Flex Trend, Gulf of Mexico
- Flex Trend, Gulf of Mexico
- 2018 - 2020
- Survey type
- Conventional and OBC
- Survey Size
- 30 000 sq. km
- Data Deliverables
- Broadband Kirchhoff and RTM
30 000 sq. km of Flex Vision data is being reprocessed to provide a high-quality broadband depth dataset to solve the imaging challenges across the Flex Trend. The dataset comprises a series of 3D streamer surveys, acquired before much of the exploration and production infrastructure was in place, as well as several post-infrastructure ocean-bottom cable surveys. Together, these form a unique contiguous dataset along the shelf break of the Northern Gulf of Mexico. 18 000 sq. km of rejuvenated data (solid orange) is available now.
Due to substantial oilfield infrastructure, new seismic acquisition is difficult and expensive, so rejuvenation of legacy seismic data is a more cost effective solution. To exploit nearfield supra-salt reserves, high-resolution seismic images are needed that accurately position existing and new plays. Prolonging the life of subsalt fields, such as Mahogany and Hickory, is only possible by improving reservoir models and discovering deeper prospects from superior seismic imaging such as that offered by Flex Vision.
- Broadband reprocessed
- Shallow water demultiple using SWIM
- Velocity model building
- PGS FWI and hyperTomo
- Frequency range for FWI
- 4-9 Hz
- Salt Modeling
- Geologically driven to improve imaging
- Full bandwidth Kirchhoff, 35Hz RTM and structural RTM
Flex Vision rejuvenation improves frequency content, removes complex multiples, builds a data driven and accurate sediment velocity model, solves complex salt geometries and recovers subsalt events in the associated low illumination areas. The top salt structural depth map shown above is of Neogene Roho basins (purple - deep, red - shallow) and their major kinematic directions (arrows). The modern broadband reprocessing and innovative concepts of salt model building are implemented to significantly improve the imaging of potential reservoir sequences trapped either against salt flanks and overhangs or in subsalt settings of primary mini basins.
FWI and Broadband Kirchhoff Migration Reveals Shallow Section
Data driven FWI velocity model building in the overburden combined with broadband Kirchhoff migration accurately images the shallow section. Shallow play fairways and seismic facies are more interpretable, with better resolution of faults and stratigraphy.
Innovative Concepts for Salt Model Building Enable Better Understanding of Salt Geometry
Utilizing the Roho basin concept during salt scenario testing, a velocity model was generated with substantially less salt compared with the legacy data, resulting in an improved subsalt image. Subsalt velocities were calibrated using well logs and show superior ties. Comparison of legacy Wave Equation depth Migration (WEM) with the new Flex Vision RTM image shows dramatic uplift in image quality in the deep section.
Flex Vision delivers a comprehensive and geologically conformable dataset in complex salt architecture. The high frequency, AVO compliant, Q-Kirchhoff is key to demonstrating prospectivity in the shallow play fairways and fields. A 35 Hz RTM volume images the Miocene play fairways and potential in the Lower Tertiary. A structural RTM is available that enables mapping of sediments terminating against salt walls and the structure of the section below 40 000 ft (12 000 m), giving regional context and broad structural and depositional framework understanding. Depositional systems transit this seamless 3D volume from north to south into the prolific deep water of the Gulf of Mexico. Flex Vision will be instrumental in improving industry understanding of these systems and giving explorers an edge over their competitors.
Improved and Accurate Imaging of Known Fields
The FWI driven anisotropic velocity field in the shallow section combined with the improved salt velocity model has accurately positioned reflectors below and against salt bodies. This comparison of legacy WEM with Flex Vision RTM shows repositioning and improved imaging of known oil accumulations within the yellow ellipses.
Structural RTM Provides a Reliable Deep Image
Comparison of legacy WEM with Flex Vision RTM illustrating how the new product allows mapping of Paleogene and older systems down to 40 000 ft.