BHP on Wednesday approved spending of close to $956 million for two Gulf of Mexico (GOM) expansion projects, one in U.S. deepwater and the other in Mexico waters.

In the first project, the board OK’d $696 million for its share of funding to develop the BP plc-led Atlantis Phase 3 project. BP sanctioned the expansion in January and plans to spend $1.3 billion for its share of the project. BHP holds a 44% stake, while BP operates and has a 56% interest.

Phase 3, about 130 miles off the Louisiana coast, is a subsea tieback that would add eight production wells that would be drilled and completed to access infill resource opportunities.

“The Atlantis Phase 3 project provides a competitive opportunity to deliver on our strategy to grow resources in Tier 1 conventional deepwater assets,” said President Steve Pastor, who runs petroleum operations. “The project will further expand the Atlantis field and will provide cost-efficient, near term volumes.”

The subsea tieback would take advantage of existing infrastructure, production ullage and marketing agreements.

First production from the third phase of Atlantis is expected in 2020, increasing estimated production by 38,000 boe/d gross at its peak.

BHP also plans to spend $256 million in funding to drill an additional appraisal well (3DEL) and perform further studies in the Trion field in Mexico to further delineate the scale and characterization of the resource.

BHP captured ownership of the field in 2016 as the first deepwater partner ever for Mexico’s state-owned Petroleos Mexicanos, aka Pemex. In the bidding round, BHP, with a 60% stake, won the right to explore jointly with Pemex two blocks in the prolific Perdido Fold Belt.

Trion has gross recoverable resources estimated at 485 million boe. The Trion 1 discovery well in 2012 at the time was considered one of the top 10 discoveries in the entire GOM.

The primary objectives of the 3DEL appraisal well and studies are to confirm the volume and composition of hydrocarbons near the crest of the Trion structure, and study the viability of development of the Trion field. The approved funds are within the forecast BHP exploration and appraisal expenditure budget.

“A further appraisal well at Trion, following the recent encouraging results at the 2DEL appraisal well, reduces investment risk and adds value to this project,” Pastor said. “If Trion is determined to be commercial, these funds will also provide an option to potentially accelerate development of Trion.”

The appraisal well is expected to be drilled in the second half of the year.