Application Of The Numerical Well Test In BZ2 Oilfield

Well test can determine the reservoir parameters,boundary condition,pressure drop and pressure build-up well testing,are widely used.At present well test interpretation is used by the conventional technologies,but the interpretation results are unreasonable because of the assumed conditions: interference without adjacent wells;homogeneous reservoir;normal boundary.Through the research of papers and application in oilfield,these problems are solved by the numerical well testing methods.First,a three-phase(oil,gas and water)seepage mathematical model was established according to the theories of seepage mechanics and material balance.Second,time and spatial discretization was done on this model with the Voronoi network technology so that oil and gas reservoirs were dispersed into multiple grid cells.Finally,the iteration method was used for computing the pressure distribution on each grid cell and physical property parameters.As a result,actual geological conditions of oil and gas reservoirs were presented with delicate Voronoi grids in this technology,which turned out to be an elaborate testing interpretation.Compared with the conventional technologies,Voronoi bound both local fine grids and basic coarse grids together by using numerical fine grids at peripheries of well shaft and faults while sparse basic grids at the areas relatively distant from the well.In this way,geological characteristics of oil/gas reservoirs were definitely described and grid data was minimized as well,resulting in an increased arithmetic speed and precision in well testing.This technology is widely used in BZ2 oilfield.The problems of interference with adjacent wells in heterogeneity complex reservoir are solved by numerical well testing methods to improve the fitting accuracy,thus the results are more reasonable.The connectivity between wells is determined by this technology.Well group formation pressure distribution is analyzed by this technology.Thus the adjustments between oil wells and remaining oil are carried out by the result.Practical application shows numerical well testing technology in complex oil and gas reservoir has better application effect,succeeded in solving the actual problems in the Bohai oilfield,and has better prospect.