Even The Relief Well May Blow Up

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May 19th, 2010 report from Solveclimate.com

Did Deepwater Methane Hydrates Cause the BP Gulf Explosion?

According to the National Academy of Sciences, which published a bullish report on the energy potential of methane hydrates,

"Industry practice is to avoid methane-bearing areas during drilling for conventional oil and gas resources for safety reasons."

Professor Sum explained that because "with oil there is usually gas present," it is possible for methane hydrates to form in the pipe even when not drilling through hydrate-bearing sediments. The pressure and cold of the deepwater create conditions that encourage gas flowing into the pipe to form hydrates, and if the rate of crystallization is rapid enough, the hydrates can clog the pipe.

The cofferdam that BP lowered over the broken pipe gushing oil to contain the spill was almost immediately clogged by methane hydrates, which formed spontaneously. Gas escaping with the oil from the well, when trapped in the steel structure with cold water under great pressure, rapidly accumulated into an ice-like matrix.

Documented Explosive Hazard

In a book about methane hydrates, which Professor Koh co-authored, brief mention is made of a case in which methane hydrates caused a gas pipe to rupture on land, leading to loss of life.

Two workers were attempting to clear a line in which a hydrate plug had formed. The authors say that "the impact of a moving hydrate mass" caused the pipe to fail. The explosion caused a large piece of pipe to strike the foreman, killing him. The book then quotes from the Canadian Association of Petroleum Producers Hydrate Guidelines to describe proper procedures for safely removing a hydrate plug in a pipe on land.

SolveClimate was not able to find more detailed public documentation of this incident in Alberta, but mention is made in an article in a publication of the Oak Ridge National Laboratory, a federal research center associated with the Department of Energy, of a different unspecified incident on a drilling rig.

"Forces from methane hydrate dissociation have been blamed for a damaging shift in a drilling rig's foundation, causing a loss of $100 million," the article reports.

Although public discussion of damage from methane hydrate accidents appears to be minimal, the danger is well-recognized within the industry. Last November, one Halliburton executive gave a presentation before a meeting of the American Association of Drilling Engineers in Houston, titled "Deepwater Cementing Consideration to Prevent Hydrate Destabilization."

It recognizes that the cementing process releases heat which can destabilize methane hydrates, and presents something called Cement System 2 as a solution to the problem. One of the graphs shows that the system doesn't achieve gel strength for four hours.

Yet according to an eyewitness report broadcast on Sunday on 60 Minutes, BP managers made the decision to decrease pressure in the well column by removing drilling mud before the cement had solidified in three plugs Halliburton had poured.

When a surge of gas started shooting up the well, a crucial seal on the blowout preventer at the well head on the ocean floor failed. It had been damaged weeks before and neglected as inconsequential by Transocean managers, according to the CBS news broadcast, even after chunks of rubber emerged from the drilling column on the surface.

According to the Associated Press, the victims of the Deepwater Horizon explosion said the blast occurred right after workers "introduced heat to set the cement seal around the wellhead." It is not known if Halliburton was employing Cement System 2, and testifying before the Senate last week, a Halliburton executive made no mention of methane hydrate hazards associated with cementing in deepwater.

A Promising Substance

Professors Koh and Sum are concerned that a focus on the dangers of methane hydrates in deepwater drilling will obscure their promise as an energy solution of the future. They are conducting research in the laboratory to create methane hydrates synthetically in order to take advantage of their peculiar properties. With their potential to store gas (both natural gas and hydrogen) efficiently within a crystalline structure, hydrogen hydrates could one day offer a potential solution for making fuel cells operate economically. Still at the fundamental stage, their work on storage is not yet complete enough to apply to commercial systems.

At the same time, there is an international competition underway to develop technology to harvest the vast deposits of methane hydrates in the world's oceans. Japan has joined the US and Canada in pursuit of this energy bonanza, motivated by the $23 billion it spends annually to import liquefied natural gas.

According to a Bloomberg News article called "Japan Mines Flammable Ice, Flirts with Environmental Disaster," the Japanese trade ministry is targeting 2016 to start commercial production, even as a Tokyo University scientist warned against causing a massive undersea landslide that could suddenly trigger a massive methane hydrate release.

The U.S. has a research program underway in collaboration with the oil industry, authorized by the Methane Hydrate Research and Development Act of 1999. The National Methane Hydrates R&D Program is housed at the National Energy Technology Laboratory (NETL) of the Department of Energy.

The National Academy of Sciences provided a briefing for Congress last January on the energy potential of methane hydrates based on its report which asserts that "no technical challenges have been identified as insurmountable" in the pursuit of commercial production of methane hydrates. More...

"If pipe in bore hole is perforated, we are in serious trouble"

The evidence is growing stronger and stronger that there is substantial damage beneath the sea floor. Indeed, it appears that BP officials themselves have admitted to such damage. This has enormous impacts on both the amount of oil leaking into the Gulf, and the prospects for quickly stopping the leak this summer. Washington's Blog

Excerpt from Solve Climate.com, May 24th, 2010
By the end of 2008...even industry insiders were starting to acknowledge that the deepwater drilling boom had grown beyond the safety capacity of the oil and gas companies to manage properly. With profits on the line, rig crews were stretched thin and staffed with less experienced operators, as this article from Drilling Contractor acknowledged.

Independent Investigator

The 60-page report which opens the window on these revelations was authored by Dan Zimmerman, an independent environmental investigator of the Northcoast Ocean and River Protection Association (NORPA). He has worked with numerous groups since 1975, especially on pesticide, forestry and salmon habitat issues. The executive director of Californians for Alternatives to Toxics, Patty Clary, told SolveClimate she has worked with Zimmerman for 14 years and called him "a brilliant researcher."

Zimmerman said that he sent his report last September to hundreds of environmental organizations and individuals, but got no response.

"It's become a popular topic now," he said, with attorneys and environmental groups now examining his report.

Yet Zimmerman was more interested in discussing the Gulf oil spill than his report, expressing concern about the condition of the blowout preventer on the sea floor and the pipe in the bore hole. If the pipe in the bore hole has been perforated, he said, a "top kill" being planned by BP may not stop the leak.

"My concern is that cratering has now occurred and a flow path has been established outside the well bore. If this has occurred we are in serious trouble, more than we currently think."

"If there are plumes of gas and oil rising from the sea floor around the pipeline," Zimmerman said, "that would be an indication. They have submersibles. They should be examining the area around the blowout."

His concerns seem well-founded. One of the most complete and factual chronologies of the events leading up to the BP Gulf of Mexico blowout recounts this situation five minutes before gas shot out of the drill column on the surface of the ocean.

Standpipe pressure increased and decreased twice between 21:30 and 21:42 (standpipe pressure generally reflects bottom hole pressure). This, along with a steady increase in mud pit volume, suggests that surges of gas were entering the drilling fluid from a gas column below the wellhead, and outside of the 7-inch production casing. Gas had probably channeled past the inadequate cement job near the bottom of the well and, by now, had reached the seals and pack-offs separating it from the riser at the sea floor.

Failure of a "top kill" — if it doesn't make matters worse — would leave well control experts with only one final known option for stopping the leak in the Gulf: drilling a relief well. The idea is to reach the oil reservoir with a well drilled on a tangent to the original, and seal it closed. But an industry publication published in 2009 indicates that drilling a relief well to 18,000 feet below the sea bed is beyond the edge of the technical capability of well control experts.

The detection tools used to locate the blowout wells have been successfully used for many years. However, there have been very few relief wells drilled deeper than 16,000 ft. A very deep intercept greater than 20,000 ft will be a challenge to any relief well team. If the deep intercept cannot be made, a shallower depth will need to be chosen. This complicates the kill operation as it will not be made close to the reservoir.

Ocean Boiling with Methane
Zimmerman devotes more than ten pages of his report to a partial listing of blowouts caused by drilling into or through methane hydrates. It is a sobering listing that includes photographs and links to disturbing videos, including one that shows a drill room on a platform at the moment a blowout occurs, and another that shows the ocean boiling with methane escaping around a drilling rig.

A longtime environmentalist, Zimmerman sometimes becomes indignant in his report:

GHG release from offshore O&G operations should be thought of as the O&G industries dirty little secret. Massive releases of methane and CO2 have been occurring from these offshore operations for over 45 years, with little concern shown by the O&G industry for the deadly impacts they have generated...

This pattern of extracting first and asking questions later has always been the method of operation for the oil, gas and coal industries. And they are often helped along by politicians and regulatory agencies. More...

Another oil leak from offshore oil platform #23051 in the Gulf

skytruth.org
Routine Gulf Monitoring - Here's Why We Need It
Three days ago we blogged about a possible small, but persistent, leak from offshore oil platform #23051 in the Gulf of Mexico, not far from the ongoing Deepwater Horizon spill. We asked for confirmation from anyone who might happen to be in the vicinity. Ask, and ye shall receive:

Photograph taken 6/5/10 of apparent oil leak in the vicinity of Platform 23051, courtesy J Henry Fair. Semisubmersible drill rig in foreground; workboat at left where the plume originates at the surface. Note a second plume apparently originating from platform in the background at upper right; this may be Platform 23051 (not yet confirmed).

Professional photographer J Henry Fair flew over the site yesterday using the MMS platform location in our blog post, and took photos of what he found. Here are the two he sent us today. There is an obvious plume of oil in the water next to a semisubmersible drill rig. J Henry identified it as the Ocean Saratoga rig (nice picture here), owned by Diamond Offshore.

The May 17 rig status report available on Diamond Offshore's website (which prominently features a photograph of Senator Mary Landrieu, with the caption "Credit where credit is due") shows the Ocean Saratoga is currently under contract to drill for the same company that owns and operates Platform 23051. The platform may be the one visible in the background of the photo above, apparently trailing another oily-looking plume. So it's possible that we've actually discovered two separate leaks or spills in the same vicinity.

A closer look at the semisubmersible rig, work boat, and apparent plume of oil near the location of Platform 23051 in the Gulf of Mexico, taken June 5, 2010. Photo courtesy J Henry Fair.

J Henry described the workboat at the end of the oil plume as "churning the oil" as if to disperse it more quickly. It's unclear from these pictures if the workboat is itself the source of this oil plume, or if indeed it's motoring around where an oil plume is emerging at the ocean surface in an attempt to break it up. In any event, this spill is certainly large enough to require reporting to the Coast Guard.

Other than us - is anybody watching what's going on out there?

This is why we think America needs publicly transparent, routine satellite monitoring wherever we allow offshore oil and gas drilling.

Relief wells: "You have to hit something the size of a dinner plate miles into the earth"

Image via Wikipedia

Drilling relief wells to stop Gulf oil leak poses challenges
Rebecca Mowbray
The Times-Picayune

With the "top kill" declared a failure and BP moving on to less-desirable options to stop its well from continuing to shoot thousands of barrels of oil each day into the Gulf of Mexico, the grim reality set in that the company may be unable to stop the oil until it completes the first of two "relief wells" in August.

BP has been attempting to contain or stop the flowing oil since its Macondo well exploded April 20, killing 11 people. But the ultimate solution to permanently cap the well is to inject concrete from wells drilled in from the side.

With short-term efforts failing, officials locally and in Washington are beginning to contemplate that the oil could spew until the height of hurricane season.

"There could be oil coming up until August, when the relief wells are dug, " White House energy and climate change adviser Carol Browner said on NBC's "Meet the Press" Sunday morning. "We are prepared for the worst. ... We will continue to assume that we move into the worst-case scenario."

Plaquemines Parish President Billy Nungesser said he got weak in the knees at the Plaquemines Parish Seafood Festival when he saw the news on a Blackberry that efforts to plug the raging well with drilling mud and rubber pieces had failed.

"We're not counting on anything until this relief well is drilled, " Nungesser told CNN Saturday night.

But relief wells are something that, fortunately, engineers don't have to do very often. Drilling the relief well also can be fraught with challenges -- especially working in deep water on a well that has already had problems with gas bubbles.

"You have to hit something the size of a dinner plate miles into the earth, " said Richard Charter, a senior policy adviser at the nonprofit Defenders of Wildlife, who follows spills around the world. "Even in a shallow-water blowout, the drilling of a relief well can be complicated and problematic."

On Sunday, the White House said the government had insisted that BP drill two relief wells instead of one to ensure that it can reach the original well without problems.

Making progress

The company appears to be making progress. Spokesman Graham MacEwen said Friday that the first relief well has now reached 12,090 feet below the floor of the rig, 5,000 feet from the sea floor.

BP interrupted drilling last week to install a blowout preventer, the safety device that's supposed to seal a well in an emergency, but which failed to do so on the main well.

The second relief well, MacEwen said, is 8,650 feet below the floor of the rig.

The relief wells start about a half mile from the original site and try to meet the original at a diagonal.

Drilling a well involves using a pipe that unfolds section by section like an antenna, only upside down.

With each section, the company drills and then pulls out the pipe and puts in casings to form the sides of the well.

Drills are equipped with directional sensors that do three-dimensional surveys to help workers see where the drill bit is and what it's encountering, while metal detectors help guide it toward the metal in the original well.

Once the drills intersect with the original well, typically just above or below where the problem occurred, cement is pumped in to seal it.

Dave Rensink, president-elect of the American Association of Petroleum Geologists, said that drilling a relief well is not that different from drilling a regular well, except that the target is much smaller.

"The only problem is really finding it, " Rensink said of the original well. "You're trying to intersect the well bore, which is about a foot wide, with another well bore, which is about a foot wide. The probability of finding it the first time ... is probably pretty low."

When the company drills into the well casing but misses the right spot, it will need to set a cement plug.

As BP tries to meet the original well, it will need to have plenty of mud on hand, because when the drill actually connects, the mud from the relief well will have a tendency to get sucked into the lower pressure of the original well, and drillers could lose control of the relief well.

"That clearly is a risk. They need to be very specifically prepared when they penetrate the existing well bore, " Rensink said. "You want to make sure you're not creating a problem in your relief well that's the same problem as on your existing well."

No guarantee on timing

With the failure of the top kill, BP plans to cut off the broken riser pipe and install a cap with a "straw" in it that could siphon oil up to a drill ship.

The company may also try installing a new blowout preventer on top of the broken one and using it to try to shut off the well.

Even if the company goes that route and it succeeds in stemming the flow of oil, BP will still move forward with drilling the relief wells because it will enable the company to seal off the top and bottom of the well, making the fix more durable.

But examples from elsewhere in the world show there's no guarantee on the timing, and that drilling a relief well can be dangerous.

The world's worst well blowout and oil spill, the Ixtoc I well in Mexico's Bay of Campeche, was ultimately stopped with a relief well after a containment dome, junk shot and top kill failed, but it took nearly 10 months.

The oil platform sat in about 150 feet of water and blew out in early June 1979 at a depth of 11,625 feet.

According to a 1981 report from the Society of Petroleum Engineers detailing how Pemex, the Mexican state oil company, stopped the well, engineers decided to start drilling two relief wells at the end of June.

Progress was slow. It took one well until Nov. 20 to reach the original well, and the second took until Feb. 5, 1980.

Shutting down the main well took multiple attempts in February and March 1980 as Pemex shot drilling mud through both wells and gradually decreased the flow of oil.

The oil stopped flowing on March 17, and then it took a few more weeks to plug the wells with cement, wrapping up the operation in early April.

The blowout, according to the Society of Petroleum Engineers, lasted for nine months and 22 days.

Tyler Priest, a historian at University of Houston who has written a book about the history of offshore drilling, said Pemex thought it would go a lot faster. He cited a headline in the Aug. 6, 1979, issue of Oil & Gas Journal that reads, "Pemex: Ixtoc may flow until Oct. 3."

"They initially estimated three months. It took them almost 10, " Priest said.

'More caution' needed

Certainly, the technology today is much more advanced than when engineers fought to shut down Ixtoc, but even in modern context, relief wells don't always go smoothly.

Last August, the Thai company PTT Exploration and Production Co. was drilling the Montara well in 260 feet of water in the Timor Sea off of Australia when it well blew up and began leaking oil into the ocean.

It took 10 weeks and five tries for the drilling rig brought in to drill the relief well to hit its target about 8,600 feet below the sea floor. On the last try, there was another rig explosion, which burned for two days.

The oil was finally stopped on Nov. 3, and it took until mid-January to cap the well, according to news reports.

A final report from the Australian government on the Montara incident is due June 18.

Like the Montara well, BP's Macondo well has already shown itself to have pockets of gas big enough to interrupt drilling.

Weeks before the April 20 Deepwater Horizon rig explosion, workers on the rig experienced a gas kick so intense that they abandoned any "hot work" -- smoking, welding, cooking or any other use of fire -- for fear of an explosion.

Don Van Nieuwenhuise, a University of Houston geologist, said that BP will have to tread carefully to avoid the problems encountered at Montara.

"You have to be very careful, because you don't want to have another blowout if you hit petroleum or gas in another level, " Van Nieuwenhuise said. "Any relief or kill well needs to be drilled with more caution than the first well, because you don't want a repeat performance."

Van Nieuwenhuise speaks from experience. In 1979, he worked on killing a gas well in the Gulf of Mexico that blew up when workers ran out of drilling mud. Even though it was only in about 60 feet of water, it took about four and a half months to cap the well by drilling a relief well because of concerns about pockets of gas. "We had to stop drilling every 500 feet, " said Van Nieuwenhuise, who was working for Mobil in New Orleans at the time.

Better drilling technology today, Van Nieuwenhuise said, should make the job easier, but the key is to know where the drill bit is in relation to formations of oil and gas in the area.

BP said it's mindful of the risks and is proceeding cautiously with the relief wells.

"We've got many many safety systems in place, both procedural and technical, " MacEwen said. "We're constantly measuring the pressure in the well."