Hydrofracking - are we nuts? (OT)


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Social climber
An Oil Field
Sep 20, 2014 - 12:17pm PT
Regarding the earthquakes rattling the snot out of Oklahoma, there is a lot of baloney out there on the web and in popular media.

When you frack a well, you have a bunch or high powered pump trucks that can inject the water/sand mixture at high pressure. After you are finished injecting, you open the wellhead and flow back all of that frack water. You get most of it right back, and you only affect downhole pressures for a short period.

That is why fracks don't cause very many earthquakes. There was a recent paper where there was an earthquake swarm associated with fracking a horizontal in southern Oklahoma. The were all less than mag 2.0.

Out of the other thousands of horizontal fracked wells, I'm not aware of any other earthquakes. I keep track of what is going on at the Survey, too.

On the other hand, injection wells have long been associated with earthquakes. In the past few years a couple of areas in Oklahoma have gone insane, with daily earthquakes in the 3.5 or less range. Still, 3.5 is a big deal, and Oklahoma is now having a lot more earthquakes than California. Injection wells are active for decades, and over time they can raise the pore pressure in the injection zone. Increasing this pore pressure is the culprit. Fracks only affect a tiny area for a few days. Injection wells affect bottom hole pressure til the end of time.

Almost all oil wells also produce saltwater. The saltwater is separated at the tank battery, and the oil goes into the oil tanks, while the saltwater goes into its tank. When the saltwater tank fills up, which might take years on some wells and days on others, you call up a company which manages a commercial saltwater disposal well. They truck away your saltwater and dispose of it in a highly regulated commercial injection well.

Those wells are closely watched and regulated, and have to have a mechanical integrity test (MIT) annually. They check casing integrity by setting a plug just above the injection perforations and pressuring up the casing. If you have a leak, you will see a rise in the pressure on the backside of the main casing string, at the annulus gauge on the wellhead.

Oklahoma injection wells now require daily records of volumes injected, and pressure readings between all of the casing strings.

The first area to begin having earthquakes was in an area that had no fracking going on at all. It was in a region where the Hunton Dolomite was being produced. Those wells made thousands of barrels per day of saltwater along with oil. The saltwater would have cost way too much to dispose of commercially, so operators would drill a deep disposal well on about every 3 square mile block, which might tie in to dozens of wells.

This was nothing really new. There are thousands of saltwater injection wells in the state, and there had been no induced seismicity.

This are was different, though. It involved a LOT of saltwater, and the injection wells were regularly scattered throughout the play.

The zone that everyone typically uses for an injection formaton in Oklahoma, Kansas, and much of Texas is the Arbuckle Dolomite, a very thick sequence of highly porous and permeable rock that lies beneath the oil production zones. The Arbuckle was already full of saltwater, and it is deep enough to prevent cross flow to another wellbore nearby. Nobody drills to the Arbuckle in these areas other than disposal wells. It's always been full of saltwater and always will be full of saltwater. In the Hunton production area it is about 1000 feet beneath the oil/saltwater producing Hunton zone. So you are taking water out of one zone and then injecting it into a deeper zone where it is safely out of the way. Back in the 20's, they would let saltwater run down creeks, and the super high chlorides would kill everything. After many decades, those areas have recovered, but a saltwater spill is considered just as bad as a land oil spill if both are small. Oil will get eaten by bacteria long before the chlorides can be washed out of the soil.

This is an important point: Saltwater is BAD. Think of frack flowback water as saltwater. It is usually far saltier than the ocean and contains contaminant minerals, but isn't considered hazardous waste. That is why offshore production can simply dump their saltwater into the ocean. Those wells don't typically produce much water, and it gets instantly diluted. This has been looked at from every angle, and even frack flowback fluid is almost all water, now contaminated with saltwater from the formation that you fracked. You can do a lot to clean up water, but it is extremely difficult to remove chlorides. That is why Pennsylvania was stupid to try to run it through municipal treatment plants.

All of these zones are deep, too. Overlain by miles of shale, sandstones, and limestones. Every pore space is filled with either saltwater, oil, or gas, basically. You can drill through a hundred porous zones full of saltwater just to get to a ten foot thick sandstone oil accumulation.

The only reason that you can even frack some of these organic rich shales is because they have a very high silica content. Numbers like Young's modulus and Poisson's Ratio are very important when drilling horizontals in the shales. They typically have zones of more ductile clay, which you can't frack, and zones of brittle high silica shale, which you can.

A horizontal well must be steered in a small stratigraphic interval, sometimes less than 30 feet thick, for it to be successful. A one mile lateral might have 30 sets of perforations, each requiring its own stage of the frack job. If the wellbore gets out of zone and into a ductile clay zone, you can pump into at at 10,000psi for days and never be able to inject the fluid for a successful frack. Today's wells are really considered to be successful on how many stages accepted the full amount of proppant.

These shales are overlain by thousands of feet of normal ductile clay rich shale with no hydrocarbons. You can't frack that with atomic bombs, and it was tried by the DOE in the fifties in Colorado and New Mexico.

OK. Saltwater and frack flowback handling are the big problems with these fracks. They are no different from a smaller frack on a vertical well other than their massive amount of fluid and sand.

Pennsylvania doesn't have a good disposal zone like the Arbuckle. They are trying all kinds of ways to recycle the frack flow back. There are already recycling systems being built in the SCOOP Woodford shale oil play in SW Oklahoma. They take that flowback, clean out the solids, and use it over and over again, which is a great help. This technology is going to be the future of how to handle frack flowback water.

More on Earthquakes later. It is not a shale. It is a thick, naturally fractured limestone that is being drilled up all over northern Oklahoma. The Mississippian Lime reservoir is famous for producing tons of saltwater. Like in that older Hunton play just NE of OKC, where we had a 5.6 several years ago, you have to tie in these wells to centralized saltwater disposal wells.

You increase the pore pressure and it can lubricate a fault, even a fault that hasn't moved in 200 million years. This is what we are seeing in Oklahoma right now. It is a horizontal play, but it isn't a shale. Shales don' make that much saltwater after they have flowed back the frack load. The Mississippian can produce with a 5% oil cut. 95% of the production is saltwater. At these oil prices, it is economic to produce that small of an oil cut as long as the overall fluid rates are huge.

Almost none of this has been published, but it is what is happening.

I can go into it more if anyone likes.
mike m

Trad climber
black hills
Sep 20, 2014 - 12:26pm PT
Seems like good economic development to me.

Social climber
An Oil Field
Sep 20, 2014 - 12:35pm PT
If done the right way, it is. The downside is that the shale gas wells drain a very small area, so you have to drill a lot of wells from each pad.

Each one involves an unreal amount of trucking to bring in the water and sand. It tears up the roads, is a damn nuisance, and affects the landscape, which is almost all farms.

I remember when they drilled up the Woodford Shale in the Arkoma basin in SE Oklahoma. There were endless trucks for several years. Now it has been mostly developed and it has died down. The collapse in nat gas prices has also halted a lot of drilling.

Trad climber
Leading Edge of North American Plate
Sep 20, 2014 - 02:53pm PT
I was amazed that people latched on to fracking and made it a "problem."

BASE104: although the Gasland films were full of inaccuracies and disinformation and I agree the mainstream media almost never reports any of this accurately, the environmental impacts of hydrofracking is NOT zero. In fact, you just enumerated some of the environmental issues above (i.e., increased traffic & congestion, air pollution, enormous amounts of fluids that need to be handled properly, etc.).

The myth propagated by the oil industry is that because there is no evidence that fractures induced in low permeability formations at depth have propagated upward and directly impacted shallow drinking water aquifers, that these operations are entirely environmentally safe.

Here's a list of impacts to be considered as part of an environmental assessment by the US Agency of International Development (USAID) for the development on shale gas in the Ukraine...

Water pollution from storing and transporting chemicals and fuels

Contaminated drinking water from escaped gas/chemicals

GHG emissions from extraction and production of gas

Leakage of VOCs from gas wells and compressor stations

Changes in sub-surface hydrology, including long-term damage to aquifers from fracturing chemicals

Safety and air pollution impacts from well fires and blowouts

Contamination of soils and water from drill cuttings and flowback fluids (heavy metals, naturally occurring radioactive materials, and other pollutants )

Local impacts and economic disruption from influx of construction personnel and support services

Air pollution due to truck traffic and mobile generators

Impacts from new road building

Impacts from new lands development

Wetland/habitat degradation

Impacts to any Endangered Species

Impacts to Nearby Residents Damage to existing roads

Trad climber
South Pasadena, CA
Sep 20, 2014 - 05:26pm PT
Hi Base104, can you talk about the composition of the fracking fluid and substances that are injected? Your summary seems qualitatively different from what I had read about in the past. A quick search turned up this:

Carcinogenic hydrocarbons used as solvents, and radioactive tracers... with large volumes of fracking, even low percentages of these components adds up to a lot of volume of nasty stuff being hauled in, aside from chloride and "saltwater," and low concentrations of some of these things leaking into groundwater can be a long term nightmare.

Social climber
So Cal
Sep 20, 2014 - 05:37pm PT
can you talk about the composition of the fracking fluid and substances that are injected?


a little of this.

(mineral oil)

and a little of this,


BTW that "evil" Halliburton has recently developed an NSF (National Sanitary Foundation, Writes the rules for what can be in contact with drinking water) approvable fracking fluid.

Social climber
An Oil Field
Sep 21, 2014 - 03:30pm PT
Yeah, they now have green frack fluids. I dunno how often they are used.

In one of the shale plays in Oklahoma, Continental has built two big water recycling centers. That is the way of the future.

It is so fashionable in journalism to paint these slick water fracks as some toxic brew injected into the ground. People just don't understand how oil and gas is found. I'll post up a geophysical log of a well for you guys to look at.

When drilling a well, after you reach total depth you call the logging company. Schlumberger is the best, but I've been using Weatherford a lot.

You lower these "tools," which look like twenty foot long stainless steel rods about 3 inches in diameter down the hole. You then turn on the logs and pull them up at a pretty slow rate. It can take all day to log a well if you have multiple runs. The tools have many instruments in them that measure porosity, permeability, lithology, fluid content, etc.

You evaluate the logs and then decide if you are going to plug the well or set production casing and complete it. I can look at a log and tell you a LOT. Very high technology. That is how I work. I spend all day building cross sections and correlating strata across areas in the producing basins.

The way that I have made most of my money is by finding zones that companies drilled right through and ignored, or didn't notice because of the poor technology in the 40's and 50's. So I look at a shitload of logs.

Trad climber
Leading Edge of North American Plate
Sep 21, 2014 - 06:16pm PT
NutAgain!: here's another website that contains info RE the chemistry of frac fluids.


Mountain climber
Terence Wilson greeneck alleghenys,ny,
Sep 21, 2014 - 06:30pm PT
Hardly mineral oil ,water and sand ,aye?

Trad climber
Leading Edge of North American Plate
Sep 21, 2014 - 06:39pm PT
Environ. Sci.: Processes Impacts, 2014
Received 09 Jul 2014, Accepted 13 Aug 2014

Organic compounds in produced waters from shale gas wells

A detailed analysis is reported of the organic composition of produced water samples from typical shale gas wells in the Marcellus (PA), Eagle Ford (TX), and Barnett (NM) formations. The quality of shale gas produced (and frac flowback) waters is a current environmental concern and disposal problem for producers. Re-use of produced water for hydraulic fracturing is being encouraged; however, knowledge of the organic impurities is important in determining the method of treatment. The metal content was determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Mineral elements are expected depending on the reservoir geology and salts used in hydraulic fracturing; however, significant levels of other transition metals and heavier main group elements are observed. The presence of scaling elements (Ca and Ba) is related to the pH of the water rather than total dissolved solids (TDS). Using gas chromatography mass spectrometry (GC/MS) analysis of the chloroform extracts of the produced water samples, a plethora of organic compounds were identified. In each water sample, the majority of organics are saturated (aliphatic), and only a small fraction comes under aromatic, resin, and asphaltene categories. Unlike coalbed methane produced water it appears that shale oil/gas produced water does not contain significant quantities of polyaromatic hydrocarbons reducing the potential health hazard. Marcellus and Barnett produced waters contain predominantly C6C16 hydrocarbons, while the Eagle Ford produced water shows the highest concentration in the C17C30 range. The structures of the saturated hydrocarbons identified generally follows the trend of linear > branched > cyclic. Heterocyclic compounds are identified with the largest fraction being fatty alcohols, esters, and ethers. However, the presence of various fatty acid phthalate esters in the Barnett and Marcellus produced waters can be related to their use in drilling fluids and breaker additives rather than their presence in connate fluids. Halogen containing compounds are found in each of the water samples, and although the fluorocarbon compounds identified are used as tracers, the presence of chlorocarbons and organobromides formed as a consequence of using chlorine containing oxidants (to remove bacteria from source water), suggests that industry should concentrate on non-chemical treatments of frac and produced waters.

Social climber
So Cal
Sep 21, 2014 - 06:41pm PT
Nothing particularly toxic either and at least several that are commonly used in drinking water treatment. (the pH adjusters and corrosion inhibitors.) Then there are others that are common in personal care products. (laurel sulphate for example. In your soap and shampoo)

Guar gum, a common thickener used in food products.

The primary constituents are still water, mineral oil and sand.

Trad climber
Leading Edge of North American Plate
Sep 21, 2014 - 06:47pm PT
Impacts of Shale Gas Wastewater Disposal on Water Quality in Western Pennsylvania

Nathaniel R. Warner *, Cidney A. Christie , Robert B. Jackson , and Avner Vengosh *
Division of Earth and Ocean Sciences, Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States

The safe disposal of liquid wastes associated with oil and gas production in the United States is a major challenge given their large volumes and typically high levels of contaminants. In Pennsylvania, oil and gas wastewater is sometimes treated at brine treatment facilities and discharged to local streams. This study examined the water quality and isotopic compositions of discharged effluents, surface waters, and stream sediments associated with a treatment facility site in western Pennsylvania. The elevated levels of chloride and bromide, combined with the strontium, radium, oxygen, and hydrogen isotopic compositions of the effluents reflect the composition of Marcellus Shale produced waters. The discharge of the effluent from the treatment facility increased downstream concentrations of chloride and bromide above background levels. Barium and radium were substantially (>90%) reduced in the treated effluents compared to concentrations in Marcellus Shale produced waters. Nonetheless, 226Ra levels in stream sediments (5448759 Bq/kg) at the point of discharge were ∼200 times greater than upstream and background sediments (2244 Bq/kg) and above radioactive waste disposal threshold regulations, posing potential environmental risks of radium bioaccumulation in localized areas of shale gas wastewater disposal.


Mountain climber
Terence Wilson greeneck alleghenys,ny,
Sep 21, 2014 - 06:48pm PT
TGT,I can read.

Those chems are all good to pump in the ground,right?


Trad climber
Leading Edge of North American Plate
Sep 21, 2014 - 07:11pm PT
If you're really interested in the environmental impacts of hydrofracking, I suggest you look at some of the recent publications in Environmental Science and Technology on this subject. Here's an abstract from one of the papers.

A Critical Review of the Risks to Water Resources from Unconventional Shale Gas Development and Hydraulic Fracturing in the United States

Avner Vengosh *, Robert B. Jackson , Nathaniel Warner , Thomas H. Darrah ̂∥, and Andrew Kondash
Division of Earth and Ocean Sciences, Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
School of Earth Sciences, Woods Institute for the Environment, and Precourt Institute for Energy, Stanford University, Stanford, California 94305, United States
Department of Earth Sciences, Dartmouth College, Hanover, New Hampshire 03755, United States
̂∥ School of Earth Sciences, The Ohio State University, Columbus, Ohio 43210, United States

Environ. Sci. Technol., 2014, 48 (15), pp 83348348
DOI: 10.1021/es405118y
Publication Date (Web): March 7, 2014
Copyright 2014 American Chemical Society

The rapid rise of shale gas development through horizontal drilling and high volume hydraulic fracturing has expanded the extraction of hydrocarbon resources in the U.S. The rise of shale gas development has triggered an intense public debate regarding the potential environmental and human health effects from hydraulic fracturing. This paper provides a critical review of the potential risks that shale gas operations pose to water resources, with an emphasis on case studies mostly from the U.S. Four potential risks for water resources are identified: (1) the contamination of shallow aquifers with fugitive hydrocarbon gases (i.e., stray gas contamination), which can also potentially lead to the salinization of shallow groundwater through leaking natural gas wells and subsurface flow; (2) the contamination of surface water and shallow groundwater from spills, leaks, and/or the disposal of inadequately treated shale gas wastewater; (3) the accumulation of toxic and radioactive elements in soil or stream sediments near disposal or spill sites; and (4) the overextraction of water resources for high-volume hydraulic fracturing that could induce water shortages or conflicts with other water users, particularly in water-scarce areas. Analysis of published data (through January 2014) reveals evidence for stray gas contamination, surface water impacts in areas of intensive shale gas development, and the accumulation of radium isotopes in some disposal and spill sites. The direct contamination of shallow groundwater from hydraulic fracturing fluids and deep formation waters by hydraulic fracturing itself, however, remains controversial.

Somewhere out there
Oct 16, 2014 - 09:14pm PT

 living in the belly of the beast... keeping tabs of my drinking water from the tap...

Boulder climber
Oct 16, 2014 - 09:26pm PT
You guys listen to way too much NPR.
Dingus Milktoast

Gym climber
Maestro, Ecosystem Ministry, Fatcrackistan
Nov 12, 2014 - 06:40pm PT
Another!!!!!! South Kansas earthquake attributed to the benign hydrofracking.

Queue oilmen saying 'everything is SNAFU!'


Somewhere out there
Nov 12, 2014 - 07:58pm PT
Wait until you are in the hot zones... <br/>
Then the water tastes real ni...
Wait until you are in the hot zones...
Then the water tastes real nice... fiery!

Credit: Jingy

When can you expect to taste the fracking rainbow?

Mountain climber
Terence Wilson greeneck alleghenys,ny,
Nov 13, 2014 - 05:34am PT
"WE" already have.

And ,yes,somebody is nuts.


Living just downstream of Pennsylvania.

Trad climber
Leading Edge of North American Plate
Nov 13, 2014 - 08:22am PT
Boron and Lithium isotopic signatures in "flowback fluids" now being used as tracers to evaluate environmental impacts of fracking operations

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