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Least-squares Migration (LSM) is an advanced technique that are corrects for overburden effects and inconsistent seismic acquisition, improving the resolution and amplitude balance of migrated images and enabling more informed E&P decision making.

Traditional depth migration techniques (Kirchhoff, Beam, RTM), whilst extremely valuable in modern imaging workflows, produce an inherently blurred representation of Earth reflectivity. Despite numerous steps within the imaging workflow to account for inconsistencies in the acquisition parameters of a project and earth properties of sub-surface reflectors that distort the image (i.e. velocity and attenuation), the most reliable and accurate way to address these inconsistencies is within the migration operator itself.  Least Squares Migration is an advanced process that attempts to understand the errors in the reflectivity model and more appropriately balance the amplitude behavior of sub-surface images.

 Least Squared migration can be used to:

  • Reduce migration artefacts from irregular acquisition
  • Balance amplitudes of reflectors for more reliable geologic interpretation
  • Account for fine discrepancies in acquisition, improving image resolution

At ION we have a comprehensive LSM toolkit that is applicable in a wide range of geological environments and that is suited to all acquisition geometries including Towed Streamer, OBN and Land

In high contrast and complex geological media, sub-surface structures present an illumination challenge for deeper reflectors. While conventional RTM addresses the structural component of complex geological imaging, our LSRTM corrects for this further and provides more reliable amplitude information of critical target reflectors.

Specification:

  • Applicable to all major acquisition geometries
  • Gather output options include shot-offset, sub-surface offset, surface offset
  • High resolution output in excess of 70Hz commercially viable

In simple-complex, but relatively low contrast geologic media, Kirchhoff migration provides an extremely reliable image for interpretation, despite this least squares migration can improve further on the image, accounting for acquisition discrepancies.

Specification

  • Applicable to all major acquisition geometries
  • Gather output options include shot-offset, sub-surface offset, surface offset
  • High resolution output in excess of 70Hz commercially viable