| The reservoir porosity and permeability of this study area are extremely low,the underground lithology is complex,and the degree of fracture development is high.It is difficult to identify different types of fractures.In view of the complex situation of the work area,the thesis aims to explore the characteristics of fractured tight reservoirs,the logging response of different types of fractures,and establish a comprehensive evaluation method for fractured tight reservoirs based on lithology,lithofacies and physical property data.The thesis explores the response law between the various attributes of tight reservoirs and establishes a model for the comprehensive characterization and evaluation of tight reservoirs,which can achieve a small theoretical breakthrough in this field.First,study the difference of rock minerals between fractures and non-fractured sections of tight sandstone reservoirs,the characteristics of porosity and permeability development between fractures and non-fractures in tight sandstone reservoirs,and analyze the pore space structure of fractures and non-fractures in tight sandstone reservoirs according to the lithology.The similarities and differences between the non-fractured section and the fractured section are discussed.Second,the response characteristics of the dual lateral resistivity logging numerical simulation are established,the uniform geological model is established,and the electrode coefficients of the deep and shallow lateral directions are calculated.A geological model of dual lateral logging with a single fracture and two fractures was established,and the voltage distribution and current line distribution at each point of the fractured tight reservoir were obtained.The study simulates the response characteristics of fractures when the fracture angle,opening and mud resistivity change,that is,the variation rules and differences of the deep and shallow resistivities of the fractures are obtained,and the logging-specific response characteristics and characteristics of different types of fractures in tight reservoirs are established.Characterization method.Then,under the guidance of forward modeling,a calculation method for fracture parameters was established.The core and logging curves are used to scale each other,the characteristic function is established,and the fracture identification model is obtained.The BP neural network and wavelet multi-scale transformation are used to identify different types of fractures.Through nonlinear fitting,the parameter calculation methods of fracture dip and fracture opening are obtained respectively.Finally,the relationship and law between the fracture parameters of tight reservoirs were studied,and the evaluation model of “fracture sweet spots” suitable for the target interval of tight reservoirs in the study area was established.This paper studies the characteristics and laws of dual-lateral numerical simulation of different types of fractures in tight reservoirs,establishes the relationships and laws of various parameters of different types of fractures in tight reservoirs,and obtains the evaluation method of "fracture sweet spots" in tight reservoirs. |
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