Print this pageAAPG ANNUAL CONFERENCE AND EXHIBITION
Making the Next Giant Leap in Geosciences
April 10-13, 2011, Houston, Texas, USA
Petrophysics and Rock Physics Modeling to Improve Seismic Reservoir Characterization — Case Study of Lower Hackberry Sandstone
(1) Fugro-Jason Inc., Houston, TX.
(2) PXP, Lafayette, TX.
An integrated workflow of Petrophysical Analysis and Rock Physics Modeling has been applied to improve the reservoir characterization in lower Hackberry sands. Fluid replacement was applied to assess sensitivity of elastic rock properties to pore fluid type in the reservoir. It was found that a layer of abnormally soft shale overlays the sand unit in the investigated well, resulting in a large contrast in acoustic impedance that overshadowed the fluid effect. Shale replacement with normal shale properties was applied to examine sensitivity to the overlying shale type. Fluid replacement was applied again after shale replacement to evaluate fluid sensitivity. Synthetic seismic traces were generated for the different fluid types before and after shale replacement. Seismic responses were estimated by comparing synthetic seismic traces from the combinations of overlying shale and fluid types.
Further study involved AVO(Amplitude vs. Offset) attribute analysis to estimate the feasibility of reservoir characterization by seismic inversion. The integrated process also included study of porosity and sand thickness sensitivity. Reservoir bodies captured in different cases were examined and compared to evaluate the sensitivities at seismic resolution.
The integrated process was also applied to the deeper Nodosaria sand unit. Applying this process in the Hackberry Embayment area provided geophysicists and geologists with detailed Petrophysical and Rock Physics information and, therefore, greater confidence in reservoir characterization.