Publications

Known for their internal heterogeneity, major constituent carbonate reservoirs (limestone or dolomite) are skeletal detritus with various trace elements and deposited with high primary porosity yet later experienced multiple post-depositional processes that deliberately altered its properties. The combination of biological origins resulted in high primary porosity and permeability coupled with chemical instability, which are responsible for the unique characteristics of carbonate reservoirs. Carbonate rock by nature has high seismic velocity with multiple reflectors across an interface, therefore obtaining good seismic imaging can be challenging. Simultaneous inversion incorporates acoustic impedance (Zp), shear impedance (Zs), and density (?) which can enhance the probability of identifying porosity and permeability as well as isolating the reservoir from non-reservoir rock. Fluid saturation also has a significant effect on seismic wave propagation. Different types of fluid saturations lead to the variation in Vp/Vs ratio, which is also one of the lithological indicators. When integrated with acoustic impedance cube using a Rock Physics Template, reservoir distribution with different level of qualities can be mapped in 3D. This paper shows that the application of simultaneous inversion combined with rock physics analysis could provide an alternative approach for reservoir characterization. This technique increases the level of confidence in evaluating reservoir properties as well as locating prospect zones.