The top crude oil trading companies in Dubai, UAE, included both national oil companies and international trading firms. These companies are involved in various aspects of the crude oil trading business, including exploration, production, refining, and marketing. Here are some of the prominent ones:

1. Emirates National Oil Company (ENOC): ENOC is one of the leading integrated oil and gas groups in the Middle East. It operates in upstream, midstream, and downstream segments, including crude oil trading, refining, and marketing.

2. Dubai Petroleum Establishment (DPE): DPE is another major player in the crude oil trading sector in Dubai. It is responsible for the exploration and production of oil and gas in Dubai's offshore fields.

3. Vitol Group: Vitol is one of the largest independent energy trading companies globally, and it has a significant presence in the Middle East, including Dubai. The company engages in the trading, transportation, and distribution of crude oil and other energy products.

4. Trafigura Group: Trafigura is a multinational commodity trading company with operations across the globe. It has a strong presence in the Middle East and engages in crude oil trading, shipping, and logistics.

5. Glencore: Glencore is another major international commodity trading and mining company. It has a presence in Dubai and is involved in the trading of crude oil and other energy products.

6. Mercuria Energy Group: Mercuria is a Swiss-based energy and commodity trading company with offices in Dubai. It trades in various energy products, including crude oil, and operates across the entire value chain.

7. Gunvor Group: Gunvor is a global commodity trading company with a focus on crude oil, refined petroleum products, and other energy commodities. It has a presence in Dubai and engages in trading activities in the region.

These companies are among the key players in the crude oil trading sector in Dubai, contributing significantly to the region's energy market dynamics. However, please note that the landscape may have evolved since my last update, so I recommend conducting further research for the most current information.