Study On Reasonable Development Strategy Of JS Extra Low Permeability And High Saturation Reservoir

With the continuous development of oil field exploration and development,the proportion of ultra-low permeability reserves in domestic new exploration oil reserves is increasing day by day.For a long time in the future,the exploitation of ultra-low permeability oil and gas reservoir will provide strong support for the increase of reserves and production and the stabilization of energy supply in China.In the process of ultra-low permeability reservoir exploitation,it is found that due to the high saturation pressure and small ground saturation pressure difference of some reservoirs,the effective exploitation of ultra-low permeability reservoir is deeply affected.Therefore,the research on the reasonable development strategy of ultra-low permeability and high saturation reservoir is of great significance to the development of China's petroleum industry.In this paper,based on a large number of literature,taking JS oilfield in Songliao Basin as an example,based on its characteristics of ultra-low permeability,high saturation pressure and low ground saturation pressure difference,the reasonable development strategy of ultra-low permeability and high saturation reservoir is summarized by combining numerical simulation and theoretical research.First of all,considering the comprehensive influence of starting pressure gradient and pressure-sensitive effect,based on the elliptic percolation theory and the law of average mass conservation,the productivity calculation formula of fracturing well is derived,and the influence of starting pressure gradient,pressure-sensitive effect,number of fracturing fractures,fracture length,fracture conductivity energy and deformation coefficient on the productivity of fracturing well is analyzed;secondly,by means of numerical simulation,the productivity of fracturing well is reasonable The development mode,well pattern main control factor and well pattern form optimization are studied.On the basis of reasonable development mode,the characteristics of high saturation reservoir are fully considered,and combined with the actual development status,the reasonable well pattern density,reasonable pressure system and reasonable injection production speed are optimized for the target area,at the same time,suggestions are provided for the reasonable development of JS oilfield.The results show that:in the whole process of high saturation reservoir depletion exploitation,the change trend of gas oil ratio can be divided into three stages:the injection production ratio is stable first,then slightly reduced,rapidly increased,reaching the peak value,and then decreased to stable;for high saturation reservoir,in the early stage of exploitation,the oil production of depletion exploitation is much higher than that of waterflooding exploitation,and in the later stage of exploitation,waterflooding exploitation is shown in Fig Significant effect;long fracture,low diversion,non-uniform distribution and non equal length fracture are conducive to uniform oil recovery of ultra-low permeability reservoir;during initial production,ultra-low permeability and high saturation reservoir needs 40-60 wells/km~2 for production,which can achieve about 30%oil recovery;high saturation reservoir needs to adjust the injection production ratio according to the change of production gas oil ratio,so as to obtain a higher degree of production.The research results have theoretical significance for the effective development of ultra-low permeability and high saturation reservoirs in JS oilfield.