Generate the graphs shown in slides 70 and 72.ģ) Discuss the differences in the Vp models obtained using Whyllie vs. water saturation and fluid computed in question 1. Use equation 1 (slide 64) to compute Ksat and equations in slide 61 to obtain Vp and Vs. Code the Whyllie equation shown in slide 60 and create the corresponding graph.ī) Use the Biot-Gassmann approach for gas (slide 70) and oil (slide 72) saturated sandstone for reservoir porosity=33%, Kmatrix=40 Gpa, Kdry=3.25 Gpa, Kw=2.38 Gpa, Koil=1.0 Gpa, Kgas=0.021 Gpa, Shear Modulus=3.3 Gpa.Ĭompute the fluid bulk modulus as a function of water saturation (0% – 100%) for gas-water and oil-water saturated rock (slide 67). substituting gas for oil) in the water saturated sandstone.Ī) Use the Whyllie equation for sandstone with porosity=33%, velocities (m/s) matrix=5700, water=1600, oil=1300, gas=300 to model saturated sandstone P-wave velocities. Water Saturation and varying pore fluid: Illustrate the effect of: a) varying water saturation to velocity (water saturation from 0% to 100%) and b) varying fluid type to velocity (i.e. Other combinations of elastic parameters such as P-impedance, Vp/Vs ratio and density are equally possible. Reference the source of your selected modeling parameters in your report.Ģ) Velocity vs. Pre-stack inversion transforms seismic angle or offset data into P-impedance, S-impedance and density volumes through integration of the seismic angle/offset gathers, well data and a basic stratigraphic interpretation. Select appropriate modeling parameters from the literature and class notes. Code the bulk density equation shown in slide 50 to create the graph shown in slide 51.ī) Repeat for a different “reservoir” rock of your choice (e.g. substituting gas for oil) in the water saturated sandstone.Ī) Sandstone porosity=33%, densities (g/cc) matrix=2.65, water=1, oil=0.8, gas=0.001. Water Saturation and varying pore fluid: Illustrate the effect of: a) varying water saturation to density (water saturation from 0% to 100%) and b) varying fluid type to density (i.e. You can refer to Chapters 1 & 2 of Chopra and Castagna AVO book for more detailed presentation.ġ) Density vs. Submit a word document with text and figures justifying your answers.įor this assignment we will use the slides on rock physics provided by Hampson Russell (available on Blackboard) to illustrate some basic concepts in rock physics and fluid substitution.

Hampson russell fluid substitution