The Study On Application Method Of Frequency-dependent AVO Analysis Of Sulige Gas Reservoir

Tight gas reservoirs play an increasingly important role in reserves growth and energy supply.The distribution of tight gas reservoirs in China is extensive,diverse,and has great potential.The Ordos Basin is China's main natural gas producing area,and the Sulige gas field in the Ordos Basin is a typical tight sandstone gas reservoir.The formation mechanism and distribution law of tight gas reservoirs in the actual research area are complex,difficult to explore and technically demanding,and conventional seismic fluid detection and AVO analysis techniques are difficult to work.Aiming at the exploration difficulties in the study area,this paper studies and analyzes the attenuation and frequency-dependent characteristics of the tight gas layer in the Sulige area through the analysis of petrophysical theory and the measured data of the broadband core.A typical tight gas reservoir model is established based on the well data of the drilling well in the study area,and the seismic prestack gather is simulated.The vibrating medium seismic wave propagation theory is used to calculate and analyze the characteristics of the actual reservoir frequency-dependent AVO response.The prestack 2D seismic profile is inverted.By constructing the frequency-dependent attribute parameters of the tight gas layer,the two-dimensional frequency-dependent property profile of the study area is calculated.By comparing with the actual drilling test results,the calculated frequency-dependent attribute profiles have higher consistency,and the coincidence rate is higher.This paper can provide an effective way to predict tight sandstone gas reservoirs and improve the reliability and accuracy of their prediction results.