Reservoir Hydrocarbon Identification Method Based on Prestack Seismic Frequency-Dependent Anisotropic Inversion
Tianjun Lan, Zhaoyun Zong, Weihua Jia
Abstract
In an anisotropic reservoir, it is crucial to determine the anisotropic media fluid factor that corresponds to the reservoir’s anisotropic properties. To address the lack of research on accurate hydrocarbon identification and fluid factors in anisotropic reservoirs, relevant research work has been carried out. First, the relationship between the anisotropic parameters and the physical parameters of the fluid-bearing reservoir is discussed based on petrophysical mechanisms. Subsequently, a new anisotropic media fluid factor is developed that exhibits higher fluid sensitivity. According to some studies, the dispersion and attenuation of seismic waves will significantly affect the reservoir’s amplitude variation with offset and azimuth (AVAZ) response. Consequently, an anisotropic frequency-dependent reflection coefficient is constructed using the frequency-dependent anisotropic media fluid factor to better utilize the frequency information in seismic data. The pre-stack seismic frequency-dependent inversion method is employed to extract the abundant azimuthal anisotropy information and frequency information from the wide-azimuth seismic data. Synthetic and field data examples provide evidence of the high reliability and stability of the pre-stack seismic frequency-dependent anisotropic inversion method. The development of pre-stack seismic frequency-dependent inversion, based on AVAZ response and frequency response, offers a novel theoretical method for hydrocarbon identification in anisotropic reservoirs.