| In the research of low porosity and low permeability or dense fracture sandstone reservoir, the research of fracture is the most important.Not only do the fractures are main channel, but also is important reservoir space of oil and gas. The Kesheng2block of Kuche district is a typical low porosity and low permeability dense fracture sandstone reservoir, and the fracture is high heterogeneity. Conventional fractured models are based on ant tracking of seismic, but because of the insufficient of seismic interpretation. Taking the fracture parameters of IMF as hard data and basing the theory of core element simulation, put key point interpolation in through the analysis of fractures to control the model, complete the fracture modeling of target blocks by the sequential Gauss simulation method. The model depicts the fracture parameters’distribution characteristics and trends visually, and the prediction accuracy rate reaches above80%. The model provides effective geological model for later research about seepage behavior and heterogeneity of fracture, avoids the restriction brought by insufficient precision of seismic interpretation, and enriches the research methods of reservoir geological modeling.Through investigation of previous studies, using fracture research theory as guide, take fracture of Bashijiqike formation in Kesheng block of Kuche district as the research object. By the research of outcrops, cores, core wafers, FMI data, has completed the identification and fine description of fracture, and select the relevant algorithm to establish fracture model according to main controlling factors. The main work carried out and the results obtained are as follows:(1) According to the comprehensive application of core and FMI, the paper establish a integral set of method about fracture parameter identification and calculation. The recognition accuracy of the method reached to0.1mm, fracture pick-up rate reached80%. This paper has completed the fine description of fracture parameters and establish database for22wells in the study area through the method.(2) In research block, small fractures growth primarily, accounts for89.6%, big and middle fractures are just1.8%,8.6%. Fracture main strike direction are around SN and EW direction, the orientation of fractures tend to mainly NE and SW, the dip principal value range by45°～75°. Fracture density average by0.53/m, the fracture width range from0.1to0.4mm, the length of extending range by0.1-0.9m, the average fracture seam ranges from0.02%to0.08%; There are many types of fractures, X shear and mesh fractures are the main types.(3) The fracture develop generally in research block, the whole fractures show strong tectonic control, especially near the fault, the core of the anticline and wing strong deformation zone. In longitudinal, fractures are distributed mainly in the first section, the second section of Bashijiqike formation.The fracture parameters of third section is less than the first and second section of Bashijiqike formation, the fracture is been control by the fault in the upper of third section. In transverse, the continuity of fractures is poor and heterogeneity is significant.(4) The paper select the control points according to the analysis of control factors about anticline and fault zones in research block, and fit the relationship between the thickness and fracture density and seam, and then complete assigment.Select Sequential Gaussian stochastic simulation method to establish fracture density and seam model.realize the plane and three-dimensional prediction from every layers and any points. The paper has completed the verification with new well data, the overall accuracy rate reach to80%of model. |
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