Study finds ultra-emission methane event at top Mexican O&G asset

A 17-day “ultra-emission event” in December 2021 at one of Mexico’s most important oil and gas assets released an estimated 40,000t of methane into the atmosphere, according to a study highlighted by the European Space Agency (ESA) on Thursday.

The study was published in scientific journal Environmental Science and Technology Letters and led by scientists from Universitat Politècnica de València, using data from Maxar’s WorldView-3 satellite. The researchers tracked the Zaap field in the Gulf of Mexico, part of the Ku-Maloob-Zaap (KMZ) platform cluster, off the coast of Tabasco state in the Bay of Campeche.

According to hydrocarbons regulator CNH, the Zaap field produced crude at an average of 241,000b/d in April, compared to 1.61Mb/d (million barrels per day) combined national production in the month. It is among the largest and most important assets controlled by national oil company Pemex’s E&P unit PEP.

In a statement, the ESA said the study was exceptional in overcoming the observational barrier for tracking methane flaring in open seas, complicated by the reflective nature of seawater, compared to the contrast soil provides in tracking onshore flaring.

The space agency also said the amount of methane emissions during the event was equivalent to around 3% of Mexico’s annual oil and gas emissions, “and this single event would have a similar magnitude to the entire regional annual emissions from Mexico’s offshore region.”

According to the study, the KMZ area was selected in the first run with the experimental methodology based on recent offshore emissions analyses, while “this is the Zaap offshore field area which is responsible for roughly 20% of Mexican oil offshore production.”

The flaring event

Christian Retscher, the study’s lead author, did not immediately respond to a request for comment by BNamericas on further reasons why the key location was selected.

The ESA, however, quoted Retscher as saying, “the study demonstrates the growing capabilities to detect methane emissions from space at a very high spatial resolution,” highlighting the growing inability for individual upstream players to hide such events in the face of increasingly sophisticated technology.