Showing posts with label Blowout preventer. Show all posts
Showing posts with label Blowout preventer. Show all posts

Tuesday, June 29, 2010

Two drill pipes discovered inside wreckage of the well

A blowout preventer.Image via Wikipedia

Second pipe may have crippled BP well's defense mechanism

The gushing BP oil well is a mystery still unfolding, and late last month, a team of scientists from the Energy Department discovered a new twist: Their sophisticated imaging equipment detected not one but two drill pipes, side by side, inside the wreckage of the well's blowout preventer on the bottom of the Gulf of Mexico.

BP officials said it was impossible. The Deepwater Horizon rig, which drilled the well, used a single pipe, connected in segments, to bore 13,000 feet below the ocean floor. But when workers cut into the wreckage to install a containment cap this month, sure enough, they found two pipes.

The discovery suggested that the force of the erupting petroleum from BP's well on April 20 was so violent that it sent pipe segments hurtling into the blowout preventer, like derailing freight cars.

It also offered a tantalizing theory for the failure of the well's last line of defense, the powerful pinchers called shear rams inside the blowout preventer that should have cut the pipe and stopped the rising oil and gas from reaching the Deepwater Horizon 5,000 feet above. Drilling experts say those rams, believed to be partially deployed, could have been thwarted by the presence of a second pipe.

The doubled-up drill pipe joins a list of clues that is helping scientists understand the complexities of the Deepwater Horizon accident, and from that, craft changes in how deep-water drilling is conducted. More...

Monday, June 14, 2010

"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,
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...