The Ol' Ball and Chain vs. the Mud Volcano

February 27, 2007

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A mud volcano in Indonesia has spewed the equivalent of a million barrels of mud a day for nine months, leaving more than 10,000 people displaced and scores of factories shut down. As attempts to alleviate the problem have so far failed, the government's new plan will take balls of concrete — steel chains of it, in fact.

Indonesian residents have had some tragically bad luck with natural disasters these past few years. The December 2004 undersea earthquake, known by the scientific community as the Sumatra-Andaman earthquake, triggered a series of devastating tsunamis that spread throughout the Indian Ocean, killing large numbers of people and inundating coastal communities across South and Southeast Asia.

Then last May, a destructive mud volcano on East Java, in the middle of a rice paddy in the village of Porong, erupted, spewing out up to 126,000 cubic meters of mud a day since then, flooding an area of more than 4 square kilometers. Some 10,000 people have been left homeless and 20-25 factories have closed. Another 200,000 homes could be at risk if the mudflow combines with the rainy season — which recently began — and weakens dams to flood more land. The vast scale of the flow is expected to cause ground subsidence, with a "more dramatic collapse" forming a crater around the volcano's mouth, according to the UK's Guardian.

Attempts to alleviate the problem by drilling relief wells or channeling the mud into a nearby river have thus far failed.

As such, in late January a government team of geophysicists, scientists and engineers tackling the disaster approved a plan to drop chains of concrete balls into the mouth of the mud volcano in East Java to stem its flow.

Under the plan to choke the mudflow, 375 clusters will be lowered into a 50-meter-wide hole from where the mud has been gushing, with each chained cluster consisting of four balls, for a total of 1,500 concrete balls to be dropped into the volcano's mouth. Each cluster of 20-40-centimeter diameter balls weighs 300-400 kilograms, and the balls themselves will be modified to maximize their friction with the mud.

The chains will be dropped into the mouth of the eruption from a bridge built across the crater and will sink into the conduit that has been feeding the hot mud to the surface. The team is aiming to go 100 meters down, but the deeper the better.

The journal Nature reports:

The goal is to make the channel smaller — not plugging it altogether but, according to a model built by the team, narrowing it enough to slow the mud's rise and so decrease its flow rate by up to three-quarters. Forced to go around the ball and chains, the mud will give up some of its energy to friction, vibration and rotation.

An Indonesian worker walks among concrete balls that will be used to help stem a massive mudflow that has been spewing out millions of barrels of mud for the past nine months, pic via The Associated Press.jpg Simply put, it will exhaust and kill the mud "softly."

The US$440,000 project was dreamt up by three geophysicists at the Bandung Institute of Technology. In mid-January, the geophysicists met with scientists and engineers from the government and PT Lapindo Brantas, the oil drilling company that some have accused of having caused the disaster.

Research published in the scientific journal GSA Today last month shows that the mud volcano "was probably triggered by commercial drilling." In May, Lapindo engineers drove their drills to a depth of almost 3,000 meters (9,840 feet), into what is known as the "Kunjung formation," where they hoped to encounter oil and, more important, natural gas. (Image credit: AP Photo/Trisnadi, via Discovery News)

What happened then may or may not have been a natural phenomenon.

National Geographic reports:

A team of British researchers says the deadly upwelling began when an exploratory gas well punched through a layer of rock 9,300 feet (2,800 meters) below the surface, allowing hot, high-pressure water to escape. The water carried mud to the surface … The mud volcano is similar to a gusher or blowout, which occurs in oil drilling when oil or gas squirt to the surface, the team says. This upwelling, however, spews out a volume of mud equivalent to a dozen Olympic swimming pools each day.

"The British-based scientists [in the report published in GSA Today] believe drilling at a depth of more than 2 kilometers (1.3 miles) ruptured a highly pressurized pocket of hot gas and water which created fissures in a bed of porous limestone," reports The Associated Press (via International Herald Tribune).

Wherever the fault lies — nature or drilling — the ongoing disaster now relies on this new ball-and-chain plan.

Yet other physicists say they have never heard of such an approach, and they question its likely effectiveness. Richard Swarbrick, managing director of Durham, UK-based consultancy firm GeoPressure Technology, for one, says that cutting the size of the channel "could very well reduce the mudflow." And although forcing the mud to take a "tortuous" path around the balls would also slow it down, he points out that reducing the size of the channel is likely to increase the pressure, just like squeezing the end of a hose.

"I would predict that the mud would probably exit at the other holes, or farther along," Nature reports Swarbrick as having said. This would simply transfer the problem elsewhere. "The mud will find another way out," Swarbrick says.

The Indonesian engineers have already hit snags. Last Saturday, they were forced to abandon the attempt to plug the gushing mud volcano when a steel cable hoisting the balls broke, according to The Associated Press over the weekend.

On Monday, however, the Indonesian engineers successfully dropped four clusters of the chained concrete balls (16 balls total) into the fissure. Authorities will monitor the effects of the balls before dropping more throughout today.

To date, alternative efforts to stem the flow by drilling relief wells or draining the mud into a nearby river have had little or no effect. In fact, in November a natural gas pipeline cracked under the weight of a dam built to channel the mud to the sea, triggering a powerful explosion that killed 13 people and injured a dozen others. So far, the mud has swamped an area of more than four square kilometers and is increasing by the day.

In addition to the 13 deaths caused by the catastrophe, nearly 25 factories and four villages have been inundated, making it unlikely that the 11,000 inhabitants will ever return home.

Resources

Volcano gets choke chains to slow mud by David Cyranoski Nature, Jan. 31, 2007

Drilling for gas 'caused deluge' from Java mud volcano by Ian MacKinnon Guardian Unlimited, Jan. 24, 2007

Indonesia delays dropping concrete balls into volcano The Associated Press, Feb. 25, 2007

Indonesia drops chained balls into mud volcano Reuters, Feb. 26, 2007

Eruptions Displace Thousands in Indonesia by Marco Evers Spiegel, Oct. 9, 2006

"Mud Volcano" in Indonesia Caused by Gas Exploration, Study Says by Richard A. Lovett National Geographic News, Jan. 25, 2007

Scientists say Indonesian mud volcano caused by drilling, not natural disaster The Associated Press, Jan. 24, 2007

Indonesian Engineers Plug Crater The Associated Press, Feb. 27, 2007

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