Application Of Pre-stack Elastic Wave Impedance Inversion In Yanbei 1 Well Area

In this paper, we study on the abdomen of junggar basin YanBei 1 wellblock as the backing,In rock physics and AVO theoretical and angles of prestack elastic wave impedance inversion theory, on the basis of using prestack data extract rich elastic parameters, improve the group of baikouquan Triassic set of fan delta front in favor of the accuracy of reservoir and reservoir evaluation. And explore the prestack elastic wave impedance inversion method, to predict the group of baikouquan Triassic set of oil layer distribution and development characteristics of sand body, studied the lateral variation of reservoir.The group of baikouquan 2 of YanBei 1 wellblock major reservoir for a set of fan delta front subfacies of underwater distributary channel, lithology of gray glutenite of gray, brown, violet and grey and brown glutenite, single sand layer thickness commonly 4?15 m, reservoir with thin thickness, physical properties on low porosity, low permeability, the average strong, poroperm relationship is complex, the reservoir lateral variation is big, therefore in the present exploration, effective reservoir prediction and identification of oiliness and difficult.In 5 Wells in the area are the calibration curve environment such as pretreatment of this basis, using the rock physics modeling method to predict the shear wave curve, the group of Triassic baikouquan geological data in the region chose three eligible for low and middle hole rock physics model (Xu-White, Krief model, CriticalPhi model) model, and compares the prediction results analysis, Xu White model accuracy is best, shear wave and the measured shear wave forecasting error is minimal. Based on rock physics for prestack elastic parameter optimization of Vp/Vs divided reservoir types and the prediction of favorable reservoir distribution laws. Press and Shear wave velocity ratio is less than 1.72 for ? reservoir,1.72? 1.76 for ? kind of reservoir, reservoir is greater than 1.76 for ? class. Predicting effective reservoir the group of baikouquan 1 covers an area of 53.8 km2; The group of baikouquan 2 covers an area of 124.5 km2.Through AVO modeling, YanBei 1 well area in the group of Triassic baikouquan on the forward modeling gathers, reservoir top calibrates set on the peak of wave reflection amplitude with decreases with the increase of source-receiver distance characteristics, is a typical class of AVO abnormal response characteristics, for the follow-up of elastic wave impedance inversion provide reliable AVO types and standards. Then according to the wavelet consistency, synthetic seismogram, regression curve fitting methods such as monitoring prestack elastic wave impedance inversion reservoir prediction effect is good or bad. Through the above analysis, YanBei 1 wellblock prestack elastic wave impedance inversion quality is better.This paper mainly studies the stack data inversion through different angles to get the press wave and shear velocity ratio, and press and shear wave impedance, poisson's ratio, Lambda-Rho and Mu-Rho, and other important elastic parameters, such as elastic parameters obtained by using intersection, and the elastic parameter is used to identify the oil and gas in the region, the deployment location suggest two YanBei 4, YanBei 5 Wells. YanBei 4 in the group of Triassic baikouquan see oil stains, ready to test. Confirmed the method in complex reservoir description and fluid identification has the advantages of the practicability of the method.