Field/project development

Winterfell Tieback Begins Producing to Heidelberg Spar

First three wells of deepwater Gulf of Mexico project expected to jointly produce 22,000 BOE/D to the nearby host facility.

Planned development phases in the Greater Winterfell area.
Source: Kosmos Energy

The deepwater Winterfell development in the Gulf of Mexico has begun production from two wells, partner Kosmos Energy announced 3 July.

In January, Beacon Offshore Energy approved development of the 2021 Winterfell discovery. The project, operated by subsidiary BOE Exploration & Production LLC (BOE), is a subsea tieback to Occidental’s Heidelberg spar in Green Canyon Block 860.

Winterfell is a Miocene-aged field in about 5,400 ft of water located in Green Canyon Blocks 899, 900, 943, 944, 987, and 988.

Following the 2021 discovery, the Winterfell-2 appraisal well evaluated the adjacent fault block northwest of the original Winterfell discovery and tested two horizons that were oil bearing in the Winterfell-1 well, with an exploration tail into a deeper horizon, according to Kosmos. That well discovered about 120 ft of net oil pay in the first and second horizons with better oil saturation and porosity than pre-drill expectations, and the exploration tail discovered an additional oil-bearing horizon in a deeper reservoir, Kosmos said.

Following the successful drilling and completion and subsea hookup of the first two production wells in April 2024, Kosmos said, subsequent work delays pushed first oil beyond the targeted onstream date of second quarter 2024. The first two production wells are now online and ramping up production, the partner said, and a third well that is being drilled is expected online by the end of the third quarter 2024. Together, the three wells are expected to produce 22,000 BOE/D to the Heidelberg spar 13 miles away.

The whole first phase of the subsalt field development calls for five wells to deliver about 100 MMboe with upside from later phases, Kosmos said.

Partners in Winterfell include Beacon Offshore Energy Exploration LLC (35.08%), BOE (0.33%), Kosmos Energy (25.04%), Westlawn GOM Asset 3 Holdco LLC (15%), Red Willow Offshore, LLC (12.5%), Alta Mar Energy (Winterfell) LLC (7.55%), and CSL Exploration LP (4.5%).