We demonstrate the impact of using full-waveform inversion velocity-model building to improve the seismic image in an especially challenged salt environment in the Gulf of Mexico. This was BP’s first trial using full- waveform inversion for imaging “EWATS” (full-azimuth ultralong-offset) streamer data, which posed a unique challenge due to the combination of difficult geology and slightly inferior low-frequency and long-offset content compared with OBN data. Specifically, a large sediment suture between two saltbodies in our study area proved problematic for imaging. We carried out various scenario tests including: 1) the use of a “legacy FWI” algorithm combined with manual salt interpretation to update our legacy velocity model, and 2) using a new FWI algorithm without manual interpretation to update multiple starting models. Results demonstrate imaging improvements that impacted a recent exploration and appraisal drilling campaign. The improved image and velocity model resulting from FWI helped to resolve a shallow carapace section and intrasalt sediment inclusions which influenced operational decisions during real-time drilling. Additionally, the subsalt structural image was enhanced which improved resource estimations and will likely impact future appraisal and development well locations.
Presentation Date: Tuesday, October 13, 2020
Session Start Time: 1:50 PM
Presentation Time: 4:20 PM
Location: 361F
Presentation Type: Oral
