Engineers in a Houston command center and specialists miles out in the Gulf of Mexico worked Wednesday to control a leaking, decades-old offshore well.
The Energy Resource Technology well, located 75 miles south of Port Fourchon, La., has been leaking a briny mix of gas, light condensate and seawater since Monday morning.
Late Wednesday, workers were preparing to begin pumping drilling mud into the well, the first stage in an operation to kill it permanently, 15 years after it last produced gas commercially and four decades after it was drilled.
For much of the day, they were waiting for proof that gas at the platform the well serves had dropped to safe levels so that workers could board the facility. In the meantime, federal regulators and well control specialists waited at a neighboring platform.
“All the equipment necessary to do it is on site,” said David Blackmon, a spokesman for Energy Resource Technology, a newly acquired subsidiary of Houston-based Talos Energy.
The Bureau of Safety and Environmental Enforcement, which regulates offshore energy activity, gave approval for the control operation late Wednesday. The bureau said it approved the movement of pumping equipment to a nearby, connected platform, and the mud-pumping operation after a site safety assessment.
All of the platform work will be conducted about 70 feet above the surface of the water.
Aerial examinations of the site concluded that a light rainbow sheen — estimated at four miles long on Tuesday — had decreased slightly in size, probably because of natural evaporation of the gas.
According to the safety bureau, ERT believes that approximately 3.6 barrels of light condensate is being discharged every 24 hours, based on the size of that sheen.
Unlike spilled oil, some of which may have to be contained and sopped up to prevent environmental damage, leaked gas evaporates naturally over time.
Talos acquired Energy Resource Technology earlier this year as part of a $610 million deal to buy the firm from Helix. In the deal, Talos took over a portfolio of Gulf assets, including new exploration wells as well as older facilities.
The leaking well was decidedly in the latter category. It taps into a field that was developed in the 1970s. It last produced in 1998 and company officials said what was coming out of it then was mostly water at a low-flowing pressure of 175 pounds per square inch.
Talos was in the process of permanently plugging and abandoning the well — as part of an approved idle iron program for decommissioning old equipment — when the leak began.
The Coast Guard and the Bureau of Safety and Environmental Enforcement are overseeing Talos’ response and will conduct an investigation of the incident. But Talos president Timothy Duncan speculated that the age of tubing at the well may have contributed to the episode.
Two other wells at the platform were producing at the time and have been shut-in, federal officials said.
There have been serious incidents at other Energy Resource Technology facilities in the Gulf, including a fatal crane accident at an offshore production facility operated by the company in August 2011.
The Bureau of Safety and Environmental Enforcement faulted the company for failing to maintain equipment in a safe condition; problems included severely corroded, 4-year-old boom hoist wire rope. Critical corrosion and lubrication issues had gone undetected during a contractor’s annual inspection six months before the crane accident, and workers on the site failed to conduct an inspection before the crane was used, the safety bureau said.
The leaking well is located in Ship Shoal block 225 in 146 feet of water. Southern Production and Refining Co. first drilled the well in 1973, but for years it was operated by SONAT Exploration Co.
Although the most recent leak began on Monday, ERT workers first had problems a day earlier. After the initial loss of well control, the company believed the well had been secured on Sunday, the safety bureau said.
Federal records indicate that Energy Resource Technology’s working interest partners in the well include Noble Energy Inc. and Fidelity Exploration and Production Co.