AVO & Rock Property Modeling

Rock property modeling offers organizing and visualizing geology and geophysical data for prioritizing projects.


Porosity modeling
 
XXX well logs
XXX Well Logs

Typical AVO Responses

   

The XXX well logs could be similar to typical Gulf Coast gas sand AVO responses. 


The target reservoirs could be the sands of the Early-Mid Miocene formations between 1.0 –3.0 sec. two-way time.

AVO Workflow

(1) Pre-Stack Depth Migration (PSDM) (2) Final PSDM Migration Velocity Analysis (MVA) (3) Convert from Offset to Angle Gathers using MVA velocities (4) AVO Attributes Computation

AVO Attributes

(1) Intercept = the P-wave reflection amplitude at zero offset that is related to acoustic impedance and porosity (2) Gradient = the P-wave reflection amplitude minus twice the S-wave reflection amplitude, that is related to fluid saturation in reservoir rocks (3) Poisson’s ratio = the sum of the intercept and the gradient is the approx. Poisson’s ratio change, which is an indicator of fluid saturation (4) S-wave = the difference of the intercept and the gradient, after scaling, is the approximate S-wave reflectivity

Seislink Recommendations

Interval Velocity in Depth Domain

It is recommended to use seismic PSDM / PSTM stacked volumes, velocity data for pore pressure prediction, and AVO attributes to interpret the 3D structures and the related amplitude anomalies for the reservoir estimation. A new 3D seismic survey with denser bin size should be acquired to avoid the data aliasing effects on the steep-dip events and to monitor the reservoir changes.


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