By Vanesa Brashier, editor@bluebonnetnews.com
Richard Howe was hoping to never return to Daisetta to investigate a new sinkhole. Fifteen years ago, Howe, principal geologist for Terra Cognita, LLC, provided an expert opinion and studied the original sinkhole that formed dramatically over a 3-4-hour time span on May 7, 2008, when a section of the Daisetta salt dome collapsed unexpectedly.
On Tuesday, Howe and retired petroleum geologist Gary Kowalczyk met with city, county and state officials at Daisetta City Hall. During the meeting, Howe explained that he believes the Daisetta sinkhole, as well as at least four other previously existing sinkholes in the Daisetta area, are the direct result of oilfield operations that began in the 1920s.
“If you look at an oilfield production map, on the scale of the map is a black solid ring on the flanks of the salt dome under Daisetta. That’s where the oil was. There was hardly any production at all on top of the salt dome. It was in the beds where the salt came up and pinched and trapped oil. Back in the day [of Daisetta’s oil boom], you could walk from rig floor to rig floor because they were so tightly spaced,” Howe said. “There are all kinds of wells. A lot of them were never properly plugged or capped. I would assume there is some contribution from these uncapped wells acting as conduits of fresh water to the subsurface.”
This means that the oil drilling from the 1920s is likely to blame for the original sinkhole as well as the new one that began erupting on Sunday, April 2, right next to the old one.
“We were hoping that the sinkhole was stabilized. If you look at what we see right now, it appears a new sinkhole is actually erupting. It looks circular. Our premise is that it could keep going along the flanks of the dome,” he said.
Whether the new eruption is simply an expansion of the 2008 sinkhole or is being caused by another collapsing chamber of the salt dome is still unclear. Researching the origins of the new sinkhole will require geological testing, and possibly seismic testing, which the City of Daisetta simply cannot afford.
As frustrating as it might be for Daisetta residents and officials who are monitoring the sinkhole’s progression, Howe recommends a wait-and-see approach and is encouraging the City of Daisetta to install benchmarks that can be used to monitor any further disruptions. One low-cost benchmark method involves driving T-posts into the ground in a straight line and using a laser level. These would be checked frequently to see if any of the T-posts are disrupted and fall out of line, which could indicate more shifting in the ground.
Regardless of the cause and how or if the salt dome will expand, Howe said it is clear that something is dissolving the caprock, false cap or the salt dome. A caprock can be compared to a lid that traps oil, gas or water, and keeps it from reaching the surface. A caprock can be compromised when the cavities under it begin to dissolve.
Howe said sinkholes are often a natural phenomenon.
“They don’t have to have man’s influence to do anything. Man’s influence can aggravate them, however,” he said.
Uncapped wells could be one such aggravation. As the 2008 sinkhole was forming, an abandoned well on the property of the late Daisetta Mayor Lynn Wells suddenly gushed like a geyser, dumping an unknown substance onto his property.
“On the very south of town, it came out of an uncapped oil well and sprayed there,” said Howe, remembering.
MORE AGENCIES ARRIVE IN DAISETTA
On Wednesday afternoon, representatives with the Environmental Protection Agency arrived and are assisting the Texas Commission on Environmental Quality. The EPA is expected to dispose of any hazardous waste that may be found. TCEQ will be handling the non-hazardous waste.
“TCEQ is doing tests to determine what is hazardous waste and non-hazardous waste. Republic Services is the contractor for testing through TCEQ,” said Nat Holcomb, assistant to Liberty County Fire Marshal Bill Hergemueller, who also heads the Liberty County Office of Emergency Management.
Also arriving on Wednesday were Texas Department of Transportation representatives who will be inspecting the safety of FM 770 as it is only 80 feet from the edge of the original sinkhole.
“There is a dip in the road and we aren’t sure how long it’s been there. We want to know if it’s something to be concerned about. It’s just another tick in the box,” said Hergemueller, stressing that testing of the road is precautionary. “We are simply doing our due diligence to protect the public.”
The Texas Department of Emergency Management has had representatives on the scene and working with local officials since Monday.
With the storm that blew through Southeast Texas on Wednesday, high winds made it impossible for the LCOEM to fly its drone and capture aerial photos to compare with those taken earlier in the week.
I was told by txdot crew in liberty the dip has been there since 2008