Numerical simulation to the influence of fracture parameters on P-wave anisotropy
DUAN Xi1,2, LIU Xiangjun1, LIANG Lixi1, XIONG Jian1
1. State Key Laboratory of Oil and Reservoir Geology and Exploitation(Southwest Petroleum University), Chengdu, Sichuan 610500, China; 2. Department of Science, Southwest Petroleum University, Chengdu, Sichuan 610500, China
Abstract:In the study of P-wave azimuthal anisotropy of natural fractures using seismic data,systematic sensitivity of P-wave attributes to fractures is not carried out.A non-uniform random fracture medium is produced through adjacent point fusion after setting fracture parameters based on digital image processing technology.Based on the acoustic wave theory,the acoustic wave field of the random discrete fracture model is numerically simulated.After calculating the acoustic velocity and attenuation coefficient of the azimuth of a survey line,the relationship between acoustic parameters and fracture distribution,orientation and density and fluid is analyzed to determine fracture orientation more accurately.Numerical simulation to the acoustic wave field of the random discrete fracture model shows that the influence of fracture parameters on acoustic attenuation coefficient is far greater than that on acoustic velocity,and the azimuth of the survey line corresponding to the minimum acoustic attenuation coefficient can be used to accurately determine fracture orientation.With the increase of fracture density,the relative change of attenuation coefficient decreases.With the increase of water saturation,the relative changes of acoustic velocity and attenuation coefficient increase first and then decrease.
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