Procesamiento por sobretiempo debido al buzamiento

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Una operación de procesamiento sísmico para corregir el hecho de que, para reflectores con buzamiento, las trazas que componen un registro CMP no tienen un punto de reflejo común.

El procesamiento por sobretiempo por buzamiento genera un registro de punto de reflexión común aparente aplicando convolución a los registros de punto medio común adyacentes, con la característica que el sobretiempo producido con el aumento de la distancia fuente a receptor no depende del ángulo de buzamiento (véase Figura C-9b).

FIG. C-9. Common-midpoint method. (a) In six-fold shooting with 24-geophone groups and the source point moved two group intervals between successive shots; the same subsurface is sampled six times (A⇒23, B⇒21, C⇒19, D⇒17, E⇒15, F⇒13). (b) A reflector that dips does not have a common reflecting point and common-midpoint stacking results in reflection-point smearing unless DMO (q.v.) processing or migration precedes stacking. (c) To achieve a common-reflection point in the case of dip requires unequal surface spacing. (d) A common-source gather is a collection of traces having the same source; (e) common-receiver gather; (f) common-offset gather. (g) If there are horizontal velocity variations, prestack migration is required to form a common-imaging-point gather. Compare Figure C-13. All diagrams assume constant velocity.

DMO effectively corrects for the reflection-point smear that results when dipping reflectors are stacked by the CMP method. After DMO is applied, events with various dips stack with the same velocity.

DMO stands for dip moveout, but it is different from the classical dip moveout that is simply the effect of dip on arrival times.

DMO can be performed in a number of ways, including prestack partial migration[1], time-domain, finite-difference methods (offset continuation)[2], Fourier-domain implementation[3], integral (Kirchhoff) methods[4].

FIG. D-20. DMO. (a) Depth section showing the updip movement of the reflecting point for an offset geophone for constant velocity; , where ; is the dip (Levin, 1971). To avoid reflection point smearing, an offset trace should be gathered with the updip zero-offset trace at a distance , but such a gather is not hyperbolic; the DMO correction makes this gather hyperbolic. (b) A diffraction in location-offset space, a Cheops pyramid, is not a hyperboloid. (c) Applying NMO changes the Cheops pyramid into a saddle-shaped surface. (d) Applying DMO along with NMO yields data that can be stacked without reflection-point smear. (e) NMO corrects for the time delay on an offset trace assuming horizontality, DMO moves the data to the correct zero-offset trace for a dipping reflection, and migration further moves it to its subsurface location.[5]

Velocity-dependent DMO is usually applied after velocity-dependent NMO. Gardner’s DMO [6] applies velocity-independent DMO prior to velocity-dependent NMO. See Figure D-20 and double square-root equation.


  1. Yilmaz, O; Claerbout, J. F (1980). "Partial prestack migration". Geophysics 45 (12): 1753–1779. doi:10.1190/1.1441064.
  2. Bolondi, G; Loinger, E; Rocca, F (1982). "Offset continuation of seismic sections". Geophysical Prospecting 30 (6): 813–828. doi:10.1111/j.1365-2478.1982.tb01340.x.
  3. Hale, Dave (1984). "Dip‐moveout by Fourier transform". Geophysics 49 (6): 741-757. doi:10.1190/1.1441702.
  4. Deregowski, S. M.; Hosken, W. J. (1985). "tutorial: Migration strategy". Geophysical Prospecting 33 (1): 1-33. doi:10.1111/j.1365-2478.1985.tb00419.x.
  5. Deregowski, S. M. (1986). "What is DMO". First Break 4 (7): 7–24. doi:10.3997/1365-2397.1986014.
  6. Forel, David; Gardner, Gerald H. F. (1988). "A three‐dimensional perspective on two‐dimensional dip moveout". Geophysics 53 (5): 604-610. doi:10.1190/1.1442495.

External links

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DMO (dip moveout) processing/es
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