Mexican state oil company Pemex's first well in the deepwater Perdido area just south of the US maritime border will now be the Trion-1 well, which it will drill using the Bicentenario rig, upstream regulator CNH's president, Juan Carlos Zepeda, told BNamericas.
Pemex decided Trion-1 presents a more attractive opportunity, Zepeda added, citing the first component of an economic evaluation Pemex submitted to CNH for review. Pemex has not yet submitted detailed information on Trion-1.
The company intended for the West Pegasus rig to drill its first Perdido well, Maximino-1, until roughly one month ago when it changed plans to drill the Supremus-1 well with the same rig. Two weeks ago, the NOC modified plans again, and will now start exploration of Perdido with Trion-1.
Pemex has invested 4.5bn pesos (US$342mn) from 2007-2011 in Perdido as a means to "reduce geological risk and give greater volumetric and economic certainty to this project," according to text Pemex provided to BNamericas upon request for more information. Investment includes acquisition of 5,000km 2D seismic and 20,000km2 3D seismic data, the result of which was the doubling of prospective resources to 8Bboe and modification of the drilling program.
"It is important to mention that in the international practice, [exploration] is a dynamic process that is modified as a function of the results of geologic and geophysical studies, maximizing at all times the economic value of investments," according to the note from Pemex.
The Bicentenario semi-submersible rig will drill Trion-1 in 2,590m water depth, and Pemex will evaluate its Oligocene and Eocene plays. Pemex is renting Bicentenario from consortium Industrial Perforadora de Campeche (IPC) and Grupo R Exploración Marina (Gremsa) under a five-year contract.
Supremus-1 will be the first well Pemex drills with the West Pegasus semi-submersible, which the NOC has under contract from offshore driller Seadrill's affiliate Sea Dragon de México. Supremus-1 will be located in 2,900m water depths and Pemex will explore its Oligocene play. Once the well is completed, West Pegasus will drill the nearby Maximino-1 well to evaluate its Eocene and Paleocene plays.
Pemex was expected to begin drilling of Perdido in 2011, but delayed arrival of the Bicentenario semi-submersible rig and concerns prompted by the Deepwater Horizon accident in the US pushed back the start of exploration.
Prior to modification of expected prospective hydrocarbons resources from Perdido, Pemex said it believed the entire Mexican deepwater Gulf of Mexico holds 29.5Bboe prospective resources, more than half the country's total 50.3Bboe, and that deepwater thus represents the company's best long-term hope for sustaining oil production. Output has been falling since 2004 due to the natural decline of the giant Cantarell field, though has nearly stabilized at some 2.55Mb/d.
CNH intended to release its report regarding the Perdido area in April, but decided to delay release in light of Pemex's modified drilling plans so as to incorporate Supremus-1 and Trion-1 into its evaluation.
"There has been little lack of definition by Pemex, but they are in the process of submitting the information to us. Hopefully they don't change their decision about what they want to drill and, with that, we can release our review of the [Perdido] project," Zepeda said.