As the 23rd World Petroleum Congress got underway Sunday and Monday in Houston, children flag bearers and energy leaders took turns on the stage and attendees enjoyed face-to-face interactions and photo-frame moments.

Chief executives of oil and gas giants from the US, Europe and Middle East shared the stage Monday, along with the US deputy energy secretary and host city Houston's mayor.

Many masked delegates applauded them, and attendees snapped and shared photos on the exhibition floor.

Here is a glimpse into Sunday's Opening Ceremony, Monday's Congress speeches and the exhibition hall.