Chevron said Thursday it planned to significantly expand production at its St. Malo field in the deepwater Gulf of Mexico.

The fourth phase of its Jack/St. Malo development involves drilling new wells and injecting water into existing wells to churn out more oil and extend the life of the project.

The overall development is expected to produce more than 500 million barrels of oil equivalent over the course of over 30 years, including more than 175 million barrels from this so-called “waterflood project.”

Water injection isn’t used as often in the deepwater Gulf because of the strong initial recovery from wells and the associated costs with the additional water injection.

The initial development costs of the project totaled about $7.5 billion.

“The St. Malo field is a world-class asset that is positioned for highly economic brownfield development,” said Steve Green, Chevron’s president of North American exploration and production. “With our leading technology, experienced workforce and broad portfolio, we’re delivering value in the Gulf of Mexico.”

The new phase will include two new production wells, three new injector wells and additional equipment for the Jack/St. Malo floating production platform. The costs were not disclosed.

Chevron, the third-largest producer in the Gulf of Mexico, owns a 50.1 percent controlling state in the St. Malo field.

Norway-based Equinor owns 21.5 percent, Murphy Oil holds 20 percent, Brazil’s Petrobras has 5 percent, and Exxon Mobil and Italy’s Eni each hold 1.25 percent.

This article first appeared on the Houston Chronicle – an Energy Voice content partner. For more from the Houston Chronicle click here.