1. Saudi Arabia

The Kingdom of Saudi Arabia is expected to invest around $149bn (AED547bn) over the next five years on energy projects. This is more than any other country in the Middle East and North Africa (MENA) region, according to the Arab Petroleum Investments Corporation (APICORP).

Efforts to diversify the economy are underway, but the country is still expected to pump billions of dollars into projects to boost upstream oil initiatives.

Plans to develop its gas sector in order to make it a greater part of the country's burgeoning energy mix are also set to get underway. So too are big-money investments in petrochemical projects.

Two major projects currently planned in Saudi Arabia are the world’s largest oil-to-chemical plant in Jubail, eastern Saudi, and the Yanbu integrated refinery and petrochemicals complex, which will have a capacity of 400,000 barrels per day.