Monday, July 19, 2010

The Mother Of All Caps - 5

This series of posts discusses the cap on the Deepwater Horizon disaster well in the Gulf of Mexico, and the ramifications of that cap.

Post One, Post Two, Post Three, and Post Four preceded this current post.

That situation is that the government and BP now suspect that the well casing and/or the well bore are leaking because the pressure expectations have not been met, the pressure has remained too low within the well assembly.

The early on expectations were that if the well assembly was intact, the pressure would rise to 8,000-9,000 psi, or if there was a leak problem it would be 6,000 psi or less.

The pressure levels have been too low (~6,700 psi) for a conclusion that there is no damage to the well assembly, so it now appears that Figure 3 is the proper graphic depiction for the current situation.

Add to that the data which includes a report that seepage of hydrocarbons (gas and/or oil) through the sea floor into the gulf waters has been detected some distance from the well head:
Given the current observations from the test, including the detected seep a distance from the well and undetermined anomalies at the well head, monitoring of the seabed is of paramount importance during the test period. As a continued condition of the test, you are required to provide as a top priority access and coordination for the monitoring systems, which include seismic and sonar surface ships and subsea ROV and acoustic systems. When seeps are detected, you are directed to marshal resources, quickly investigate, and report findings to the government in no more than four hours. I direct you to provide me a written procedure for opening the choke valve as quickly as possible without damaging the well should hydrocarbon seepage near the well head be confirmed.
(Admiral Allen Letter, emphasis added). The next issues arising for investigation would seem to be: 1) how bad is the seep, 2) what is its source, that is, is it caused by a leak in the well assembly or is it natural, and 3) what is to be done about it.

Some of the dangers of the seabed in the area of Deepwater Horizon disaster are discussed in Danger Lurks In The Deep Water series.


  1. Dear Dredd,
    I read regularly your informative blog. Did you see this:
    It seems things might turn out much much much worse than expected...
    Greetings from Europe,

  2. Anonymous (Alessandro),

    The Ryskin theory, the methane bubble theory, is a "controversial scientific theory".

    A post on this blog points out that the gulf seabed is to some extent fragmented from the K-T boundary asteroid 65 million years ago which destroyed the dinosaurs and other life.

    That event would have also caused release of any large methane reservoirs near the sea floor's surface at that time, and would have broken up others deeper in the seabed by fragmentation and upheaval of the strata.

    There are many vertical fractures in the strata under the gulf waters whereby methane worms its way up toward the floor of the seabed, and sometimes seeps out.

    Remember also that methane under the seabed of the gulf is produced by microbial activity on biological mass for the most part, which is not perpetual.

    It began when the biomass and microbes were buried under the seabed hundreds of millions of years ago by another catastrophe or two.

    I have read, reported on, and linked to many scientific studies which indicate that the methane under the seabed of the gulf is composed of thousands of small bubble concentrations, millions of even smaller concentrations in fractures.

    The region contains higher than usual hydrate configurations (indicating a catastrophic event with intense pressure generated them).

    In my estimation larger bubble concentrations into a single giant bubble would more likely occur somewhere else other than the Gulf of Mexico since the last catastrophe there 65 million years ago.

    The methane hydrates are a danger to drilling there, but not to the whole world in the single-catastrophe sense.

    The methane gas, once released, is a danger to global warming scenarios because it is 30 times more powerful than carbon dioxide as a green house gas.

    The dangers in the gulf are of the type I call the straw that breaks the camel's back.

  3. Thank you for your thoughtful reply!

  4. You are welcome Alessandro.