The low frequency components of seismic signals suffer less from scattering and attenuation in the process of seismic wave propagation and can penetrate deeper strata. Thus, low frequencies contain more energy information related to the fluid-saturated reservoirs comparing to the high frequencies of seismic signals. In order to extract the energy attribute related to hydrocarbon reservoirs from the low-frequency contents of seismic signals, based on the asymptotic representation of frequency-dependent reflection of the pore-elastic theory related to fluid-saturated medium, we derive a novel equation to calculate the reservoir energy density and establish a simple workflow to calculate the reservoir energy density based on low frequency information of seismic signals. First, within the low-frequency range (0–30 Hz), we construct an objective function to determine the optimal frequency using the energy densities calculated from the post-stack seismic trace nearby bore-hole. Then, we can calculate the reservoir energy density by using the instantaneous spectra of optimal frequency at the low frequency end of the seismic spectrum. Tests on synthetic seismic data and a field seismic data demonstrate that reservoir energy density show excellent imaging effect for fluid-saturated reservoirs and less affected by the background interference of elastic layers. Thus, the proposed method is feasible to detect the location and spatial distribution of hydrocarbon reservoirs and provide a new way for reservoir delineation.
Presentation Date: Wednesday, September 18, 2019
Session Start Time: 1:50 PM
Presentation Time: 3:30 PM
Presentation Type: Oral