Flex Trend, Gulf of Mexico

One Dataset for Both Nearfield and Regional Exploration

Flex Trend, Gulf of Mexico

Flex Vision provides tailored images using Kirchhoff for shallower targets, delivering broad frequency content and reliable amplitudes, and RTM for regional understanding and unlocking deeper plays.

Location

Location
Flex Trend, Gulf of Mexico
Reprocessed
2018 - 2021
Survey type
Conventional and OBC
Survey Size
17 000 sq. km
Data Deliverables
Broadband Kirchhoff and RTM

17 000 sq. km of Flex Vision data provides 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. 

Challenge

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.

Solution

Data
Broadband reprocessed
Processing
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
Migration
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

Legacy Kirchhoff
Flex Vision Kirchhoff

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

Legacy WEM
Flex Vision RTM

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.

Results

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

Legacy WEM
Flex Vision RTM

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

Legacy WEM
Flex Vision RTM

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.

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