Reverse Time Migration (RTM)

Steeply dipping traps can be extremely prolific and capable of being drained with relatively few high-rate wells. However, current migration methods face limitations in the presence of complex, steeply dipping reflectors such as those found on salt flanks. Reverse time migration (RTM) overcomes these constraints, enabling structures with dips greater than 90 degrees to be properly imaged.

Enhanced RTM Approach by GXT

Although RTM is not a new concept, its application has been limited due to the algorithms' power needs, cost, and turnaround time. We have enhanced the RTM approach to improve its efficiency. Our RTM method was developed by matching highly sophisticated algorithms with currently available computational power, resulting in an improved and economical solution for imaging complex subsalt prospects. We have applied the technique extensively worldwide, including the Gulf of Mexico, North Sea and offshore West Africa.

Wide Azimuth Reverse Time Migration

Wide azimuth surveys have acquisition geometries that are ideally suited for RTM. GXT's RTM has the ability to image complex raypaths, including prism waves (double-bounce events), which may be a key attribute in resolving target prospects and the positions of those prospects. In addition, our RTM code supports VTI and TTI anisotropy.

Benefits of GXT's RTM Offering

• Provides an alternative approach to migration with fewer compromises
• Images both the steep sides of salt bodies and underneath them, regardless of the dip and rugosity at the top
• Reduces project turnaround time
• Yields more accurate models that significantly improve the final sub-salt image