Last night the Denton City Council passed a 120 day moratorium on new drilling permits. A huge thanks is due all the UNT students who attended the many dysfunctional task force meetings, stayed involved and are currently registering and motivating new voters.
I think the council had already decided before the public input but I still gave them information about water contamination in Denton that showed Ed Ireland’s comments during the task force meeting and Gilbert Horton’s comments during the council meeting were false. I also delivered the council comments about yesterday’s task force meeting from Kathy Martin who is a petroleum engineer. Here are her comments:
Written Comments Regarding Technical Task Force Discussions on 2-6-12
Kathy Martin, petroleum engineer
Ed Ireland stated that several layers of protection would need to fail simultaneously to have gas losses to the groundwater.
My comment: That is only true with leaks from the production tubing. Gas seepage from the producing formation traveling up the annular space of the wellbore has no layer of protection or at the very least a layer of cement that has been subjected to the rigors of multiple frack jobs.
Darren Groth Groth stated the city inspects each producing well twice a year and they look at casing pressure.
My comment: Which annular space is the casing pressure measuring? We understand that there would be conductor and surface casing at the surface with corresponding cement layers. But what happens below the surface casing where there is no cement between the open borehole and the intermediate casing (if that is even present).
John Siegmund stated a hole in the surface casing (from corrosion or otherwise) doesn’t hurt the water again claiming there are layers of protection between the production tubing and groundwater.
My comment: A hole in the surface casing made by corrosion implies that the casing was exposed to something corrosive for a long enough time to corrode the metal casing. John Siegmund completely ignored this aspect and did not acknowledge that groundwater would be exposed to that corrosive liquid/gas as well.
John Siegmund stated that it would be unnecessary to repair a hole in the surface casing unless production gets through all of the layers.
My comment: Industry members of the task force repeatedly ignored the issue of gas in the annular space not from a leak from production tubing but from leaks at the producing formation itself that travels directly to the surface along the exposed wellbore and through faulty cement.
Dr. Thomas La Point discussed the Pavillion, Wyoming gas migration study and stated that the shallow gas formation was the reason there was gas in the aquifer and that there was only a separation of 500 feet between the two. He went on to say that because the Barnett shale was nearly 5000 feet below the aquifer that it would be impossible to contaminate the groundwater – implying that the contamination in Wyoming was due to a frature that extended 500 feet into the groundwater and that it would be impossible to have a fracture extend 5000 feet here in Denton.
My comment: The distance between the fracked formation and the aquifer has nothing to do with the potential to contaminate the aquifer if the gas travels from the producing formation up the wellbore to the surface and finds pathways to overlying formations.
My comment: What is industry doing to prevent gas migration into the wellbore directly above the fractured formation and how do they guarantee that methodology continues to work during the life of the well?
Don Butler stated the surface casing is set to prevent pollution of the aquifer by drilling mud.
My comment: Surface casing is set to provide hole stability and to prevent groundwater from flowing into the well during drilling. It is first a convenience and necessity for drilling. It is coincidental that surface casing could be used to protect aquifer formations. The amount of cement required to set casing is not determined by its ability to prevent gas migration from the annular space into the aquifer but to keep groundwater from flowing into the wellbore.
Don Butler stated the the TCEQ no longer determines the lowest protectable groundwater and that the RRC now determines that depth of surface casing.
My comment: The regulations clearly state that TCEQ makes the determination.
John Siegmund said that cement wouldn’t even be necessary for surface casing except to protect groundwater.
My comment: This is wrong. The cement is necessary to position the surface casing straight in the hole so that sub sequent drilling can be accomplished with unnecessary deflection.
Dr. Thomas La Point discussed isotopic monitoring and implied that it would useless because you would not be able to identify a particular well as the source of the natural gas in a groundwater well.
M y comment: The purpose of isotopic monitoring would be to distinguish the source of methane from Barnett shale versus other sources, such as septic tanks. Determining which particular well polluted the aquifer could be accomplished with other types of deductive reasoning. The key benefit of isotopic monitoring is to establish that the aquifer is or is not contaminated with geologically old sources of methane. See www.papgrocks.org/ferworn_p.pdf for graph of methane carbon isotope versus gas wetness and the obvious delineation between young C13 and older sources.
Ed Ireland stated that water recyclers needed pits to operate and that since pits were outlawed, recyclers could not operate.
My comment: Modern water recyclers can come to the well site with tanks on skids and perform some waste separation on site. Others have permanent facilities were wastewaters are treated in above ground tanks (coagulation/precipitation and evaporation/distillation).
John Siegmund asked if the wastewater could be disposed of in the lake.
My comment: That question speaks loudly to the lack of understanding of environmental restrictions already in place that would prohibit discharge of treated or untreated oil and gas wastewaters to waters of the state and nation. It also is symptomatic of the fundamental disconnect between industry task force members and the reality of the seriousness of oilfield waste and wastewater disposal.
Denton Record Chronicle story.
Now Denton must do something about the dysfunctional task force!
About Sharon Wilson
Sharon Wilson is considered a leading citizen expert on the impacts of shale oil and gas extraction. She is the go-to person whether it’s top EPA officials from D.C., national and international news networks, or residents facing the shock of eminent domain and the devastating environmental effects of natural gas development in their backyards.
- Web |
- More Posts(5116)
2 good articles on this showed up:
Wow!! Congratulations, Denton!!