eGWM Depth Migration
Wave equation migration (WEM) overcomes the limitations of ray-based methods (e.g. Kirchhoff) which struggle to image structure beneath complex overburden. However, this comes at the expense of increased run-time, cost, and energy consumption. Future migrations must combine the advantages of WEM whilst improving efficiency.
Historic wave-based migrations (WEM) suffer from dip limitations and multi-mode contamination as a result of attempting to model all wave modes. Reverse Time Migration (RTM) is a commonly used WEM migration. As an acoustic method, RTM has inherent problems: images are low frequency, amplitudes are not preserved, offset gathers cannot be produced cost-effectively and are not suitable for elastic inversion.
eGWM is the next generation of WEM and provides a multi-path solution capable of imaging steep dips whilst intuitively attenuating noise and multiple energy. eGWM fully supports amplitude integrity, and is unique in that it simultaneously outputs offset and AVA compliant angle gathers - ideal for AVO/AVA studies.
eGWM is positioned to replace all ray-based imaging methods, and at 30 times the efficiency of RTM, eGWM provides a faster and more energy efficient solution than conventional WEM.
Mungo, U.K. North Sea
RTM Runtime 42 DAYS @ 50Hz.
RTM requires a massive run time yet produces steep events lacking correct amplitude and poor response at deep levels.
eGWM Runtime 1 DAY @ 80Hz.
eGWM provides better imaged steep dips, subtle amplitude variations and cleaner events deeper down, after just 1 day.
Gulf of Mexico
In the shallow section, Kirchhoff is unable to resolve the complexity of the structure.
eGWM easily images complex faulting (centre), individual layers, and channelling (lower right).
Kirchhoff fails to effectively image the base of the salt and layers below.
eGWM greatly improves understanding of the salt geometry and layers beneath the salt. Unlike other WEM, there is no mode converted energy corrupting the image.
Our P&I Services
Processing from field tapes
eMULT proprietary de-multiple
eBAND proprietary de-ghost
Land and Marine
GRT true amplitude, AVA compliant
eGWM ultra-fast wave equation migration
Traditional migrations, e.g RTM, Kirchhoff