MGIVA is FSI's proprietary velocity analysis system. It combines leading-edge functionality with ease-of-use in the derivation of high-quality velocity fields. Uniquely with FSI software, MGIVA may be licenced by companies engaged in exploration and development of hydrocarbon resources. Principal features include:
Map of all picked and unpicked Velocity/Eta locations: Multi-format Velocities and/or Eta Coefficients displays (contours, circles, etc.). Iso-time / iso-profile levels for map display; incorporation of well velocity information.
An Eta (anisotropy coefficient) Analysis Window: Eta is interpreted on a suite of gathers and NMO performed with a suite of eta values; Changes to the input stacking velocity field are immediately implemented in the eta analysis; The interactive gather is updated after each eta pick; If the user elects to 'pick up' an existing pick, the gather will dynamically update as the user moves the cursor over the eta analysis display.
Iso-velocity/eta Contour Profile: Velocity/eta locations are indicated and locations for analysis can be selected from the contour display; Profiles can be displayed in-line/cross-line; automatically updated after each pick
Semblance Display: Pre-computed stack panel velocity functions displayed; Picking on semblance display or mini-stack panels; interval velocity curve is displayed; neighbouring velocity functions displayed; user alerted to 1st order (peg-leg) multiples; both interactive panels, gathers/stack, immediately reflect changes in velocity picks.
Stack Display of the Velocity Line Indicating Analysis Locations: The Velocity and/or Eta picks are posted on the stack display; The stack can be displayed in multiple formats (colour, wiggle, VA, etc.; Auto-scrolling option to ensure current analysis location always visible.
Suite of Mini-stacks: The mini-stacks suite is generated using percentage variations of the existing velocity field; Picking can be performed on the mini-stack panels or on the semblance display; If picking on semblance display, mini-stack display auto-scrolls ( both vertical/horizontal) to ensure that the current semblance values visible on mini-stacks display.
Interactive Gather Display: The interactive gather is updated after each velocity pick; dynamic update as the user moves the cursor over semblance display; NMO can be performed with 2nd order, 4th order or with higher order with anisotropic (eta, A) coefficients.
AAMOGIVA
FSI’s proprietary AAMOGIVA software performs velocity analysis for azimuthally anisotropic media. AAMOGIVA uses the HTI model for azimuthal anisotropy where the observed variation of velocity with azimuth is elliptical, defined by an azimuth angle, a parameter controlling the time-variant eccentricity of the ellipse, and a velocity. Thus the proper moveout correction can be estimated as a function of source-receiver azimuth. AAMOGIVA gives the geophysicist the ability to simultaneously pick azimuth angle, eccentricity, and velocity from semblance panels. The resulting stack is updated in real time to guide the analysis.