Hampson Russell Tutorial Apr 2026

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

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." hampson russell tutorial

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). It teaches that an AVO anomaly is a

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 key technical innovation taught here is the

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.