Louisiana: Assumption Parish Bayou Corne Sinkhole 2012-2015

[Emily]

Re: Louisiana: Assumption Parish Bayou Corne Sinkhole 2012

http://theadvocate.com/home/4097747-...fer-previously

Gas found in aquifer previously
By David J. Mitchell
River Parishes bureau
October 09, 2012

The latest release of natural gas discovered in an underground aquifer near Bayou Corne may be the third time in the past 13 years that gas has been loosed in shallow formations over or near the subterranean Napoleonville salt dome, according to a review of regulatory filings....

Another important revelation in the article is that DNR officials and the group of scientists working with them have not ruled out that gas from the 2003-04 Grand Bayou incident is still in the aquifer, contrary to the impression Gulf South had until this point in time.

Also I think this is the first article that brings up the possibility that leaking wells from oil and gas exploration in the dome vicinity may have contributed to the gas burden in the aquifer. I've been wondering about this after reading about that wild well incident in 2010. There was a relief well in progress at the time it stopped spewing on its own, and the operator got permission to divert the relief well into a production well. Looking at the diagram on page 16 below, it looks like the first well overshot the oil pocket.
http://www.docstoc.com/docs/12383798...ments-that-are

When a blowout stops on its own, they assume either it spontaneously 'bridged' or the pressure was released from the pocket it hit.

To me, a 'bridged' well sounds very uncertain as to consequences. Did a collapse of the well bore underground just end up diverting the water and gas elsewhere? The well was eventually properly plugged at the surface, but the spontaneous bridge that actually stopped the blowout would be a plug wouldn't it, and possibly a poor plug?

http://www.npc.org/Prudent_Developme...ment_Paper.pdf

Working Document of the NPC North American Resource Development Study
Made Available September 15, 2011
[snip]
Unplugged or poorly plugged wells are an environmental hazard as they provide potential conduits for fluids to migrate between formations and potentially into the fresh water zones. Poorly plugged wells also might provide pathways for natural gas to seep to the surface and potentially cause fire or be a health hazards. An abandoned well?s potential for causing a
potential hazard is largely dependent on the original use of the well. Oil wells that have been pumped for years will typically be very low pressure and the risk of contamination is low while a gas well that is flowing at a rate that is non-economical can still posses enough pressure to be a risk to the environment...

[mixin]

Re: Louisiana: Assumption Parish Bayou Corne Sinkhole 2012

Here are screen caps of the helicorder readings at #3 and #9. The first one is from midnight until noon today and the second is from noon to current. Notice how the increased activity begins around 7 am. The other 4 weren't as active as these 2.

This is #3






This is #9





Here's a map of the placements of the helicorders

[Emily]

Re: Louisiana: Assumption Parish Bayou Corne Sinkhole 2012

Thanks, mixin! That's very interesting to see! The active locations look close to the sinkhole. Maybe this was involved in the latest collapse. Fortunately no workers were injured, but the last photo of the sinkhole I saw had shown great progress in cleanup. It even looked like all the debris had been removed so they could move on to dealing with the oil. Now they have more debris to pull out and operations had to stop again.

http://www.nola.com/environment/inde...ed_as_mor.html
Assumption Parish sinkhole cleanup halted as more land consumed
The Associated Press By The Associated Press
on October 09, 2012 at 3:59 PM, updated October 09, 2012 at 4:21 PM

[mixin]

Re: Louisiana: Assumption Parish Bayou Corne Sinkhole 2012

Just posted:

http://assumptionla.wordpress.com/

NEWS RELEASE

https://www.dnr.louisiana.gov

For Immediate Release
Tuesday, Oct. 9, 2012
Contact: Phyllis Darensbourg, 225.342.0058

Office of Conservation: Crude Oil Source May Link Sinkhole and Failed Texas Brine Cavern.
Analysis indicates sinkhole ?diesel slick? and liquid hydrocarbon found in cavern samples are likely raw crude oil from same source

BATON ROUGE ? Louisiana Commissioner of Conservation James Welsh said today that detailed, comparative analysis has revealed that the liquid hydrocarbon from the failed Texas Brine cavern and samples from the nearby sinkhole/slurry area strongly indicate that both are naturally occurring crude oil and not diesel ? likely from the same underground source.

Experts theorized that early analysis of the substance coating the surface of the sinkhole/slurry area showed it could be a ?diesel-range? hydrocarbon ? meaning it contains some of the same hydrocarbons as refined diesel fuel; however, that classification has now been ruled out.

Welsh said that early analysis was primarily aimed at establishing potential toxic effects, and used the term ?diesel-range? as a rough classification, with further analysis needed to determine the nature of the substance more precisely.

?Distinguishing between ?diesel fuel? and ?diesel-range crude oil? is critical to the effort to ensure public safety by determining the cause of the cavern failure and the sinkhole, and their possible link to each other and to the natural gas that has been found in the aquifer in the Bayou Corne area,? Welsh said. ?While our ongoing review of operational records on the Napoleonville Salt Dome has not shown one single underground source known to contain enough diesel fuel to cover the sinkhole/slurry area, an underground oil-and-gas formation could easily account for the amounts found on the sinkhole/slurry area surface and in the cavern.?

Welsh said that better understanding of the source of the crude oil could also help better identify the source of the natural gas in the aquifer because oil and natural gas are often found together in productive formations.

Additionally, he noted that ongoing ?fingerprint? analysis of natural gas samples from Bayou Corne-area bubbling sites has now ruled out the nearby Crosstex butane storage caverns and Acadian natural gas storage caverns as potential sources of the natural gas bubbling.

Welsh also said that as analysis of the failed cavern and sinkhole is ongoing, work has progressed on construction of the vent wells ? with initial flaring of natural gas expected to begin by Friday.

?We discovered natural gas in both wells sites near the sinkhole and are now working as quickly as possible to remove it through these vent wells,? Welsh said. ?However, the initial analysis of the third well, sited on the west side of Bayou Corne, reveals that it does not have an accumulation of natural gas, though analysis will continue at that well as the work continues throughout the area to resolve the situation for the community.?

Patrick Courreges
Department of Natural Resources
225-454-8223
assumptionla | October 10, 2012 at 6:35 am | Categories: Uncategorized | URL: http://wp.me/p2Ed3J-eN

[mixin]

Re: Louisiana: Assumption Parish Bayou Corne Sinkhole 2012

Some highpoints from the meeting yesterday:

http://assumptionla.wordpress.com/

* Hydrocarbon from the failed Texas Brine cavern and samples taken from the sinkhole strongly indicate that both are naturally occuring crude oil (not diesel) and likely coming from same underground source
* Analysis of the failed cavern and the sinkhole are ongoing
* Flaring of the vent wells on Highway 70 are expected to begin flaring on Friday
* Results of Isotopic samples taken from bubbling discovered on private property on Bayou Drive in Pierre Part have been determined to be swamp gas and not natural gas. Results show that the bubbling is not associated with this incident

********************
Texas Brine has provided profiles of the sinkhole. The deepest point is 449'.



You can find that at the Assumption Parish site


or at this direct link

*************

Also released at the DNR site are 2 very informative docs:

Direct links:
-Current Status of Cavern Operations
-Precision Level Surveys & Subsidence Analysis

[Emily]

Re: Louisiana: Assumption Parish Bayou Corne Sinkhole 2012

Thanks for posting the sinkhole profile, mixin! It's amazing how jagged it is. The parish site says a big section of Acadian Gas's pipeline just popped to the surface there today. It had been emptied so the concern would be for cleanup workers as far as a collision. They are using an airboat to push debris to the long-reaching crane for removal. Also it sounds like they are back at work in sinkhole today already.

The parish also reported that LA 70 was closed again after a startling flare from the Crosstex site. That was determined later to be within normal operating parameters, but just very large.

The Advocate has an extensive article covering some of the points in your post. They discuss the mystery of the material in the bottom of the cavern:

http://theadvocate.com/news/4121479-...s-gas-sinkhole

Expert links gas, sinkhole
Geologist: Connection seen in info
By David J. Mitchell
River Parishes bureau
October 11, 2012
[snip]
Material believed to be a shale sediment was found inside the plugged and abandoned Texas Brine salt cavern, apparently filling about 1,500 feet of the 2,250-foot-long cavity and pointing to some kind of cavern failure along its lower side.

I haven't been able to find another case exactly like this where the side of a cavern collapsed. I saw a report about a 'salt fall' in an SPR cavern, but they are saying this is shale, not salt. That's confusing since you'd think the walls of a salt cavern would be made of salt, but maybe the shale is indicative of the 'breach' that was suspected in 2011, and concern that the salt dome boundary was closer to the well than originally thought.

[mixin]

Re: Louisiana: Assumption Parish Bayou Corne Sinkhole 2012

I started listening to the meeting videos but got sidetracked at #3. Texas Brine sent a rep and he talked for about 10 minutes. He said the sediment is a dark gray shale-type material, which almost gives the appearance of wet cement.

New findings were posted last night in a 4 page PDF (which won't allow copying) so I made this brief summary of the important points.

* it's believed that there is a side breach and a side wall collapse in the cavern
* it now contains 3.3 million cubic yards of material and 700,000 cubic yards of brine
* based on the location of the sinkhole, the movement of the material from the outside of the cavern into the cavern likely followed the edge of the salt from the cavern to the surface, resulting in the sinkhole
* the volume of the sinkhole is 550,000 cubic yards.
* it has to be assumed that the collapse zone is currently unstable
* the gas has all of the characteristics of natural gas
* based on chromatograms, the hydrocarbon liquid from the sinkhole surface has the same characteristics as the cavern, except for the absence of light-end hydrocarbons which is typical when exposed to surface environment.
* eliminated as probable sources: Chevron, Acadian, Crosstex and residual gas from the 2003 Gulf South blowout.
* remaining probable source: Big Hum, Marg A, Cris R, and Marg Vag production zones
* current data indicates the failure of the Texas Brine cavern provided an upward path of migration for crude oil & natural gas previously confined to a naturally occurring formation, allowing accumulation of NG in the alluvial aquifer and causing the bubbling sites.
* ~10 ft of gas accumulation has been found near the TB core-hole and ~ 5 ft accumulation has been detected NW of the Oxy 3 facility and the sinkhole. Additional gas or crude oil migration is possible.
* TB given 8 measures to undertake regarding upgrades, installations, etc. and failure to comply may result in civil penalties.

Direct link

http://dnr.louisiana.gov/assets/OC/BC_All_Updates/12.OC.OCTORDER.pdf

[Emily]

Re: Louisiana: Assumption Parish Bayou Corne Sinkhole 2012

The Daisetta, (photo on the right), sinkhole is so far the only one I could find that had crude oil and debris on top of it like the one at Bayou Corne. Daisetta is in a shallow salt dome in east Texas so somewhat similar geology to the Napoleonville dome. (That 'Wink Sink' area is in west Texas.)

http://www.beg.utexas.edu/staffinfo/..._sinkholes.pdf

Paine, J. G., Buckley, Sean, Collins, E. W., Wilson, C. R., Kress, Wade, 2009, Assessing sinkhole potential at Wink and Daisetta using gravity and radar interferometry: in Proceedings, 22nd Symposium on the Application of Geophysics to Engineering and Environmental Problems, Fort Worth, Texas, March 29?April 2, p. 480?488.

What might be different is the source of the crude. I have not seen that explained for the Daisetta sinkhole, and you can see storage tanks falling into the hole as it opened.
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Also I did not see anything about gas being released in Daisetta, though it sounds like injected waste was released.
http://www.chron.com/news/houston-te...#photo-1234291

The report also stated the force of that collapse created an underground wave of fluids that pushed up through the mayor's unplugged well and two others.

That spray left everything in its wake ?graveyard dead,? declared the mayor. Wells said the fluid flowed like a river over six acres of his property. New vegetation has started to replace the crunchy brown grass, but none of his trees survived. ?I'm having to cut down 100 of them,? he said. ?This was potent stuff.?

[Emily]

Re: Louisiana: Assumption Parish Bayou Corne Sinkhole 2012

http://theadvocate.com/home/4142733-...on-area-safety

By Bret H. McCormick
River Parishes bureau
October 15, 2012

BAYOU CORNE
[snip]
The problem residents have when trying to plan for the future, Carolyn Welch said, is they simply don?t know when they?ll be allowed to return home.

?The uncertainty and not knowing when it?s going to be over? has been the hardest part, she said. ?It could be two months. It could be two years. We just don?t know.?..

[mixin]

Re: Louisiana: Assumption Parish Bayou Corne Sinkhole 2012

Using the ?benefit of hindsight,? Waguespack said Texas Brine officials should have continued to monitor their well after a failed integrity test in 2010 instead of simply plugging it, abandoning it and moving on.

?It seems these guys should have put a little bit more controls in place to monitor the situation,? Waguespack said.

In the letter from Texas Brine to Joseph Ball, Jr. at the DNR:
"Texas Brine provides this information for the purpose...and also to seek DNR guidance in developing a plan for continuous monitoring." So an answer as to why it wasn't done should be forthcoming.

"vertical seismic data gathered during the workover" is also referred to in that letter; I wonder if that data is this view the DNR has on its website.

There is some real confusion as to how the oil has gotten from the outside of the dome, into the cavern and back out again to migrate to the sinkhole. So I did some speculating with this view. I assume this view is similar to viewing a globe of the earth.. that it would rotate in a circle. So I added that short, white rectangle (inside the green salt dome) where I think the cavern is, if the numbers at the right are meters. If I'm right about the rotation of the view, then the sinkhole is to the right of of the cavern.

That also meshes with their statement that the Big H, etc, layers lay against the dome wall near the cavern.

So, for the sediment to get into the cavern, it and the dome wall are likely damaged. But that still leaves the question of how the sediment got out of the cavern and into the sinkhole. This in an official statement

current data indicates the failure of the Texas Brine cavern provided an upward path of migration for crude oil & natural gas previously confined to a naturally occurring formation, allowing accumulation of NG in the alluvial aquifer and causing the bubbling sites.

but they say there is no breach above the new cavern bottom.

I'll add the disclaimer that my speculations could be totally wrong.

[Pathfinder]

Re: Louisiana: Assumption Parish Bayou Corne Sinkhole 2012

STATE OF LOUISIANA
DEPARTMENT OF NATURAL RESOURCES
OFFICE OF CONSERVATION
THIRD AMENDMENT TO DECLARATION OF EMERGENCY AND DIRECTIVE

Commissioner's Order (updated 10/16/12)

[Pathfinder]

Re: Louisiana: Assumption Parish Bayou Corne Sinkhole 2012

As of 19 October 2012

Assumption Parish

Operational Situation Summary

? Department of Environmental Quality

? Hydrocarbons and dissolved natural gas confirmed in water at slurry site;
chlorides slightly elevated at surface samples; data for deep samples also shows
elevated Salinity as well as indicators of Natural Gas condensate as expected.

? Air monitoring for VOC?s continues with no dangerous levels detected off site
(1000? away).

? On going Water sampling/water quality monitoring in Bayou Corne and Grand
Bayou indicates no water pollution associated with the incident to date.
...
? As of 18 October, Texas Brine has removed 75 roll off boxes hydrocarbon
contaminated debris.

? As of 18 October, Texas Brine has removed approximately 450-500 Barrels of
hydrocarbons from the surface of the sinkhole.
...

Scientific Situation Summary

? USGS:

? Source of seismic activity estimated between 200 and 600 meters deep

? Continuing to monitor seismic activity at the six seismograph locations

? USGS reported limited seismic activity---average of one tremor a day---direction
NW of sinkhole and other side of the pipeline right-of-way---Dr. Horton stated the
science behind the recent events does not suggest a heightened level of risk at
this time.

? USGS confirms no seismic activity in the area of the butane caverns

? Representative of the science group discussed dome mechanics and surveys for
investigatory well with representative of USGS and Sandia National Lab

? In response to Texas Brine?s assertion that region seismic activity caused their
cavern to be compromised, USGS stated (on 25 Sept. 2012) that it is their belief
that the seismicity is a consequence of the collapse of the cavern, and not the
cause of the collapse of the cavern and the formation of the sinkhole
...

? Scientific Workgroup Scientific Situation Summary
theories of cause:

? Salt Dome moving ? natural migration of gas
? Failed cement casing in OXY #3 well
? Cavity Failure
? Salt / Caprock falling from top of the cavern
? Natural
? Man-made (including penetration into sediments by cavern)
? Gas storage cavern connections, communications by fractures
? Low permeability seepage of gas into OXY #3 (source unknown)
? Regional Tectonic activity (movement on growth faults)
? A combination of above events
...

Full text:

http://www.edsuite.com/proposals/proposals_280/assumption_update_october_19-2012_fi_503.pdf

[Emily]

Re: Louisiana: Assumption Parish Bayou Corne Sinkhole 2012

http://theadvocate.com/home/4209995-...th-doesnt-work

Officials: Sinkhole math doesn?t work
End date of evacuation remains unclear

By David J. Mitchell

River Parishes bureau

October 22, 2012

The math isn?t adding up in Assumption Parish, and some parish officials are worried about what might be happening underground near a Bayou Corne area sinkhole...

3.3 million cubic yards of sediment goes into cavern
550,000 cubic yards is the estimated sinkhole volume
3,300,000 - 550,000 = 2,750,000 cubic yards of voided space underground that is unaccounted for.

[mixin]

Re: Louisiana: Assumption Parish Bayou Corne Sinkhole 2012

Regarding the unaccounted for voided space, I assume the shale in the Big H, Marg A and Cris R is made up of slabs large enough to pile on top of each other until the empty space formed a cavern. If the salt cavern collapsed in just that one area, I wonder why they think it's possible for a sinkhole to open up elsewhere?

The more I look at the different diagrams, the less I understand what's happening. The shape of the sinkhole is puzzling... how it narrows down to almost a point; the stuff that drained out of it must have been pretty fine? It's 400+ feet deep; I wonder what the layer of sediment is like at that point. I can't find much info on the layers surrounding the salt dome.

The briefing is tonight; hopefully we'll get some answers.

There was another flyover posted at YouTube today; the greenway is slowly going under water and the sinkhole still looks like it still has a lot of oil in it.

[Emily]

Re: Louisiana: Assumption Parish Bayou Corne Sinkhole 2012

The shape of the sinkhole is puzzling... how it narrows down to almost a point..

I'm listening to the videos of last night's meeting. (I just quickly listened so let me know if I have any facts wrong here.) The scientist from Shaw consulting is speaking the video below and I think he referred to what happened as a "frack-out", (that is hydraulic fracturing caused by pressure problems around the cavern), with the sinkhole being at the top of the fracture zone that goes from the cavern about 5,000 ft underground all the way up crossing 3 oil and gas production zones on the way. (And as you thought, he said the void areas might be interspersed along that almost mile long fracture among the rubble with some being full of brine.)

He said this is an unprecedented event. (I read that the oil in the Daisetta sinkhole was from undergound storage, not a natural release, so that event was quite less complex.) They are consulting with other experts all over the world, but there is no blueprint to guide them with this situation and the clay is causing them problems, so they are having to innovate quite a lot.

So far no gas has been vented but they will continue to work on that. The Shaw scientist said that gas started to bubble up through the sinkhole over the past couple of days so there is now a direct pathway from it to the gas producing layers deep underground. He's hoping this is a good sign in that this will vent gas and slow lateral movement of gas through the aquifer. They have not been able to get a reading on pressure building in the aquifer yet due to the clay clogging equipment up.

Texas Brine's representative said in an earlier video that they have removed about 600 barrels of oil from the sinkhole. They have to wait for wind to blow it to a stable place on the shore in order to capture it safely. They got 2800 barrels of oil out of the cavern and think that both sources are not refilling with more oil, which is good. He talked at length about real-time monitoring devices being installed to measure cavern pressures, sinkhole liquid levels, and ground deformation (I think). He also mentioned that another company in the dome is cooperating with their monitoring, which is good. I was hoping some of the other companies would get involved.

A representative from the parish talked about wanting to do seismic reflection studies, (I think), but they can't afford it so hope that DNR and Texas Brine will work together and get that done. The Shaw consultant said that the cavern was closed off per the standard procedure, so apparently no real-time pressure monitoring of closed wells is required.

Maybe that will change in the future. I think I read that there has been debate over that point in the industry and that some operators, maybe in Europe, have experimented with leaving the caverns vented for awhile after they shut them down.

Maybe there will be requirements to do detailed seismic reflection studies prior to mining or even expanding caverns, especially if near the flanks of a salt dome. I saw an abstract for an environmental geology paper that said the technology is much better now than it was 20 years ago, so updating site surveys could save companies from costly troubles, even though it sounds like the studies are expensive themselves.

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