A Study On Tight Oil Well Logging Technology In Bie-series Wells Area Changling Depression

The result for fine logging evaluation are the basis and evidence for unconventional tight oil reservoirs exploration and development.The crucial process for Well logging evaluation of tight oil reservoir including establish reservoir classification standard according to well-logging data,the calculation model for reservoir parameters,the fluid identification model,the rock brittleness and the the calculation method for ground stress.The characteristics for complex microscopic pore structure are the key factors to control the tight oil reservoir percolation capacity,the liquid production property and the reservoir productivity distribution,it is the key factor for tight oil development.Based on the analysis of core thin film,scanning electron microscope,whole rock,high-pressure mercury pressure and nuclear magnetic data from the wells in Changling depression,III sand group of the fourth spring section is characterized by high fine lithology,high clay content,strong compaction and quartz secondary enlargement,which leads to low porosity and permeability of reservoir,and the main types of porosity are inter-practical and secondary corrosion hole primarily,with large pore throat ratio.The subsection power function method is used to establish the R10 conversion formula of nuclear magnetic resonance response and pseudo capillary pressure.According to the data of core data such as R10,Kong Hou ratio and permeability,the reservoir is divided into 4 types.A formula for obtaining R10 from conventional logging curves is established,and logging evaluation of tight oil reservoirs in the study area is realized.The calculation method for clay content and porosity in the research area is established by core scale logging.Based on the pseudo capillary parameter Rlo,the permeability parameter calculation model has effectively depicted the complex pore structure characteristics of tight oil reservoirs.Based on the theory of double pore conducting model,the classification of double porosity(large and micro pores)and the fine study of formation water resistivity are carried out,and the parameters of the inversion model are optimized and a reasonable calculation model of water saturation is established.According to the theory of elastic wave,the method of calculating rock mechanics parameters,brittle parameters and ground stress according to the time difference of vertical and horizontal wave is established,and the minimum horizontal stress difference and the distribution of brittleness parameters are given,which provides the basis for further fracturing construction.The characteristics of well logging response in typical oil-water layer are studied according to the four property relationship,and the ability to reflect the fluid properties of the reservoir is studied by cross graph technique.It is considered that the degree of salinity,the increase of resistance,the ratio of vertical and horizontal wave speed,the wave impedance,the Poisson's ratio and the compression coefficient are themain sensitive parameters to identify the properties of the reservoir fluid.Using Fisher discriminant technology,the main sensitive parameters are constructed into two space vector parameters,and the identification standard is established based on these two parameters.When undertaking old well review for the Bie-series wells in Changling depression,research results of reservoir classification,reservoir parameter calculation and fluid identification,brittleness and stress parameters calculation are applied.The oil test potential layer of 4 wells in Changling depression is put forward,and the research results are effectively applied.