Brent was consistently
less than WTI for the vast majority of the time the export ban was in effect (1975-2010). Your chart shows the impact of fracking, which took off around 2010 and caused a surplus of light/sweet oil in the US. Especially in the TX/OK region (WTI is priced in Cushing, OK).
We could have repurposed our expensive, high complexity refineries to do the simple job of refining light, sweet oil, but that would be stupid. Furthermore, we import more than twice as much crude oil as we export (6m+ bpd vs. <3m bpd). The only reason we're close to neutral overall is we also export almost 3m bpd of NGLs (ethane, propane, etc.) and are a small net exporter of finished products.
Wrong transcript. On March 10
she said VZ was "the largest producer of oil in the world". As I said they're something like 25th. Some reporters gave her a WTF look so she quickly backpedaled to "one of them".