Looking to modernize its Cartagena refinery in Colombia, Ecopetrol's (NYSE:EC) board of directors has approved spending more than half a billion additional dollars this year on an upgrade. The full project is estimated to cost nearly $6.5 billion.

The project is nearing completion and is more than 80% done with the work pace having doubled this year compared to last year, according to the company. Ecopetrol says the Cartagena project is essential to Colombian energy security and is expected to boost the development of the Colombian Caribbean Coast region as well as the local manufacturing sector. The Cartagena refinery produces propylene, gasoline and naphtha, diesel, fuel oil, and liquefied petroleum gas.

Ecopetrol is Colombia's largest integrated oil and gas company, accounting  for 60% of total production, and it is one of the top 40 oil companies in the world. It's also the fourth-largest oil company in Latin America.