Friday, June 4, 2010

Pipe up the Leaking Oil: An Initial Success!

BP announced earlier today that "oil and gas is being received onboard the Discoverer Enterprise following the successful placement of a containment cap on top of the Deepwater Horizon's failed blow-out preventer (BOP). This follows the cutting and removal of the riser pipe from the top of the BOP's lower marine riser package (LMRP)."

Congratulations to BP, U.S. Government, and everybody involved!

I hope performance of the system would be enhanced soon to minimize or eliminate the residual oil leak around the imperfectly fitted/sealed cap.

Sunday, May 30, 2010

Pipe up the Leaking Oil - The New LMRP-Cap Attempt to Succeed

It has been more than one month since BP (British Petroleum) and the U.S. Government started to attempt stopping the catastrophic oil leak at Gulf of Mexico. I have not paid much attention until yesterday when I heard that an estimated 20 million gallons of oil have already leaked out, and the latest attempt to "top kill" the leak failed.

In general, it is easier to channel out the flow than to plug the flow. I hope the new "flow channeling" attempt, using the Lower Marine Riser Package (LMRP) Cap Containment System, would work.

The idea (see the graph) is to connect the LMRP Cap to oil outlet of the Blowout Preventor (BOP), with the help of Remotely Operated Vehicles (ROVs). The oil would then be piped up to the waiting surface ship, approximately 5,000 ft above.

The cap (with the pipe on top) must be lined up with the BOP outlet, and be connected and sealed to it, all to be done inside the oil gusher under an extremely high ambient sea water pressure (above 2,000 pounds per squared inch) and dark, turbid environment. I visually estimate the gushing oil would have a flowing velocity of only about a foot per second. The relatively weak oil gushing velocity, alone, should not create a problem for the pipe lining up and connecting. The high ambient pressure would not be a huge inconvenience either as long as pressures inside and outside the cap (and the pipe) are maintained essentially the same.

The question is whether this new attempt would succeed. I think it would. Many lessons have been learned from the previous attempts, especially on formation of the gas hydrates (the ice crystals).

There is also a concern about whether the new attempt would make the matter worse if it were to fail. I do not think it would make it worse, at least not significantly. There are multiple openings (at least two large ones) along the collapsed riser pipe at this time. Cross section area of the sole opening to be cut at top of the BOP should not be much larger, if at all, than sum of the areas of multiple openings. Moreover, change in the head losses would have a minor effect, considering the oil pressure head available.

The oil leak and subsequent several failed attempts (thus far) to stop the leak, yet again, highlight the importance of disaster prevention, preparation, response, and emergency engineering measures.

Image credit: BP

Saturday, March 27, 2010

Severe Drought Hit Southwest China

Impacts: The dry spell has ravaged southwest China for months, affecting 61.3 million residents and 5 million hectares (12 million acres) of crops in Guizhou, Yunnan, Sichuan, Chongqing, and Guangxi. The drought has left 18 million residents and 11.7 million heads of livestock in the region with drinking water shortages and caused direct economic losses of 23.7 billion yuan (3.5 billion U.S. dollars).

Emergency responses: 30-thousand soldiers and 200-thousand reservists are busy with the relief work. They delivered 44-thousand tons (12 million U.S. gallons) of fresh water and dug nearly 1-thousand wells in the drought-plagued region; An effort is also being made to induce artificial rain; etc.

Causes: Less than a half of normal rainfall and continuous high temperature, resulting from the El Nino weather pattern in the tropical Pacific Ocean since last Summer; Karst topography in some areas where the surface water is leaked to the almost intractable subterranean drainage system; Contamination of some source waters by human activities; Lack of drought-defense engineering measures; People farming and living sparsely in remote mountainous villages making them difficult to reach during the emergency response; etc. Identifying the causes would hopefully lead to proper long-term solutions.

Photo: Rice paddy fields in the mountainous area, from

Saturday, March 20, 2010

New Jersey Flooded, Again, by March 2010 Nor'easter

Five to eight inches of rain hit New Jersey causing serious flooding, again. Strong winds also uprooted trees and downed power lines. The severe flooding has again triggered debates on conquer (engineering projects) vs. retreat (home buyouts). The debates tend to go on forever, but we probably can not afford to wait much longer.

Photo: Flooding along Passaic River, from