Among the most under-covered U.S. environmental news of the moment must surely be the massive, uncontrolled leak of methane from a natural gas utility’s storage site outside Los Angeles.
Raise your hands if you’ve heard of the Aliso Canyon methane plume … ? Right. I didn’t think so.
Here is a fossil-fuel foulup that practically begs comparison to British Petroleum’s exploding Deepwater Horizon rig in the Gulf of Mexico:
Last Oct. 23, a leak was detected at a Southern California Gas Co. storage well in a community known as Porter Ranch. Storage wells work like production wells in reverse: Natural gas brought in by pipeline from active gas fields is pumped underground into voids left, in this case, by oil wells that ran dry in the 1970s.
The gas travels down through a 7-inch pipe, installed 61 years ago, which is surrounded by a cement casing. And it travels a long way – 8,748 feet, according to an excellent and disturbing explainer by the Los Angeles Times’s Thomas Curwen, published last Saturday:
SoCal Gas tried to plug the well the day after discovering the leak by injecting it with brine and mud, a mixture of water, potassium chloride and bentonite clay. … But approximately 470 feet down, the injections were blocked by an ice plug formed by the bonding of water molecules and methane.
Boots & Coots Services, a Texas company that specializes in well blowouts, recommended dissolving the plug by injecting the well with ethylene glycol, antifreeze. … The ethylene glycol was applied through special tubing that arrived Nov. 1 from a drilling platform off the coast of Louisiana. It worked.
With the ice barrier out of the way, crews resumed injections from the wellhead into the pipes. But the pressure of the escaping gas, measured on average at 2,700 pounds per square inch, was greater than the pressure of the thick cocktail being pushed down. After seven attempts … engineers began to worry that if they pushed too hard with the mud cocktail, they might rupture the pipes, causing an even greater leak.
SoCal Gas decided to drill two relief wells to intersect SS-25 at its juncture with the capstone. The new wells would feature larger and less obstructed piping for the insertion of the brine and mud. The drawback is that the drilling will take months.
A potent greenhouse gas
Methane that rises into Earth’s atmosphere is more than 80 times as potent as carbon dioxide at creating the heat-trapping greenhouse effect that is changing our planetary climate. However, it loses strength after 20 years, while CO2’s impact is longer-lived.
According to the Environmental Defense Fund, which has been striving to call more attention to methane’s role as a driver of perhaps one-quarter of global warming overall, the SoCal Gas leak at peak was delivering the globe-warming equivalent of 7 million additional cars per day. EDF based its calculations on data from the U.S. Environmental Protection Agency, the U.S. Energy Information Agency, the California Air Resources Board and the Intergovernmental Panel on Climate Change’s 5th Assessment.
The leak has been slowed by about half since then; as of Wednesday, the Times took a different approach to social math than EDF and calculated that the well “is releasing as much greenhouse gas per month as 210,000 cars do in a year.”
It has also forced the relocation to temporary housing of 1,700 families sickened by the plume (their nosebleeds, headaches and nausea are attributed primarily to sulfur-smelling additives rather than the methane itself) and 1,000 more are seeking the same assistance. Classrooms at two nearby schools have been emptied into portable facilities elsewhere.
And according to the Los Angeles Daily News, SoCal Gas this week has been installing fine-mesh pads and netting around the wellhead to capture a mist of brine and oil droplets stirred up by winds at the site, which had been drifting into nearby neighborhoods.
On Wednesday, Gov. Jerry Brown declared a state of emergency, directing California agencies to take certain actions and coordinate efforts.
Because methane is as undetectable to human eye as to the nose – and because SoCal’s well didn’t blow up or catch fire – this mishap isn’t a subject for dramatic video coverage of the kind that attended BP’s blowout in the Gulf.
Infrared photography by EDF, shown above, inspired a staff-written blog on Christmas Eve in the Washington Post, which had previously relied on wire stories, as the New York Times continues to do. The news pages of our state’s leading outlet, the Strib, published a single paragraph on Nov. 15, so far as I can discern.
But at 77,000 metric tons and counting, the leaking well remains the single largest point source of greenhouse gas emissions in California and, according to state officials, the largest natural gas leak known to have occurred anywhere.
And its impacts are anything but local.
A weak inspection system
Although some news accounts have suggested that the leak might have been caused by a mild earthquake or other underground movement, experts seem to think that unlikely. After all, the facility came through the big Northridge quake of 1994 without incident.
It also passed inspection in October 2014, which demonstrates that inspectors can’t find a failing pipe before it fails completely.
This is a point that got some emphasis in Switchboard, the staff blog of the Natural Resources Defense Council. After presenting her own social math on the magnitude of the leak to date – equivalent to the yearly GHG emissions of 480,000 passenger vehicles – Briana Mordick wrote that the incident underlines weaknesses in California’s Underground Injection Control program:
This is the same program under which thousands of wells are improperly injecting oil and gas wastewater and other fluids into federally protected drinking water aquifers. And it’s the same program plagued by systemic problems including poor recordkeeping, inadequate staffing, and failure of regulators to perform crucial, required tests to ensure that injection wells are mechanically sound.
The failed well is also quite old. Originally drilled in 1953 as an oil production well, it was converted to a gas storage well in 1973 – before the UIC program even existed. Well construction practices have evolved significantly in that time, but the well has not been updated.
It’s possible that the outdated construction — in particular the lack of cement behind the piece of casing that failed — caused or contributed to the leak. Regulators also reported that a safety valve near the bottom of the well broke in 1979 and was never fixed. If the valve was operational, it may have been easier to stop the leak. …
The well’s construction wasn’t updated and the valve wasn’t fixed because neither safety measure was required. In fact, California’s UIC rules don’t include any standards for well construction. None.
If a brand new gas injection well is drilled today, there is nothing in the rules to prevent it from being built exactly the same way as the [leaking] Standard Sesnon 25. And tests used to ensure that wells are in good condition, called mechanical integrity tests, have to be performed only once every five years.
The likelihood of Standard Sesnon 25 being plugged anytime soon appear slim. State and company officials told the Times’s Curwen that pressure in the pipe must be reduced from 2,700 pounds per square inch to somewhere in 1,000-1,200 range.
The only way to do this is to drill a relief well that angles toward the leaking pipe, then runs parallel to it for 6,000 before connecting to it at the “capstone” atop the gas-filled storage vault, nearly 8,800 feet below ground.
One official told Curwen that “trying to intercept the 7-inch pipe at a depth of a mile and a half ‘is a little like trying to hit a quarter-inch target from the distance of a football field.’ ”
Through rock.
