It's a regional and financial hub city like New York/London and that's where the money is coming from now. I don't think Dubai has had any significant oil revenue for quite some time.
"Although the United Arab Emirates is becoming less dependent on natural resources as a source of revenue, petroleum and natural gas exports still play an important role in the economy, especially in Abu Dhabi. A massive construction boom, an expanding manufacturing base, and a thriving services sector are helping the UAE diversify its economy. Nationwide, there is currently $350 billion worth of active construction projects."