Hampson Russell Tutorial -

The tutorial is honest about the limitations here—specifically the ill-posed nature of the inverse problem (where multiple Earth models fit the same seismic data). It introduces and sparse-spike inversion as regularization techniques to stabilize the solution. The final output, such as the Lambda-Rho (incompressibility) versus Mu-Rho (rigidity) crossplot, provides the ultimate lithology-fluid discriminant. Gas sands show low Lambda-Rho (compressible) but moderate Mu-Rho, whereas shales show high values for both.

The Hampson–Russell Tutorial: A Paradigm for Bridging Theory and Practice in AVO Analysis

The pedagogical climax of the tutorial is the (B vs. A). Instead of interpreting raw amplitudes, the user learns to interpret clusters on a crossplot. The tutorial explains that water sands, shales, and gas sands occupy distinct quadrants of the A-B plane. It introduces the concept of the Shuey background trend —the line defining "wet" sediments. Deviations from this line (specifically, decreasing gradient and decreasing intercept) indicate potential hydrocarbons. This transforms interpretation from a qualitative art ("is it bright?") into a quantitative science ("does it plot in the gas sand quadrant?"). hampson russell tutorial

A hallmark of the tutorial’s effectiveness is its visual interactivity. It allows users to input real well-log data (P-wave velocity, S-wave velocity, and density) and instantly observe the calculated reflectivity series. By toggling between the exact Zoeppritz solution and the Aki-Richards approximation, the user develops an intuitive understanding of when the approximations are valid (i.e., at small angles of incidence) and when they fail. This "visual mathematics" transforms abstract equations into a tangible, physical phenomenon, demonstrating that a gas sand will exhibit a characteristic increase in amplitude with offset (Class III AVO), while a hard overpressure shale might show a decrease.

The Hampson–Russell tutorial stands as a benchmark for technical education in applied geophysics. Its enduring value lies not in a single equation or algorithm, but in its integrated workflow: starting with well logs, applying rock physics, analyzing seismic angle gathers, crossplotting AVO attributes, and finally inverting for elastic properties. By forcing the user to execute these steps with real data, the tutorial transforms the geophysicist from a passive observer of seismic wiggles into an active quantitative interpreter. It teaches that an AVO anomaly is a hypothesis—one that must be tested against rock physics, calibrated with well logs, and validated by inversion. In an industry where drilling a dry hole can cost millions of dollars, the rigorous, step-by-step methodology of the Hampson–Russell tutorial remains an essential shield against the seductive but dangerous art of simply "picking bright spots." Gas sands show low Lambda-Rho (compressible) but moderate

The tutorial transitions from theory to application by addressing real-world seismic noise. It instructs users on how to generate (stacking multiple Common Depth Points to increase signal-to-noise ratio) and how to perform angle stacks (near, mid, and far). The key technical innovation taught here is the weighted stacking process to solve for intercept (A) and gradient (B).

The foundational hurdle in AVO analysis is the complexity of the Zoeppritz equations, which describe how seismic energy partitions at a boundary between two elastic media. The Hampson–Russell tutorials address this by immediately introducing the simplifying approximations—specifically the Aki-Richards and Shuey equations. Rather than overwhelming the user with matrix algebra, the tutorial breaks the AVO response into three fundamental components: intercept (A), gradient (B), and curvature (C). Instead of interpreting raw amplitudes, the user learns

Beyond basic AVO, the Hampson–Russell tutorial also demystifies and simultaneous inversion. The tutorial cleverly frames impedance not just as a product of density and velocity, but as a function of angle. By inverting the near and far angle stacks simultaneously, the user can solve for P-impedance, S-impedance, and density.

The central thesis of the Hampson–Russell philosophy is that "seismic data without well control is merely geomorphology." The tutorial emphasizes that AVO attributes are not absolute physical constants but relative measurements that must be calibrated. The practical exercises guide the user through a process of log editing and petrophysical analysis—calculating volume of shale (Vshale), porosity, and water saturation.