Study Of Petro-physical Parameters For Xujiahe Formations In Q Area Of Western Sichuan

In this paper, when came to problems of tight clastic deep reservoirs, in the Qregion of western Sichuan, that relate to reservoir prediction ithology identificationand fluid identification, lithology identification, fluid identification, we should carryout a precise analysis of the elastic physical parameters. At the same time, in order toset up effective technology system of inversion method constrained between well andseismic as well as to improve prediction service to the distribution of effectivereservoir. We’d better to closely combine with logging and seismic by means ofelastic physics parametersFirst of all, after we put regional standardization on the log curve which werederived from ten wells located in Xujiahe FM member4thand2nd, including naturalgamma, neutron logging, acoustic time and density logging, we can make use of thecross plot and fuzzy clustering method to identify lithology and utilize comprehensiveindex method and the normal probability distribution method to identify the fluid.Then kinds of models such as mineral content model, clay content model, porositymodel, water saturation model, permeability model should be established to calculatethe physical parameters of each well accurately, providing an accurate object of studyof the rock physics.Secondly, Xujiahe Fm lack the shear wave logging data, as is well known, wehave to, depending on mineral content andreservoir parameters, integratly use theeffective medium theory and empirical formula proposed by scholars at home andabroad, applying a variety of model, to predict S-wave, whose predicting outcomeswill be compared with the actual measurement of S-wave date. For that, the accuracyof the empirical formulas and the prediction model can be analyzed. When high-precision method is optimized to popularize among wells which lack S-wavedate in this area, good results is achieved, which provide guarantee for the study onelastic parametersThen, after obtaining accurate P-wave velocity and S-wave velocity combineswith density, porosity and volume of rock etc. parameters to calculate Young’smodulus, Shear modulus, Bulk modulus, Poisson’s ratio, λ, μ, etc. petro-physicalparameters. Analyzing the variation of petro-physical parameters with porosity, claycontent, gas saturation to establish petro-physical template of target area.Finally, by analyzing the sensitivity of petro-physical parameters to the reservoirlithology and fluid filter out some petro-physical parameters which can effectivelyidentify high-quality reservoir, lithology and fluid.