling.In this paper,two parameters of effective thickness of small layer and water flooding degree of small layer in a single well were selected,and a hole replenishment scheme was developed layer by layer in combination with the potential area.The optimal hole replenishment object was oil layer with effective thickness of more than 0.5m and water content of small layer lower than 97%.The design of well pattern spacing was carried out without changing the oil and water Wells,and the development effect of five-point normal pattern 106m well spacing was the best.The lorenz curve method and the proposed"development equilibrium index"were used to quantitatively evaluate the displacement equilibrium degree before and after the secondary development.The plane displacement equilibrium index increased by 0.1030,but the difference was still large.The injection and production displacement degree of each vertical small layer changed from a large difference to a relative equilibrium,and the development equilibrium index increased by 0.1057 and 0.0942,respectively.The combination scheme of stratified segments is developed by means of the optimal segmentation method.In this paper,a conceptual model was established for each influencing factor to determine its technical boundaries:the upper limit of the range of permeability in the interval was 4.5,the thickness of the interval was less than 8m,and the range of oil saturation in the interval was no more than 1.5.Five dynamic and static parameters of single well were selected,including permeability,porosity,effective thickness,oil saturation and pressure,and the comprehensive evaluation parameters of single well were determined by grey correlation analysis.Using the optimal segmentation method to interval in order and principle of a similar nature,the existing number of injection well segmented on the basis of interval subdivision scheme design,final optimization scheme for dividing the interval as well at this stage based on piecewise number 1,and ensure well block number 7 section,maximum recovery is expected to increase by 2.44%,the disparity is adjusted for differences in plane displacement equilibrium degree is more balanced,effectively improve the status of development of the secondary development of old oilfield has a certain guiding significance.