Pages

Sunday, June 27, 2010

Danger Lurks In The Deep Water

The state bird of the Gulf of Mexico (GOM) is now the oil covered pelican dying in toxic oil.

It is also symbolic of an oil based civilization that is in the process of destroying itself.

I gathered some research papers that document studies of the GOM that were produced from data gathered from 1999 through 2009.

That research focused on the dangers inherent in the deepwater drilling in the GOM as a result of methane hydrates commonly found there, including substantial analysis of various sorts (the index is 163 pages):
NOTE: This document contains a listing of all published reports and professional presentations relating to work supported by DOE’s Methane Hydrates R&D program. While many of these reports are “shared” publications, with support being obtained from several funding sources, we have endeavored to include only those reports in which the DOE's contribution was meaningful and substantial.
(Index To Research Papers,  page 163 [Wayback Machine copy, they "lost" it]). We could spend years reviewing all the material, so I chose to focus on only a few issues, issues related directly to the Deepwater Horizon catastrophe.

One of the issues is the "loop current", which we have been told is way south of the well-head, but that is not what documents in this set indicate:
At the [Atwater Valley] location, the presence of excessively high loop currents that were an order of magnitude higher than the current velocities used in pre-drill models greatly enhanced the transfer of heat from the drill pipe to the ocean. The current velocities used in pre-drill models were obtained from a sparsely populated NOAA database. These velocities may have provided a reasonable indication of average conditions. However strong loop currents were not anticipated. Once loop currents are accounted for, model predictions were shown to agree quite well with LWD temperatures.

Post-drill simulations indicated that the LWD boreholes in Atwater Valley and Keathley Canyon were sufficiently cool to prevent hydrate from dissociating. This was due in part to management of circulation rates in the borehole. However it was also shown that in the absence of loop currents at Atwater Valley, the risk of dissociation would have been significant.
(Semi Annual 2006-2007 Report, page 26, emphasis added). This begs the question, "where is Atwater Valley?"

An MMS Accident Report dealt with some troubles on the Deepwater Pathfinder rig while it was in "Atwater Valley".

Maps in the report show Atwater Valley to be at or very close to where the Deepwater Horizon site is located (MMS Accident Report, page 29).

Does this mean that the "excessively high loop currents" have been taking the underwater, out-of-sight, massive islands of gushing petroleum products elsewhere, contrary to government statements?

Or have the loop currents moved south away from the Deepwater Horizon site as the government says, and if so when, why and how?

The reason that is important is that these reports show that water temperature can have an effect on drilling in hydrate rich areas, and in fact can be very dangerous:
Throughout early 2009, the JIP has pursued permitting and hazards analysis for five sites (AC21/65; EB 955, GC 992; WR 313; GC 781/825; Figure 2). The site in AC 818 had earlier been deemed too risky for Leg II drilling due to expected reservoir overpressure and was dropped from the Leg II program. However, because of preexisting data the site remains a candidate for GoM JIP Leg III coring activities if the drilling hazard issues can be addressed. As of this writing, ongoing industry activity at two of the locations (EB 992 and GC 781) renders the JIP’s ability to drill at those locations uncertain.
(Hydrate Dissocation, emphasis added). A news source points out why this is so much a factor to consider:
Methane hydrates are volatile compounds — natural gas compressed into molecular cages of ice. They are stable in the extreme cold and crushing weight of deepwater, but are extremely dangerous when they build up inside the drill column of a well. If destabilized by heat or a decrease in pressure, methane hydrates can quickly expand to 164 times their volume.
(Guardian, emphasis added). Dredd Blog has pointed out the destabilized nature of the seabed in Gulf of Mexico deep water areas, which happened during the K-T extinction event 65 million years ago.

In another Dredd Blog post, Is A New Age of Pressure Upon Us, we noted that global warming applies to the oceans, the resultant rising oceans effect pressures on the seabed, and therefore wondered how those should be factored into the equation.

These reports linked to in this current thread show we were on track, because that is exactly what must be considered and paid attention to when methane hydrates are a factor.

In upcoming posts we will discuss the formation of dangerous seabed domes (hills) and other deformities, such as cave-ins, caused by pressure changes inside hydrate reservoirs.

The second of this series is now posted here.

2 comments:

  1. Obviously, the decision to drill there was a "damn the torpedoes" type decision, it did not matter how dangerous it was, that it was likely to be a super high pressure deposit, that the currents were too strong, that the hydrates might explode and rupture the casing...there was oil there, and it was going to be drilled for if there was hell to pay.
    There is, and hell now demands payment!

    ReplyDelete
  2. Helixtwice,

    Hell does not practice fair standards.

    If it did it would only require the heads of the BP and government people responsible.

    Instead, hell takes the lives and livelihood of innocents, whether human, animal, the environment, or anything else in a hellish blind rage.

    Hell can kiss my a**!

    ReplyDelete